Navigational stars
Encyclopedia
Fifty-eight selected navigational star
s are given a special status in the field of celestial navigation
. Of the approximately 6,000 stars visible to the naked eye under optimal conditions, the selected stars are among the brightest and span thirty-eight constellation
s of the celestial sphere
from the declination
of 70° south to 89° north. Many of the selected stars were named in antiquity by the ancient Arabs, Greeks, Romans, and Babylonians.
The star Polaris
, often called the "North Star", is treated specially due to its proximity to the north celestial pole. When navigating in the northern hemisphere
, special techniques can be used with Polaris to determine latitude
or gyrocompass error
. The other 57 selected stars have daily positions given in nautical almanac
s, aiding the navigator
in efficiently performing observations on them. A second group of 115 "tabulated stars" can also be used for celestial navigation, but are often less familiar to the navigator and require extra calculations.
For purposes of identification, the positions of navigational stars — expressed as declination and sidereal hour angle — are often rounded to the nearest degree. In addition to tables, star chart
s provide an aid to the navigator in identifying the navigational stars, showing constellations, relative positions, and brightness.
which the two organizations have published jointly since 1958. Criteria in the choice of stars includes their distribution across the celestial sphere, brightness, and ease of identification. Information for another 115 stars, known as "tabulated stars", is also available to the navigator. This list provides information on the name, approximate position in the celestial sphere, and apparent magnitude
of the 58 selected stars in tabular form and by star charts.
These stars are typically used in two ways by the navigator. The first is to obtain a line of position by use of a sextant
observation and the techniques of celestial navigation. Multiple lines of position can be intersected to obtain a position known as a celestial fix. The second typical use of the navigational stars is to determine gyrocompass error by computing the azimuth of a star and comparing it to an azimuth measured using the ship's gyrocompass. Numerous other applications also exist.
Navigators typically refer to stars using one of two naming systems for stars: common names and Bayer's designations. All of the selected stars have had a common name since 1953, and many were named in antiquity by the Arabs, Greeks, Romans, and Babylonians. Bayer's naming convention has been in use since 1603, and consists of a Greek letter combined with the possessive form of the star's constellation. Both names are shown for each star in the tables and charts below.
Each star's approximate position on the celestial sphere is given using the equatorial coordinate system
. The celestial sphere is an imaginary globe of infinite size with the Earth at its center. Positions on the celestial sphere are often expressed using two coordinates: declination
and sidereal hour angle, which are similar to latitude and longitude
on the surface of the Earth. To define declination, the Earth's equator
is projected out to the celestial sphere to construct the celestial equator
, and declination is measured in degrees north or south of this celestial equator. Sidereal hour angle is a measurement between 0 and 360 degrees, indicating how far west a body is from an arbitrarily chosen line on the celestial sphere called the vernal equinox.
The final characteristic provided in the tables and star charts is the star's brightness, expressed in terms of apparent magnitude. Magnitude is a logarithmic scale of brightness, designed so that a body of one magnitude is approximately 2.512 times brighter than a body of the next magnitude.The value is actually the fifth root of 100, an irrational number
known as Pogson's Ratio. See Thus, a body of magnitude 1 is 2.5125, or 100 times brighter than a body of magnitude 6. The dimmest stars that can be seen through a 200-inch terrestrial telescope are of the 20th magnitude, and very bright objects like the Sun and a full Moon have magnitudes of −26.7 and −12.6 respectively.
The table of navigational stars provides several types of information. In the first column is the identifying index number, followed by the common name, the Bayer designation, and the etymology of the common name. Then the star's approximate position, suitable for identification purposes, is given in terms of declination and sidereal hour angle, followed by the star's magnitude. The final column presents citations to the sources of the data, The American Practical Navigator and the star's entry at the SIMBAD
database, a project of the Strasbourg Astronomical Data Center
or CDS.
Navigators often use star charts to identify a star by its position relative to other stars. References like the Nautical Almanac and The American Practical Navigator provide four star charts, covering different portions of the celestial sphere. Two of these charts are azimuthal equidistant projection
s of the north and south poles. The other two cover the equatorial region of the celestial sphere, from the declination of 30° south to 30° north. The two equatorial charts are mercator projection
s, one for the eastern hemisphere of the celestial sphere and one for the western hemisphere. Note that unlike familiar maps, east is shown to the left and west is shown to the right. With this orientation, the navigator can hold the star chart overhead, and the arrangement of the stars on the chart will resemble the stars in the sky.
In the star charts, constellations are labelled with capital letters and indicated by dotted lines collecting their stars. The 58 selected stars for navigation are shown in blue and labelled with their common name, star number, and a Greek letter to indicate their Bayer designation. The additional 115 tabulated stars that can also be used for navigation are shown in red and labelled with a Greek letter to indicate their Bayer designation. Some additional stars not suitable for navigation are also included on the charts to indicate constellations, they are presented as unlabelled small red dots.
The equatorial region of the celestial sphere's eastern hemisphere includes 16 navigational stars from Alpheratz in the constellation Andromeda to Denebola in Leo. It also includes stars from the constellations Cetus, Aries, Taurus, Orion, Canis Major and Minor, Gemini, and Hydra. Of particular note among these stars are "the dog star" Sirius, the brightest star in the sky, and four stars of the easily identified constellation Orion.
Image:Bowditch-equatorial-stars-180-360.svg|center|600px|alt=Equatorial stars with SHA from 180 to 360|
rect 767 236 803 264 Diphda (#4) SHA 349 Dec. S 18
rect 672 37 708 71 Hamal (#6) SHA 328 Dec. N 23
rect 616 134 657 178 Menkar (#8) SHA 315 Dec. N 04
rect 513 72 544 106 Aldebaran (#10) SHA 291 Dec. N 16
rect 474 192 508 225 Rigel (#11) SHA 282 Dec. S 08
rect 466 124 491 154 Bellatrix (#13) SHA 279 Dec. N 06
rect 460 18 486 45 Elnath (#14) SHA 279 Dec. N 29
rect 454 162 472 184 Alnilam (#15) SHA 276 Dec. S 01
rect 416 108 461 159 Betelgeuse (#16) SHA 271 Dec. N 07
rect 375 228 407 266 Sirius (#18) SHA 259 Dec. S 17
rect 363 293 397 320 Adhara (#19) SHA 256 Dec. S 29
rect 313 130 352 165 Procyon (#20) SHA 245 Dec. N 05
rect 304 21 347 54 Pollux (#21) SHA 244 Dec. N 28
rect 199 195 232 232 Alphard (#25) SHA 218 Dec. S 09
rect 803 13 840 46 Alpheratz (#1) SHA 358 Dec. N 29
rect 154 95 192 135 Regulus (#26) SHA 208 Dec. N 12
rect 46 81 77 121 Denebola (#28) SHA 183 Dec. N 15
desc top-right
Equatorial stars of the western hemisphere
The equatorial region of the celestial sphere's western hemisphere includes 13 navigational stars from Gienah in the constellation Corvus to Markab in Pegasus. It also includes stars from the constellations Virgo, Bootes, Libra, Corona Borealis, Scorpio, Ophiuchus, Sagittarius, and Aquila. The variable star
Arcturus is the brightest star in this group.
Image:Bowditch-equatorial-stars-0-180.svg|center|600px|alt=Equatorial stars with SHA from 0 to 180|
rect 812 240 829 265 Geinah (#29) SHA 165 Dec. S 19
rect 731 206 760 236 Spica (#33) SHA 159 Dec. S 11
rect 673 63 707 105 Arcturus (#37) SHA 146 Dec. N 19
rect 634 228 665 262 Zubenelgenubi (#39) SHA 138 Dec. S 16
rect 587 27 627 62 Alphecca (#41) SHA 127 Dec. N 27
rect 525 279 558 309 Antares (#42) SHA 113 Dec. S 26
rect 477 228 513 259 Sabik (#44) SHA 103 Dec. S 16
rect 456 92 489 124 Rasalhague (#46) SHA 096 Dec. N 13
rect 364 277 400 309 Nunki (#50) SHA 076 Dec. S 26
rect 306 106 335 149 Altair (#51) SHA 063 Dec. N 19
rect 186 111 229 147 Enif (#54) SHA 034 Dec. N 10
rect 103 293 139 325 Fomalhaut (#56) SHA 016 Dec. S 30
rect 99 80 132 117 Markab (#57) SHA 014 Dec. N 15
rect 23 19 65 52 Alpheratz (#1) SHA 358 Dec. N 29
desc top-right
Image:Navigational-stars-above-30-degrees-north.svg|float|right|400px|alt=Northern navigational stars|
rect 93 183 121 212 Schedar (#3) SHA 350 Dec. N 56
rect 119 104 150 135 Mirfac (#9) SHA 309 Dec. N 50
rect 172 63 211 103 Capella (#12) SHA 281 Dec. N 46
rect 282 177 315 220 Dubhe (#27) SHA 194 Dec. N 62
rect 306 230 337 259 Alioth (#32) SHA 167 Dec. N 56
rect 315 267 345 297 Alkaid (#34) SHA 153 Dec. N 49
rect 240 243 269 267 Kochab (#40) SHA 137 Dec. N 74
rect 202 332 233 364 Eltanin (#47) SHA 091 Dec. N 51
rect 179 366 203 398 Vega (#49) SHA 081 Dec. N 39
rect 110 314 136 349 Deneb (#53) SHA 050 Dec. N 45
rect 198 199 230 235 Polaris SHA 319 Dec. N 89
desc top-right
The 11 northern stars are those with a declination between 30° north and 90° north. They are listed in order of decreasing sidereal hour angle, or from the vernal equinox westward across the sky. Starting with Schedar in the Cassiopeia constellation, the list includes stars from the constellations Auriga, the Great and Little Bears, Draco, Lyra and Cygnus. The two brightest northern stars are Vega and Capella.
In the star chart to the right, declination is shown by the radial coordinate, starting at 90° north in the center and decreasing to 30° north at the outer edge. Sidereal hour angle is shown as the angular coordinate, starting at 0° at the left of the chart, and increasing counter-clockwise.
Image:Navigational-stars-below-30-degrees-south.svg|float|right|400px|alt=Southern navigational stars|
rect 351 191 379 218 Ankaa (#2) SHA 354 Dec. S 42
rect 297 158 322 192 Achernar (#5) SHA 336 Dec. S 57
rect 311 94 341 121 Acamar (#7) SHA 316 Dec. S 40
rect 191 85 223 119 Canopus (#17) SHA 264 Dec. S 53
rect 146 129 171 156 Avior (#22) SHA 234 Dec. S 59
rect 92 105 123 135 Suhail (#23) SHA 223 Dec. S 43
rect 155 166 189 193 Miaplacidus (#24) SHA 222 Dec. S 70
rect 123 222 145 251 Acrux (#30) SHA 174 Dec. S 63
rect 102 227 120 247 Gacrux (#31) SHA 172 Dec. S 57
rect 122 262 146 280 Hadar (#35) SHA 149 Dec. S 60
rect 60 302 83 330 Menkent (#36) SHA 149 Dec. S 60
rect 135 278 158 299 Rigel Kentaurus (#38) SHA 140 Dec. S 61
rect 183 272 206 304 Atria (#43) SHA 108 Dec. S 69
rect 194 381 215 405 Shaula (#45) SHA 097 Dec. S 34
rect 224 394 249 416 Kaus Australis (#48) SHA 084 Dec. S 34
rect 268 299 292 321 Peacock (#52) SHA 054 Dec. S 57
rect 322 278 347 304 Al Na'ir (#55) SHA 028 Dec S 47
rect 385 262 414 286 Fomalhaut (#56) SHA 016 Dec. S 30
desc top-right
The 18 southern stars are those with a declination between 30° south and 90° south. They are listed in order of decreasing sidereal hour angle, or from the vernal equinox westward across the sky. Starting with Ankaa in the Phoenix constellation, the list includes stars from the constellations Eridanus, Carina, Crux, Centaurus, Libra, Triangulum Australe, Scorpio, Sagittarius, Pavo, and Grus. Canopus, Rigil Kentaurus, Achernar, and Hadar are the brightest stars in the southern sky.
In the star chart to the right, declination is shown by the radial coordinate, starting at 90° north in the center and decreasing to 30° north at the outer edge. Sidereal hour angle is shown as the angular coordinate, starting at 0° at the right of the chart, and increasing clockwise.
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
s are given a special status in the field of celestial navigation
Celestial navigation
Celestial navigation, also known as astronavigation, is a position fixing technique that has evolved over several thousand years to help sailors cross oceans without having to rely on estimated calculations, or dead reckoning, to know their position...
. Of the approximately 6,000 stars visible to the naked eye under optimal conditions, the selected stars are among the brightest and span thirty-eight constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
s of the celestial sphere
Celestial sphere
In astronomy and navigation, the celestial sphere is an imaginary sphere of arbitrarily large radius, concentric with the Earth and rotating upon the same axis. All objects in the sky can be thought of as projected upon the celestial sphere. Projected upward from Earth's equator and poles are the...
from the declination
Declination
In astronomy, declination is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. Declination in astronomy is comparable to geographic latitude, but projected onto the celestial sphere. Declination is measured in degrees north and...
of 70° south to 89° north. Many of the selected stars were named in antiquity by the ancient Arabs, Greeks, Romans, and Babylonians.
The star Polaris
Polaris
Polaris |Alpha]] Ursae Minoris, commonly North Star or Pole Star, also Lodestar) is the brightest star in the constellation Ursa Minor. It is very close to the north celestial pole, making it the current northern pole star....
, often called the "North Star", is treated specially due to its proximity to the north celestial pole. When navigating in the northern hemisphere
Northern Hemisphere
The Northern Hemisphere is the half of a planet that is north of its equator—the word hemisphere literally means “half sphere”. It is also that half of the celestial sphere north of the celestial equator...
, special techniques can be used with Polaris to determine latitude
Latitude
In geography, the latitude of a location on the Earth is the angular distance of that location south or north of the Equator. The latitude is an angle, and is usually measured in degrees . The equator has a latitude of 0°, the North pole has a latitude of 90° north , and the South pole has a...
or gyrocompass error
Gyrocompass
A gyrocompass is a type of non-magnetic compass which bases on a fast-spinning disc and rotation of our planet to automatically find geographical direction...
. The other 57 selected stars have daily positions given in nautical almanac
Nautical almanac
A nautical almanac is a publication describing the positions of a selection of celestial bodies for the purpose of enabling navigators to use celestial navigation to determine the position of their ship while at sea...
s, aiding the navigator
Second Mate
A second mate or second officer is a licensed member of the deck department of a merchant ship. The second mate is the third in command and a watchkeeping officer, customarily the ship's navigator. Other duties vary, but the second mate is often the medical officer and in charge of maintaining...
in efficiently performing observations on them. A second group of 115 "tabulated stars" can also be used for celestial navigation, but are often less familiar to the navigator and require extra calculations.
For purposes of identification, the positions of navigational stars — expressed as declination and sidereal hour angle — are often rounded to the nearest degree. In addition to tables, star chart
Star chart
A star chart is a map of the night sky. Astronomers divide these into grids to use them more easily. They are used to identify and locate astronomical objects such as stars, constellations and galaxies. They have been used for human navigation since time immemorial...
s provide an aid to the navigator in identifying the navigational stars, showing constellations, relative positions, and brightness.
Background
Under optimal conditions, approximately 6,000 stars are visible to the naked eye of an observer on Earth. Of these, 58 are known in the field of navigational astronomy as "selected stars", including 19 stars of the first magnitude, 38 stars of the second magnitude, and Polaris. The selection of the stars is made by Her Majesty's Nautical Almanac Office and the US Naval Observatory, in the production of the yearly Nautical AlmanacNautical Almanac
Nautical Almanac can refer to:* Nautical almanac - a publication describing the positions and movements of celestial bodies* American Ephemeris and Nautical Almanac - first published in 1852* U.S...
which the two organizations have published jointly since 1958. Criteria in the choice of stars includes their distribution across the celestial sphere, brightness, and ease of identification. Information for another 115 stars, known as "tabulated stars", is also available to the navigator. This list provides information on the name, approximate position in the celestial sphere, and apparent magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
of the 58 selected stars in tabular form and by star charts.
These stars are typically used in two ways by the navigator. The first is to obtain a line of position by use of a sextant
Sextant
A sextant is an instrument used to measure the angle between any two visible objects. Its primary use is to determine the angle between a celestial object and the horizon which is known as the altitude. Making this measurement is known as sighting the object, shooting the object, or taking a sight...
observation and the techniques of celestial navigation. Multiple lines of position can be intersected to obtain a position known as a celestial fix. The second typical use of the navigational stars is to determine gyrocompass error by computing the azimuth of a star and comparing it to an azimuth measured using the ship's gyrocompass. Numerous other applications also exist.
Navigators typically refer to stars using one of two naming systems for stars: common names and Bayer's designations. All of the selected stars have had a common name since 1953, and many were named in antiquity by the Arabs, Greeks, Romans, and Babylonians. Bayer's naming convention has been in use since 1603, and consists of a Greek letter combined with the possessive form of the star's constellation. Both names are shown for each star in the tables and charts below.
Each star's approximate position on the celestial sphere is given using the equatorial coordinate system
Equatorial coordinate system
The equatorial coordinate system is a widely-used method of mapping celestial objects. It functions by projecting the Earth's geographic poles and equator onto the celestial sphere. The projection of the Earth's equator onto the celestial sphere is called the celestial equator...
. The celestial sphere is an imaginary globe of infinite size with the Earth at its center. Positions on the celestial sphere are often expressed using two coordinates: declination
Declination
In astronomy, declination is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. Declination in astronomy is comparable to geographic latitude, but projected onto the celestial sphere. Declination is measured in degrees north and...
and sidereal hour angle, which are similar to latitude and longitude
Longitude
Longitude is a geographic coordinate that specifies the east-west position of a point on the Earth's surface. It is an angular measurement, usually expressed in degrees, minutes and seconds, and denoted by the Greek letter lambda ....
on the surface of the Earth. To define declination, the Earth's equator
Equator
An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....
is projected out to the celestial sphere to construct the celestial equator
Celestial equator
The celestial equator is a great circle on the imaginary celestial sphere, in the same plane as the Earth's equator. In other words, it is a projection of the terrestrial equator out into space...
, and declination is measured in degrees north or south of this celestial equator. Sidereal hour angle is a measurement between 0 and 360 degrees, indicating how far west a body is from an arbitrarily chosen line on the celestial sphere called the vernal equinox.
The final characteristic provided in the tables and star charts is the star's brightness, expressed in terms of apparent magnitude. Magnitude is a logarithmic scale of brightness, designed so that a body of one magnitude is approximately 2.512 times brighter than a body of the next magnitude.The value is actually the fifth root of 100, an irrational number
Irrational number
In mathematics, an irrational number is any real number that cannot be expressed as a ratio a/b, where a and b are integers, with b non-zero, and is therefore not a rational number....
known as Pogson's Ratio. See Thus, a body of magnitude 1 is 2.5125, or 100 times brighter than a body of magnitude 6. The dimmest stars that can be seen through a 200-inch terrestrial telescope are of the 20th magnitude, and very bright objects like the Sun and a full Moon have magnitudes of −26.7 and −12.6 respectively.
Table
| Key to the table | |
|---|---|
| Column title | Description |
| No. | The number used to identify stars in navigation publications and star charts. |
| Common name | The name of the star commonly used navigation publications and star charts. |
| Bayer designation Bayer designation A Bayer designation is a stellar designation in which a specific star is identified by a Greek letter, followed by the genitive form of its parent constellation's Latin name... |
Another name of the star which combines a Greek letter Greek alphabet The Greek alphabet is the script that has been used to write the Greek language since at least 730 BC . The alphabet in its classical and modern form consists of 24 letters ordered in sequence from alpha to omega... with the possessive form of its constellation's Latin name. |
| Etymology of common name |
Etymology of the common name. |
| SHA | Sidereal hour angle (SHA) Hour angle In astronomy and celestial navigation, the hour angle is one of the coordinates used in the equatorial coordinate system to give the position of a point on the celestial sphere.... , the angular distance west of the vernal equinox. |
| Dec. | Declination Declination In astronomy, declination is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. Declination in astronomy is comparable to geographic latitude, but projected onto the celestial sphere. Declination is measured in degrees north and... , the angular distance north or south of the celestial equator Celestial equator The celestial equator is a great circle on the imaginary celestial sphere, in the same plane as the Earth's equator. In other words, it is a projection of the terrestrial equator out into space... . |
| App. magnitude Apparent magnitude The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere... |
Apparent magnitude, an indicator of the star's brightness. |
The table of navigational stars provides several types of information. In the first column is the identifying index number, followed by the common name, the Bayer designation, and the etymology of the common name. Then the star's approximate position, suitable for identification purposes, is given in terms of declination and sidereal hour angle, followed by the star's magnitude. The final column presents citations to the sources of the data, The American Practical Navigator and the star's entry at the SIMBAD
SIMBAD
SIMBAD is an astronomical database of objects beyond the Solar System...
database, a project of the Strasbourg Astronomical Data Center
Centre de Données astronomiques de Strasbourg
The Centre de données astronomiques de Strasbourg is a data hub which collects and distributes astronomical information. It was established in 1972 under the name Centre de Données Stellaires...
or CDS.
| No. | Common name |
Bayer designation Bayer designation A Bayer designation is a stellar designation in which a specific star is identified by a Greek letter, followed by the genitive form of its parent constellation's Latin name... |
Etymology of common name | SHA Hour angle In astronomy and celestial navigation, the hour angle is one of the coordinates used in the equatorial coordinate system to give the position of a point on the celestial sphere.... |
Dec. | App. magnitude Apparent magnitude The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere... |
References |
|---|---|---|---|---|---|---|---|
| 1 | Alpheratz Alpha Andromedae Alpha Andromedae , which has the traditional names Alpheratz and Sirrah , is the brightest star in the constellation of Andromeda. Located immediately northeast of the constellation of Pegasus, it is the northeastern star of the Great Square of Pegasus... |
α Andromedae Andromeda (constellation) Andromeda is a constellation in the northern sky. It is named after Andromeda, the princess in the Greek legend of Perseus who was chained to a rock to be eaten by the sea monster Cetus... |
the horse Pegasus (constellation) Pegasus is a constellation in the northern sky, named after the winged horse Pegasus in Greek mythology. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations.-Stars:... 's navel |
358 | N 29° | 2.06 | |
| 2 | Ankaa Alpha Phoenicis Alpha Phoenicis is the brightest star in the constellation Phoenix. It has the traditional name Ankaa, from the Arabic العنقاء al-‘anqā’ "the phoenix"... |
α Phoenicis Phoenix (constellation) Phoenix is a minor constellation in the southern sky. It is named after the Phoenix, a mythical bird. It is faint: there are only two stars in the whole constellation which are brighter than magnitude 5.0... |
coined name | 354 | S 42° | 2.37 | |
| 3 | Schedar Alpha Cassiopeiae Alpha Cassiopeiae is a second magnitude star in the constellation Cassiopeia, with the traditional name Schedar, sometimes spelt Shedir. Though listed as the alpha star by Johann Bayer, Schedar's visual brightness closely rivals the beta star in the constellation, Caph... |
α Cassiopeiae Cassiopeia (constellation) Cassiopeia is a constellation in the northern sky, named after the vain queen Cassiopeia in Greek mythology, who boasted about her unrivalled beauty. Cassiopea was one of the 48 constellations listed by the 2nd century Greek astronomer Ptolemy, and it remains one of the 88 modern constellations today... |
the breast (of Cassiopeia Cassiopeia (constellation) Cassiopeia is a constellation in the northern sky, named after the vain queen Cassiopeia in Greek mythology, who boasted about her unrivalled beauty. Cassiopea was one of the 48 constellations listed by the 2nd century Greek astronomer Ptolemy, and it remains one of the 88 modern constellations today... ) |
350 | N 56° | 2.25 | |
| 4 | Diphda Beta Ceti Beta Ceti is the brightest star in the constellation Cetus. Although it has the Bayer designation "beta", it is actually brighter than Alpha Ceti. It has the traditional names Deneb Kaitos and Diphda... |
β Ceti Cetus Cetus is a constellation. Its name refers to Cetus, a sea monster in Greek mythology, although it is often called 'the whale' today. Cetus is located in the region of the sky that contains other water-related constellations such as Aquarius, Pisces, and Eridanus.-Ecliptic:Although Cetus is not... |
the second frog (Fomalhaut Fomalhaut Fomalhaut is the brightest star in the constellation Piscis Austrinus and one of the brightest stars in the sky. Fomalhaut can be seen low in the southern sky in the northern hemisphere in fall and early winter evenings. Near latitude 50˚N, it sets around the time Sirius rises, and does not... was once the first) |
349 | S 18° | 2.04 | |
| 5 | Achernar Achernar Achernar , sometimes spelled Achenar, is the brightest star in the constellation Eridanus and the ninth-brightest star in the night sky. Of the top ten apparent brightest stars —Sirius, Canopus, Alpha Centauri, Arcturus, Vega, Capella, Rigel, Procyon, Achernar and Betelgeuse—Achernar is the hottest... |
α Eridani Eridanus (constellation) Eridanus is a constellation. It is represented as a river; its name is the Ancient Greek name for the Po River. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations. It is the sixth largest of the modern... |
end of the river (Eridanus Eridanus (constellation) Eridanus is a constellation. It is represented as a river; its name is the Ancient Greek name for the Po River. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations. It is the sixth largest of the modern... ) |
336 | S 57° | 0.50 | |
| 6 | Hamal | α Arietis Aries (constellation) Aries is one of the constellations of the zodiac, located between Pisces to the west and Taurus to the east. Its name is Latin for ram, and its symbol is , representing a ram's horns... |
full-grown lamb Aries (constellation) Aries is one of the constellations of the zodiac, located between Pisces to the west and Taurus to the east. Its name is Latin for ram, and its symbol is , representing a ram's horns... |
328 | N 23° | 2.00 | |
| 7 | Acamar Theta Eridani Theta Eridani is a star in the constellation Eridanus. It has the traditional name Acamar from the Arabic آخِر النَّهْر Ākhir an-nahr which means "the end of the river". Historically, Acamar represented the end of the constellation Eridanus. Now that distinction is held by the star Achernar, a... |
θ Eridani Eridanus (constellation) Eridanus is a constellation. It is represented as a river; its name is the Ancient Greek name for the Po River. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations. It is the sixth largest of the modern... |
another form of Achernar | 316 | S 40° | 3.2 | |
| 8 | Menkar Alpha Ceti Alpha Ceti is a star in the constellation of Cetus. It has the traditional name Menkar or Menkab. The name Menkar derives from the Arabic word منخر manħar "nostril" .... |
α Ceti Cetus Cetus is a constellation. Its name refers to Cetus, a sea monster in Greek mythology, although it is often called 'the whale' today. Cetus is located in the region of the sky that contains other water-related constellations such as Aquarius, Pisces, and Eridanus.-Ecliptic:Although Cetus is not... |
nose (of the whale Cetus Cetus is a constellation. Its name refers to Cetus, a sea monster in Greek mythology, although it is often called 'the whale' today. Cetus is located in the region of the sky that contains other water-related constellations such as Aquarius, Pisces, and Eridanus.-Ecliptic:Although Cetus is not... ) |
315 | N 04° | 2.5 | |
| 9 | Mirfak Alpha Persei Alpha Persei is the brightest star in the constellation of Perseus, just outshining the constellation's best known star Algol. It also bears the traditional names Mirfak and Algenib... |
α Persei Perseus (constellation) Perseus is a constellation in the northern sky, named after the Greek hero Perseus. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations defined by the International Astronomical Union... |
elbow of the Pleiades Pleiades (star cluster) In astronomy, the Pleiades, or Seven Sisters , is an open star cluster containing middle-aged hot B-type stars located in the constellation of Taurus. It is among the nearest star clusters to Earth and is the cluster most obvious to the naked eye in the night sky... |
309 | N 50° | 1.82 | |
| 10 | Aldebaran Aldebaran Aldebaran is a red giant star located about 65 light years away in the zodiac constellation of Taurus. With an average apparent magnitude of 0.87 it is the brightest star in the constellation and is one of the brightest stars in the nighttime sky... |
α Tauri Taurus (constellation) Taurus is one of the constellations of the zodiac. Its name is a Latin word meaning 'bull', and its astrological symbol is a stylized bull's head:... |
follower (of the Pleiades Pleiades (star cluster) In astronomy, the Pleiades, or Seven Sisters , is an open star cluster containing middle-aged hot B-type stars located in the constellation of Taurus. It is among the nearest star clusters to Earth and is the cluster most obvious to the naked eye in the night sky... ) |
291 | N 16° | 0.85 var | |
| 11 | Rigel Rigel Rigel is the brightest star in the constellation Orion and the sixth brightest star in the sky, with visual magnitude 0.18... |
β Orionis Orion (constellation) Orion, often referred to as The Hunter, is a prominent constellation located on the celestial equator and visible throughout the world. It is one of the most conspicuous, and most recognizable constellations in the night sky... |
foot (left foot of Orion Orion (constellation) Orion, often referred to as The Hunter, is a prominent constellation located on the celestial equator and visible throughout the world. It is one of the most conspicuous, and most recognizable constellations in the night sky... ) |
282 | S 08° | 0.12 | |
| 12 | Capella Capella (star) Capella is the brightest star in the constellation Auriga, the sixth brightest star in the night sky and the third brightest star in the northern celestial hemisphere, after Arcturus and Vega. Although it appears to be a single star to the naked eye, it is actually a star system of four stars in... |
α Aurigae Auriga (constellation) Auriga is a constellation in the northern sky. Its name is Latin for 'charioteer' and its stars form a shape that has been associated with the pointed helmet of a charioteer. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains among the 88 modern... |
little she-goat | 281 | N 46° | 0.71 | |
| 13 | Bellatrix Gamma Orionis Bellatrix, also known by its Bayer designation Gamma Orionis , is the third brightest star in the constellation Orion, the twenty-seventh brightest star in the night sky, and one of the brightest second-magnitude stars.... |
γ Orionis Orion (constellation) Orion, often referred to as The Hunter, is a prominent constellation located on the celestial equator and visible throughout the world. It is one of the most conspicuous, and most recognizable constellations in the night sky... |
female warrior | 279 | N 06° | 1.64 | |
| 14 | Elnath Beta Tauri Beta Tauri is the second brightest star in the constellation Taurus, with an apparent magnitude of 1.68. Because it is on the boundary of Taurus and Auriga, it also has the redundant Bayer designation Gamma Aurigae , which today is rarely used... |
β Tauri Taurus (constellation) Taurus is one of the constellations of the zodiac. Its name is a Latin word meaning 'bull', and its astrological symbol is a stylized bull's head:... |
one butting with the horns | 279 | N 29° | 1.68 | |
| 15 | Alnilam Epsilon Orionis Alnilam is a large blue supergiant star in the constellation of Orion. Its Flamsteed designation is 46 Orionis.... |
ε Orionis Orion (constellation) Orion, often referred to as The Hunter, is a prominent constellation located on the celestial equator and visible throughout the world. It is one of the most conspicuous, and most recognizable constellations in the night sky... |
string of pearls | 276 | S 01° | 1.70 | |
| 16 | Betelgeuse Betelgeuse Betelgeuse, also known by its Bayer designation Alpha Orionis , is the eighth brightest star in the night sky and second brightest star in the constellation of Orion, outshining its neighbour Rigel only rarely... |
α Orionis Orion (constellation) Orion, often referred to as The Hunter, is a prominent constellation located on the celestial equator and visible throughout the world. It is one of the most conspicuous, and most recognizable constellations in the night sky... |
the arm pit (of Orion Orion (constellation) Orion, often referred to as The Hunter, is a prominent constellation located on the celestial equator and visible throughout the world. It is one of the most conspicuous, and most recognizable constellations in the night sky... ) |
271 | N 07° | 0.58 var | |
| 17 | Canopus Canopus Canopus |Alpha]] Carinae) is the brightest star in the southern constellation of Carina and Argo Navis, and the second brightest star in the night-time sky, after Sirius. Canopus's visual magnitude is −0.72, and it has an absolute magnitude of −5.53.Canopus is a supergiant of spectral... |
α Carinae Carina (constellation) Carina is a constellation in the southern sky. Its name is Latin for the keel of a ship, and it was formerly part of the larger constellation of Argo Navis until that constellation was divided in three.-Stars:... |
city of ancient Egypt Canopus, Egypt Canopus was an Ancient Egyptian coastal town, located in the Nile Delta. Its site is in the eastern outskirts of modern-day Alexandria, around 25 kilometres from the centre of that city.... |
264 | S 53° | −0.72 | |
| 18 | Sirius Sirius Sirius is the brightest star in the night sky. With a visual apparent magnitude of −1.46, it is almost twice as bright as Canopus, the next brightest star. The name "Sirius" is derived from the Ancient Greek: Seirios . The star has the Bayer designation Alpha Canis Majoris... |
α Canis Major Canis Major Canis Major is one of the 88 modern constellations, and was included in the 2nd-century astronomer Ptolemy's 48 constellations. Its name is Latin for 'greater dog', and is commonly represented as one of the dogs following Orion the hunter... is |
the scorching one (popularly, the dog star) | 259 | S 17° | −1.47 | |
| 19 | Adhara Epsilon Canis Majoris Epsilon Canis Majoris is the second brightest star in the constellation Canis Major, and one of the brightest stars in the night sky. It has the Bayer designation "epsilon" despite being the second brightest and not the fifth brightest star in its constellation. It has the traditional name Adhara... |
ε Canis Major Canis Major Canis Major is one of the 88 modern constellations, and was included in the 2nd-century astronomer Ptolemy's 48 constellations. Its name is Latin for 'greater dog', and is commonly represented as one of the dogs following Orion the hunter... is |
the virgin(s) | 256 | S 29° | 1.51 | |
| 20 | Procyon Procyon Procyon is the brightest star in the constellation Canis Minor. To the naked eye, it appears to be a single star, the seventh brightest in the night sky with a visual apparent magnitude of 0.34... |
α Canis Minor Canis Minor Canis Minor is a small constellation. It was included in the 2nd century astronomer Ptolemy's 48 constellations, and is still included among the 88 modern constellations... is |
before the dog (rising before the dog star, Sirius Sirius Sirius is the brightest star in the night sky. With a visual apparent magnitude of −1.46, it is almost twice as bright as Canopus, the next brightest star. The name "Sirius" is derived from the Ancient Greek: Seirios . The star has the Bayer designation Alpha Canis Majoris... ) |
245 | N 05° | 0.34 | |
| 21 | Pollux Pollux (star) Pollux is an orange giant star approximately 34 light-years from the Earth in the constellation of Gemini . Pollux is the brightest star in the constellation, brighter than Castor... |
β Geminorum Gemini (constellation) Gemini is one of the constellations of the zodiac. It was one of the 48 constellations described by the 2nd century astronomer Ptolemy and it remains one of the 88 modern constellations today. Its name is Latin for "twins", and it is associated with the twins Castor and Pollux in Greek mythology... |
Zeus Zeus In the ancient Greek religion, Zeus was the "Father of Gods and men" who ruled the Olympians of Mount Olympus as a father ruled the family. He was the god of sky and thunder in Greek mythology. His Roman counterpart is Jupiter and his Etruscan counterpart is Tinia.Zeus was the child of Cronus... ' other twin son (Castor Castor (star) Castor is the second brightest star in the constellation Gemini and one of the brightest stars in the night sky. Although it has the Bayer designation "alpha", it is actually fainter than Beta Geminorum... , α Gem, is the first twin) |
244 | N 28° | 1.15 | |
| 22 | Avior Epsilon Carinae Epsilon Carinae is a star in the constellation Carina. At apparent magnitude +1.86 it is one of the brightest stars in the night sky, but is not visible from the northern hemisphere.... |
ε1 Carinae Carina (constellation) Carina is a constellation in the southern sky. Its name is Latin for the keel of a ship, and it was formerly part of the larger constellation of Argo Navis until that constellation was divided in three.-Stars:... |
coined name | 234 | S 59° | 2.4 | |
| 23 | Suhail Lambda Velorum Lambda Velorum is a star in the constellation Vela. It has the traditional name Suhail .Lambda Velorum is a supergiant or bright giant star of spectral class K5... |
λ Velorum Vela (constellation) Vela is a constellation in the southern sky. Its name is Latin for the sails of a ship, and it was originally part of a larger constellation, the ship Argo Navis, which was later divided into three parts, the others being Carina and Puppis.-Stars:... |
shortened form of Al Suhail, one Arabic name for Canopus | 223 | S 43° | 2.23 | |
| 24 | Miaplacidus Beta Carinae Beta Carinae is the second brightest star in the constellation Carina and one of the brightest stars in the night sky, with apparent magnitude 1.68. It is the brightest star in the south polar asterism known as the Diamond Cross, marking the southwestern end of the asterism. Beta Carinae also has... |
β Carinae Carina (constellation) Carina is a constellation in the southern sky. Its name is Latin for the keel of a ship, and it was formerly part of the larger constellation of Argo Navis until that constellation was divided in three.-Stars:... |
quiet or still waters | 222 | S 70° | 1.70 | |
| 25 | Alphard Alphard Alphard is the brightest star in the constellation Hydra. The name Alphard is from the Arabic الفرد , "the solitary one", there being no other bright stars near it. It was also known as the "backbone of the Serpent" to the Arabs. In ancient China it formed part of an asterism called the "red bird"... |
α Hydrae Hydra (constellation) Hydra is the largest of the 88 modern constellations, measuring 1303 square degrees. It has a long history, having been included among the 48 constellations listed by the 2nd century astronomer Ptolemy. It is commonly represented as a water snake... |
solitary star of the serpent Hydra (constellation) Hydra is the largest of the 88 modern constellations, measuring 1303 square degrees. It has a long history, having been included among the 48 constellations listed by the 2nd century astronomer Ptolemy. It is commonly represented as a water snake... |
218 | S 09° | 2.00 | |
| 26 | Regulus Regulus Regulus is the brightest star in the constellation Leo and one of the brightest stars in the night sky, lying approximately 77.5 light years from Earth. Regulus is a multiple star system composed of four stars which are organized into two pairs... |
α Leonis Leo (constellation) Leo is one of the constellations of the zodiac. Its name is Latin for lion. Its symbol is . Leo lies between dim Cancer to the west and Virgo to the east.-Stars:... |
the prince | 208 | N 12° | 1.35 | |
| 27 | Dubhe | α1 Ursae Majoris Ursa Major Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April... |
the bear Ursa Major Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April... 's back |
194 | N 62° | 1.87 | |
| 28 | Denebola | β Leonis Leo (constellation) Leo is one of the constellations of the zodiac. Its name is Latin for lion. Its symbol is . Leo lies between dim Cancer to the west and Virgo to the east.-Stars:... |
tail of the lion Leo (constellation) Leo is one of the constellations of the zodiac. Its name is Latin for lion. Its symbol is . Leo lies between dim Cancer to the west and Virgo to the east.-Stars:... |
183 | N 15° | 2.14 | |
| 29 | Gienah Gamma Corvi Gamma Corvi is the brightest star in the constellation Corvus. Its traditional name is Gienah, which it shares with Epsilon Cygni... |
γ Corvi Corvus (constellation) Corvus is a small constellation in the southern sky. Its name is Latin for raven or crow. It includes only 11 stars visible to the naked eye... |
right wing of the raven Corvus (constellation) Corvus is a small constellation in the southern sky. Its name is Latin for raven or crow. It includes only 11 stars visible to the naked eye... |
176 | S 17° | 2.80 | |
| 30 | Acrux | α1 Crucis Crux Crux is the smallest of the 88 modern constellations, but is one of the most distinctive. Its name is Latin for cross, and it is dominated by a cross-shaped asterism that is commonly known as the Southern Cross.-Visibility:... |
coined from Bayer name | 174 | S 63° | 1.40 | |
| 31 | Gacrux | γ Crucis Crux Crux is the smallest of the 88 modern constellations, but is one of the most distinctive. Its name is Latin for cross, and it is dominated by a cross-shaped asterism that is commonly known as the Southern Cross.-Visibility:... |
coined from Bayer name | 172 | S 57° | 1.63 | |
| 32 | Alioth Epsilon Ursae Majoris Epsilon Ursae Majoris is the brightest star in the constellation Ursa Major , and at magnitude 1.76 is the thirty-first brightest star in the sky... |
ε Ursae Majoris Ursa Major Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April... |
another form of Capella | 167 | N 56° | 1.76 | |
| 33 | Spica Spica Spica is the brightest star in the constellation Virgo, and the 15th brightest star in the nighttime sky. It is 260 light years distant from Earth... |
α Virginis Virgo (constellation) Virgo is one of the constellations of the zodiac. Its name is Latin for virgin, and its symbol is . Lying between Leo to the west and Libra to the east, it is the second largest constellation in the sky... |
the ear of corn | 159 | S 11° | 1.04 | |
| 34 | Alkaid Eta Ursae Majoris Eta Ursae Majoris is a star in the constellation Ursa Major. It has the traditional names Alkaid and Benetnash .... |
η Ursae Majoris Ursa Major Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April... |
leader of the daughters of the bier | 153 | N 49° | 1.85 | |
| 35 | Hadar Beta Centauri Beta Centauri , also known as Hadar or Agena, is the second brightest star in the constellation Centaurus and the tenth brightest star in the night sky. Beta Centauri is a B1 III blue-white giant star that the astrometric Hipparcos satellite calculates as about 161 parsecs or 525 light-years from... |
β Centauri Centaurus Centaurus is a bright constellation in the southern sky. One of the largest constellations, Centaurus was included among the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations.-Stars:... |
leg of the centaur Centaurus Centaurus is a bright constellation in the southern sky. One of the largest constellations, Centaurus was included among the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations.-Stars:... |
149 | S 60° | 0.60 | |
| 36 | Menkent Theta Centauri Theta Centauri is a star in the constellation Centaurus. It is also has the traditional Arabic name Menkent... |
θ Centauri Centaurus Centaurus is a bright constellation in the southern sky. One of the largest constellations, Centaurus was included among the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations.-Stars:... |
shoulder of the centaur Centaurus Centaurus is a bright constellation in the southern sky. One of the largest constellations, Centaurus was included among the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations.-Stars:... |
149 | S 36° | 2.06 | |
| 38 | Rigil Kentaurus | α1 Centauri Centaurus Centaurus is a bright constellation in the southern sky. One of the largest constellations, Centaurus was included among the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations.-Stars:... |
foot of the centaur Centaurus Centaurus is a bright constellation in the southern sky. One of the largest constellations, Centaurus was included among the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations.-Stars:... |
140 | S 61° | −0.01 | |
| 37 | Arcturus | α Bootis Boötes Boötes is a constellation in the northern sky, located between 0° and +60° declination, and 13 and 16 hours of right ascension on the celestial sphere. The name comes from the Greek Βοώτης, Boōtēs, meaning herdsman or plowman... |
the bear's guard | 146 | N 19° | −0.04 var | |
| 39 | Zubenelgenubi Alpha Librae Alpha Librae is the second brightest star in the constellation Libra . It has the traditional name Zubenelgenubi. The name, from Arabic الزبن الجنوبي , means "southern claw" and was coined before Libra was recognized as distinct from Scorpius... |
α Librae Libra (constellation) Libra is a constellation of the zodiac. Its name is Latin for weighing scales, and its symbol is . It is fairly faint, with no first magnitude stars, and lies between Virgo to the west and Scorpius to the east.-Notable features:]... |
southern claw (of the scorpion Scorpius Scorpius, sometimes known as Scorpio, is one of the constellations of the zodiac. Its name is Latin for scorpion, and its symbol is . It lies between Libra to the west and Sagittarius to the east... ) |
138 | S 16° | 3.28 | |
| 40 | Kochab Beta Ursae Minoris Beta Ursae Minoris is the second brightest star in the bowl of the "Little Dipper,"the constellation Ursa Minor. It has the traditional name Kochab. Kochab's magnitude is 2.07. It is 16 degrees from Polaris. The star is an orange giant and is 126.4 ± 2.5 light years from Earth. It is 130 times... |
β Ursae Minoris Ursa Minor Ursa Minor , also known as the Little Bear, is a constellation in the northern sky. Like the Great Bear, the tail of the Little Bear may also be seen as the handle of a ladle, whence the name Little Dipper... |
shortened form of "north star" (named when it was that,For more information, see the article changing pole stars. ca. 1500 BC – AD 300). | 137 | N 74° | 2.08 | |
| 41 | Alphecca | α Corona Borealis Corona Borealis Corona Borealis is a small constellation in the northern sky. Its name is Latin for "northern crown", a name inspired by its shape; its main stars form a semicircular arc. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy and remains one of the 88 modern... |
feeble one (in the crown Corona Borealis Corona Borealis is a small constellation in the northern sky. Its name is Latin for "northern crown", a name inspired by its shape; its main stars form a semicircular arc. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy and remains one of the 88 modern... ) |
127 | N 27° | 2.24 | |
| 42 | Antares Antares Antares is a red supergiant star in the Milky Way galaxy and the sixteenth brightest star in the nighttime sky . Along with Aldebaran, Spica, and Regulus it is one of the four brightest stars near the ecliptic... |
α Scorpii Scorpius Scorpius, sometimes known as Scorpio, is one of the constellations of the zodiac. Its name is Latin for scorpion, and its symbol is . It lies between Libra to the west and Sagittarius to the east... |
rival of Mars Mars Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance... (in color) |
113 | S 26° | 1.09 | |
| 43 | Atria Alpha Trianguli Australis Alpha Trianguli Australis is a star in the constellation Triangulum Australe.... |
α Trianguli Australis Triangulum Australe Triangulum Australe is a small constellation in the southern sky, created in the sixteenth century. Its name is Latin for 'the southern triangle', which distinguishes it from Triangulum in the northern sky... |
coined from Bayer name | 108 | S 69° | 1.92 | |
| 44 | Sabik Eta Ophiuchi Eta Ophiuchi, also known as η Oph or η Ophiuchi, is a star in the constellation Ophiuchus. It also has the traditional name Sabik.... |
η Ophiuchi Ophiuchus Ophiuchus is a large constellation located around the celestial equator. Its name is from the Greek "serpent-bearer", and it is commonly represented as a man grasping the snake that is represented by the constellation Serpens. Ophiuchus was one of the 48 constellations listed by the 2nd-century... |
second winner or conqueror | 103 | S 16° | 2.43 | |
| 45 | Shaula Lambda Scorpii Lambda Scorpii is the second brightest star system in the constellation Scorpius, and one of the brightest stars in the nighttime sky. It has the Bayer designation λ despite being the second brightest in its constellation... |
λ Scorpii Scorpius Scorpius, sometimes known as Scorpio, is one of the constellations of the zodiac. Its name is Latin for scorpion, and its symbol is . It lies between Libra to the west and Sagittarius to the east... |
cocked-up part of the scorpion Scorpius Scorpius, sometimes known as Scorpio, is one of the constellations of the zodiac. Its name is Latin for scorpion, and its symbol is . It lies between Libra to the west and Sagittarius to the east... 's tail |
097 | S 37° | 1.62 | |
| 46 | Rasalhague Alpha Ophiuchi Alpha Ophiuchi is the brightest star in the constellation Ophiuchus. It has the traditional name Ras Alhague, often condensed to Rasalhague.... |
α Ophiuchi Ophiuchus Ophiuchus is a large constellation located around the celestial equator. Its name is from the Greek "serpent-bearer", and it is commonly represented as a man grasping the snake that is represented by the constellation Serpens. Ophiuchus was one of the 48 constellations listed by the 2nd-century... |
head of the serpent charmer Ophiuchus Ophiuchus is a large constellation located around the celestial equator. Its name is from the Greek "serpent-bearer", and it is commonly represented as a man grasping the snake that is represented by the constellation Serpens. Ophiuchus was one of the 48 constellations listed by the 2nd-century... |
096 | N 13° | 2.10 | |
| 47 | Eltanin | γ Draconis Draco (constellation) Draco is a constellation in the far northern sky. Its name is Latin for dragon. Draco is circumpolar for many observers in the northern hemisphere... |
head of the dragon Draco (constellation) Draco is a constellation in the far northern sky. Its name is Latin for dragon. Draco is circumpolar for many observers in the northern hemisphere... |
091 | N 51° | 2.23 | |
| 48 | Kaus Australis Epsilon Sagittarii Epsilon Sagittarii is a binary star that lies 144.64 light-years distant in the constellation Sagittarius. It has a faint, 14th magnitude, companion, Epsilon Sagittarii B, 32 arcseconds distant.... |
ε Sagittarii Sagittarius (constellation) Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow... |
southern part of the bow (of Sagittarius Sagittarius (constellation) Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow... ) |
084 | S 34° | 1.80 | |
| 49 | Vega Vega Vega is the brightest star in the constellation Lyra, the fifth brightest star in the night sky and the second brightest star in the northern celestial hemisphere, after Arcturus... |
α Lyra Lyra Lyra is a small constellation. It is one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations recognized by the International Astronomical Union. Its principal star, Vega — a corner of the Summer Triangle — is one of the brightest... e |
the falling eagle or vulture | 081 | N 39° | 0.03 | |
| 50 | Nunki Sigma Sagittarii Sigma Sagittarii is the second brightest star system in the constellation Sagittarius.Its modern name Nunki is an Assyrian or Babylonian name recovered by archaeologists and made public by R.H.Allen.... |
σ Sagittarii Sagittarius (constellation) Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow... |
constellation of the holy city (Eridu Eridu Eridu is an ancient Sumerian city in what is now Tell Abu Shahrain, Dhi Qar Governorate, Iraq. Eridu was considered the earliest city in southern Mesopotamia, and is one of the oldest cities in the world... ) |
076 | S 26° | 2.06 | |
| 51 | Altair | α Aquilae Aquila (constellation) Aquila is a stellar constellation. Its name is Latin for 'eagle' and it is commonly represented as such. In mythology, Aquila was owned by the Roman god Jupiter and performed many tasks for him.... |
flying eagle or vulture | 063 | N 09° | 0.77 | |
| 52 | Peacock Alpha Pavonis Alpha Pavonis is a star in the constellation Pavo. It is also known by the name Peacock, which was assigned by Her Majesty's Nautical Almanac Office in the late 1930s during the creation of the Air Almanac, a navigational almanac for the Royal Air Force... |
α Pavonis Pavo (constellation) Pavo is a constellation in the southern sky. Its name is Latin for peacock. It is one of twelve constellations created by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman and it first appeared on a 35-cm diameter celestial globe published in 1597 in... |
Coined from the English name of the constellation | 054 | S 57° | 1.91 | |
| 53 | Deneb Deneb Deneb is the brightest star in the constellation Cygnus and one of the vertices of the Summer Triangle. It is the 19th brightest star in the night sky, with an apparent magnitude of 1.25. A blue-white supergiant, Deneb is also one of the most luminous nearby stars... |
α Cygnus Cygnus (constellation) Cygnus is a northern constellation lying on the plane of the Milky Way. Its name is the Latinized Hellenic word for swan. One of the most recognizable constellations of the northern summer and autumn, it features a prominent asterism known as the Northern Cross... |
tail of the hen Cygnus (constellation) Cygnus is a northern constellation lying on the plane of the Milky Way. Its name is the Latinized Hellenic word for swan. One of the most recognizable constellations of the northern summer and autumn, it features a prominent asterism known as the Northern Cross... |
050 | N 45° | 1.25 | |
| 54 | Enif | ε Pegasi Pegasus (constellation) Pegasus is a constellation in the northern sky, named after the winged horse Pegasus in Greek mythology. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations.-Stars:... |
nose of the horse Pegasus (constellation) Pegasus is a constellation in the northern sky, named after the winged horse Pegasus in Greek mythology. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations.-Stars:... |
034 | N 10° | 2.40 | |
| 55 | Al Na'ir Alpha Gruis Alpha Gruis is the brightest star in the constellation Grus.Alpha Gruis has a proper name Alnair or Al Nair , came from the Arabic al-nayyir [an-nai:r], meaning "the bright one"... |
α Gruis Grus (constellation) Grus is a constellation in the southern sky. Its name is Latin for the crane, a species of bird. It was introduced in the late sixteenth century.-History:The stars that form Grus were originally considered part of Piscis Austrinus... |
bright one (of the fish Piscis Austrinus Piscis Austrinus is a constellation in the southern celestial hemisphere. The name is Latin for "the southern fish" in contrast with the larger constellation Pisces, which represents a pair of fishes. Prior to the 20th century, it was also known as Piscis Notius... 's tail) |
028 | S 47° | 1.74 | |
| 56 | Fomalhaut Fomalhaut Fomalhaut is the brightest star in the constellation Piscis Austrinus and one of the brightest stars in the sky. Fomalhaut can be seen low in the southern sky in the northern hemisphere in fall and early winter evenings. Near latitude 50˚N, it sets around the time Sirius rises, and does not... |
α Piscis Austrinus Piscis Austrinus Piscis Austrinus is a constellation in the southern celestial hemisphere. The name is Latin for "the southern fish" in contrast with the larger constellation Pisces, which represents a pair of fishes. Prior to the 20th century, it was also known as Piscis Notius... |
mouth of the southern fish Piscis Austrinus Piscis Austrinus is a constellation in the southern celestial hemisphere. The name is Latin for "the southern fish" in contrast with the larger constellation Pisces, which represents a pair of fishes. Prior to the 20th century, it was also known as Piscis Notius... |
016 | S 30° | 1.16 | |
| 57 | Markab Alpha Pegasi Alpha Pegasi is the third brightest star in the constellation Pegasus and one of the four stars in the asterism known as the Great Square of Pegasus. It has the traditional name Markab .Markab is a relatively average star nearing the end of its stellar evolution on the main sequence... |
α Pegasi Pegasus (constellation) Pegasus is a constellation in the northern sky, named after the winged horse Pegasus in Greek mythology. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations.-Stars:... |
saddle (of Pegasus Pegasus (constellation) Pegasus is a constellation in the northern sky, named after the winged horse Pegasus in Greek mythology. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations.-Stars:... ) |
014 | N 15° | 2.49 | |
| * | Polaris Polaris Polaris |Alpha]] Ursae Minoris, commonly North Star or Pole Star, also Lodestar) is the brightest star in the constellation Ursa Minor. It is very close to the north celestial pole, making it the current northern pole star.... |
α Ursae Minoris Ursa Minor Ursa Minor , also known as the Little Bear, is a constellation in the northern sky. Like the Great Bear, the tail of the Little Bear may also be seen as the handle of a ladle, whence the name Little Dipper... |
the pole (star) | 319 | N 89° | 2.01 varThe suffix var after the numeric value denotes a variable star Variable star A star is classified as variable if its apparent magnitude as seen from Earth changes over time, whether the changes are due to variations in the star's actual luminosity, or to variations in the amount of the star's light that is blocked from reaching Earth... whose magnitude changes over time. |
Star charts
| Key to the Star charts | |
|---|---|
| Item | Description |
| UPPERCASE TEXT | Constellation names are indicated in uppercase text. |
| Selected star of magnitude 1.5 and brighter. Labeled with common name, star number, and Greek letter to indicate Bayer designation. | |
| Selected star of magnitude 1.6 and fainter. Labeled with common name, star number, and Greek letter to indicate Bayer designation. | |
| Tabulated star of magnitude 2.5 and brighter. Labeled with Greek letter to indicate Bayer designation. | |
| Tabulated star of magnitude 2.6 and fainter. Labeled with Greek letter to indicate Bayer designation. | |
| Untabulated star. Not labeled. | |
| Dotted line | Constellation outline. |
Navigators often use star charts to identify a star by its position relative to other stars. References like the Nautical Almanac and The American Practical Navigator provide four star charts, covering different portions of the celestial sphere. Two of these charts are azimuthal equidistant projection
Azimuthal equidistant projection
The azimuthal equidistant projection is a type of map projection.A useful application for this type of projection is a polar projection in which all distances measured from the center of the map along any longitudinal line are accurate; an example of a polar azimuthal equidistant projection can be...
s of the north and south poles. The other two cover the equatorial region of the celestial sphere, from the declination of 30° south to 30° north. The two equatorial charts are mercator projection
Mercator projection
The Mercator projection is a cylindrical map projection presented by the Belgian geographer and cartographer Gerardus Mercator, in 1569. It became the standard map projection for nautical purposes because of its ability to represent lines of constant course, known as rhumb lines or loxodromes, as...
s, one for the eastern hemisphere of the celestial sphere and one for the western hemisphere. Note that unlike familiar maps, east is shown to the left and west is shown to the right. With this orientation, the navigator can hold the star chart overhead, and the arrangement of the stars on the chart will resemble the stars in the sky.
In the star charts, constellations are labelled with capital letters and indicated by dotted lines collecting their stars. The 58 selected stars for navigation are shown in blue and labelled with their common name, star number, and a Greek letter to indicate their Bayer designation. The additional 115 tabulated stars that can also be used for navigation are shown in red and labelled with a Greek letter to indicate their Bayer designation. Some additional stars not suitable for navigation are also included on the charts to indicate constellations, they are presented as unlabelled small red dots.
Equatorial stars
Equatorial stars of the eastern hemisphereThe equatorial region of the celestial sphere's eastern hemisphere includes 16 navigational stars from Alpheratz in the constellation Andromeda to Denebola in Leo. It also includes stars from the constellations Cetus, Aries, Taurus, Orion, Canis Major and Minor, Gemini, and Hydra. Of particular note among these stars are "the dog star" Sirius, the brightest star in the sky, and four stars of the easily identified constellation Orion.
Image:Bowditch-equatorial-stars-180-360.svg|center|600px|alt=Equatorial stars with SHA from 180 to 360|
rect 767 236 803 264 Diphda (#4) SHA 349 Dec. S 18
rect 672 37 708 71 Hamal (#6) SHA 328 Dec. N 23
rect 616 134 657 178 Menkar (#8) SHA 315 Dec. N 04
rect 513 72 544 106 Aldebaran (#10) SHA 291 Dec. N 16
rect 474 192 508 225 Rigel (#11) SHA 282 Dec. S 08
rect 466 124 491 154 Bellatrix (#13) SHA 279 Dec. N 06
rect 460 18 486 45 Elnath (#14) SHA 279 Dec. N 29
rect 454 162 472 184 Alnilam (#15) SHA 276 Dec. S 01
rect 416 108 461 159 Betelgeuse (#16) SHA 271 Dec. N 07
rect 375 228 407 266 Sirius (#18) SHA 259 Dec. S 17
rect 363 293 397 320 Adhara (#19) SHA 256 Dec. S 29
rect 313 130 352 165 Procyon (#20) SHA 245 Dec. N 05
rect 304 21 347 54 Pollux (#21) SHA 244 Dec. N 28
rect 199 195 232 232 Alphard (#25) SHA 218 Dec. S 09
rect 803 13 840 46 Alpheratz (#1) SHA 358 Dec. N 29
rect 154 95 192 135 Regulus (#26) SHA 208 Dec. N 12
rect 46 81 77 121 Denebola (#28) SHA 183 Dec. N 15
desc top-right
Equatorial stars of the western hemisphere
The equatorial region of the celestial sphere's western hemisphere includes 13 navigational stars from Gienah in the constellation Corvus to Markab in Pegasus. It also includes stars from the constellations Virgo, Bootes, Libra, Corona Borealis, Scorpio, Ophiuchus, Sagittarius, and Aquila. The variable star
Variable star
A star is classified as variable if its apparent magnitude as seen from Earth changes over time, whether the changes are due to variations in the star's actual luminosity, or to variations in the amount of the star's light that is blocked from reaching Earth...
Arcturus is the brightest star in this group.
Image:Bowditch-equatorial-stars-0-180.svg|center|600px|alt=Equatorial stars with SHA from 0 to 180|
rect 812 240 829 265 Geinah (#29) SHA 165 Dec. S 19
rect 731 206 760 236 Spica (#33) SHA 159 Dec. S 11
rect 673 63 707 105 Arcturus (#37) SHA 146 Dec. N 19
rect 634 228 665 262 Zubenelgenubi (#39) SHA 138 Dec. S 16
rect 587 27 627 62 Alphecca (#41) SHA 127 Dec. N 27
rect 525 279 558 309 Antares (#42) SHA 113 Dec. S 26
rect 477 228 513 259 Sabik (#44) SHA 103 Dec. S 16
rect 456 92 489 124 Rasalhague (#46) SHA 096 Dec. N 13
rect 364 277 400 309 Nunki (#50) SHA 076 Dec. S 26
rect 306 106 335 149 Altair (#51) SHA 063 Dec. N 19
rect 186 111 229 147 Enif (#54) SHA 034 Dec. N 10
rect 103 293 139 325 Fomalhaut (#56) SHA 016 Dec. S 30
rect 99 80 132 117 Markab (#57) SHA 014 Dec. N 15
rect 23 19 65 52 Alpheratz (#1) SHA 358 Dec. N 29
desc top-right
Northern stars
Image:Navigational-stars-above-30-degrees-north.svg|float|right|400px|alt=Northern navigational stars|
rect 93 183 121 212 Schedar (#3) SHA 350 Dec. N 56
rect 119 104 150 135 Mirfac (#9) SHA 309 Dec. N 50
rect 172 63 211 103 Capella (#12) SHA 281 Dec. N 46
rect 282 177 315 220 Dubhe (#27) SHA 194 Dec. N 62
rect 306 230 337 259 Alioth (#32) SHA 167 Dec. N 56
rect 315 267 345 297 Alkaid (#34) SHA 153 Dec. N 49
rect 240 243 269 267 Kochab (#40) SHA 137 Dec. N 74
rect 202 332 233 364 Eltanin (#47) SHA 091 Dec. N 51
rect 179 366 203 398 Vega (#49) SHA 081 Dec. N 39
rect 110 314 136 349 Deneb (#53) SHA 050 Dec. N 45
rect 198 199 230 235 Polaris SHA 319 Dec. N 89
desc top-right
The 11 northern stars are those with a declination between 30° north and 90° north. They are listed in order of decreasing sidereal hour angle, or from the vernal equinox westward across the sky. Starting with Schedar in the Cassiopeia constellation, the list includes stars from the constellations Auriga, the Great and Little Bears, Draco, Lyra and Cygnus. The two brightest northern stars are Vega and Capella.
In the star chart to the right, declination is shown by the radial coordinate, starting at 90° north in the center and decreasing to 30° north at the outer edge. Sidereal hour angle is shown as the angular coordinate, starting at 0° at the left of the chart, and increasing counter-clockwise.
Southern stars
Image:Navigational-stars-below-30-degrees-south.svg|float|right|400px|alt=Southern navigational stars|
rect 351 191 379 218 Ankaa (#2) SHA 354 Dec. S 42
rect 297 158 322 192 Achernar (#5) SHA 336 Dec. S 57
rect 311 94 341 121 Acamar (#7) SHA 316 Dec. S 40
rect 191 85 223 119 Canopus (#17) SHA 264 Dec. S 53
rect 146 129 171 156 Avior (#22) SHA 234 Dec. S 59
rect 92 105 123 135 Suhail (#23) SHA 223 Dec. S 43
rect 155 166 189 193 Miaplacidus (#24) SHA 222 Dec. S 70
rect 123 222 145 251 Acrux (#30) SHA 174 Dec. S 63
rect 102 227 120 247 Gacrux (#31) SHA 172 Dec. S 57
rect 122 262 146 280 Hadar (#35) SHA 149 Dec. S 60
rect 60 302 83 330 Menkent (#36) SHA 149 Dec. S 60
rect 135 278 158 299 Rigel Kentaurus (#38) SHA 140 Dec. S 61
rect 183 272 206 304 Atria (#43) SHA 108 Dec. S 69
rect 194 381 215 405 Shaula (#45) SHA 097 Dec. S 34
rect 224 394 249 416 Kaus Australis (#48) SHA 084 Dec. S 34
rect 268 299 292 321 Peacock (#52) SHA 054 Dec. S 57
rect 322 278 347 304 Al Na'ir (#55) SHA 028 Dec S 47
rect 385 262 414 286 Fomalhaut (#56) SHA 016 Dec. S 30
desc top-right
The 18 southern stars are those with a declination between 30° south and 90° south. They are listed in order of decreasing sidereal hour angle, or from the vernal equinox westward across the sky. Starting with Ankaa in the Phoenix constellation, the list includes stars from the constellations Eridanus, Carina, Crux, Centaurus, Libra, Triangulum Australe, Scorpio, Sagittarius, Pavo, and Grus. Canopus, Rigil Kentaurus, Achernar, and Hadar are the brightest stars in the southern sky.
In the star chart to the right, declination is shown by the radial coordinate, starting at 90° north in the center and decreasing to 30° north at the outer edge. Sidereal hour angle is shown as the angular coordinate, starting at 0° at the right of the chart, and increasing clockwise.