Lacerta
Encyclopedia
Lacerta is one of the 88 modern constellation
s defined by the International Astronomical Union
. Its name is Latin
for lizard
. A small, faint constellation, it was created in 1687 by the astronomer Johannes Hevelius
. Its brightest stars form a "W" shape similar to that of Cassiopeia
, and it is thus sometimes referred to as 'Little Cassiopeia'. It is located between Cygnus
, Cassiopeia and Andromeda
on the northern celestial sphere
. The northern part lies on the Milky Way
.
constellations: no bright galaxies
, nor globular cluster
s, but instead open cluster
s, for example NGC 7243
, the faint planetary nebula
IC 5271 and quite a few double star
s. It also contains the prototypic blazar
BL Lacertae
.
Lacerta contains no Messier
objects
.
'es creation of the constellation, this area, including the "rock of" Andromeda
, was assembled by Royer
to
form the constellation Sceptrum et Manus Iustitiae
. Later, when Lacerta sive Stellio was established, Bode
created the constellation Frederici Honores
for the dropped "rock of" Andromeda part. Both Sceptrum et Manus Iustitiae and Frederici Honores are now obsolete
and not used by astronomers, while Lacerta still survives.
call this part of the sky 'Lizard' and include it in multiple stories.
was an attack cargo ship in the United States navy named after the 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 defined by the International Astronomical Union
International Astronomical Union
The International Astronomical Union IAU is a collection of professional astronomers, at the Ph.D. level and beyond, active in professional research and education in astronomy...
. Its name is Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
for lizard
Lizard
Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...
. A small, faint constellation, it was created in 1687 by the astronomer Johannes Hevelius
Johannes Hevelius
Johannes Hevelius Some sources refer to Hevelius as Polish:Some sources refer to Hevelius as German:*Encyplopedia Britannica * of the Royal Society was a councilor and mayor of Danzig , Pomeranian Voivodeship, in the Polish-Lithuanian Commonwealth...
. Its brightest stars form a "W" shape similar to that 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...
, and it is thus sometimes referred to as 'Little Cassiopeia'. It is located between 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...
, Cassiopeia and Andromeda
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...
on the northern 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...
. The northern part lies on the Milky Way
Milky Way
The Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky...
.
Notable features
Lacerta is typical of Milky WayMilky Way
The Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky...
constellations: no bright galaxies
Galaxy
A galaxy is a massive, gravitationally bound system that consists of stars and stellar remnants, an interstellar medium of gas and dust, and an important but poorly understood component tentatively dubbed dark matter. The word galaxy is derived from the Greek galaxias , literally "milky", a...
, nor globular cluster
Globular cluster
A globular cluster is a spherical collection of stars that orbits a galactic core as a satellite. Globular clusters are very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their centers. The name of this category of star cluster is...
s, but instead open cluster
Open cluster
An open cluster is a group of up to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way Galaxy, and many more are thought to exist...
s, for example NGC 7243
NGC 7243
NGC 7243, also Caldwell 16, is an open cluster and Caldwell object in the constellation Lacerta. It shines at magnitude +6.4. Its celestial coordinates are RA , dec . It is located near the naked-eye stars Alpha Lacertae, 4 Lacertae, an A-class double star, and planetary nebula IC 5217...
, the faint planetary nebula
Planetary nebula
A planetary nebula is an emission nebula consisting of an expanding glowing shell of ionized gas ejected during the asymptotic giant branch phase of certain types of stars late in their life...
IC 5271 and quite a few double star
Double star
In observational astronomy, a double star is a pair of stars that appear close to each other in the sky as seen from Earth when viewed through an optical telescope. This can happen either because the pair forms a binary star, i.e...
s. It also contains the prototypic blazar
Blazar
A blazar is a very compact quasar associated with a presumed supermassive black hole at the center of an active, giant elliptical galaxy...
BL Lacertae
BL Lacertae
BL Lacertae or BL Lac is a highly variable, extragalactic AGN . It was first discovered by Cuno Hoffmeister in 1929, but was originally thought to be an irregular variable star in the Milky Way galaxy and so was given a variable star designation...
.
Lacerta contains no Messier
Charles Messier
Charles Messier was a French astronomer most notable for publishing an astronomical catalogue consisting of deep sky objects such as nebulae and star clusters that came to be known as the 110 "Messier objects"...
objects
Messier object
The Messier objects are a set of astronomical objects first listed by French astronomer Charles Messier in 1771. The original motivation of the catalogue was that Messier was a comet hunter, and was frustrated by objects which resembled but were not comets...
.
Stars
- α LacAlpha LacertaeAlpha Lacertae is an A-type main sequence star in the constellation of Lacerta...
: this main sequenceMain sequenceThe main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell...
star of spectral typeStellar classificationIn astronomy, stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are most prominent in the light, giving an objective measure...
A1 V has an apparent magnitudeApparent magnitudeThe 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 merely 3.77; Lacerta has no other stars brighter than fourth magnitude. α Lac is an optical double starDouble starIn observational astronomy, a double star is a pair of stars that appear close to each other in the sky as seen from Earth when viewed through an optical telescope. This can happen either because the pair forms a binary star, i.e...
. - Roe 47: a multiple star consisting of five components (magnitudes 5.8, 9.8, 10.1, 9.4, 9.8).
- ADS 16402ADS 16402ADS 16402 is a binary star system, composed of two sun-like stars located 450 light-years away in the constellation Lacerta. The two stars are separated by 1500 AUs. The star system is estimated to be 3.6 billion years old...
is a binary starBinary starA binary star is a star system consisting of two stars orbiting around their common center of mass. The brighter star is called the primary and the other is its companion star, comes, or secondary...
system in Lacerta, around which a planetExtrasolar planetAn extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of such planets have been identified as of . It is now known that a substantial fraction of stars have planets, including perhaps half of all Sun-like stars...
orbits with some unusual properties. The JupiterJupiterJupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...
-sized planet exhibits an unexpectedly low density, about the same as cork. This planet is dubbed HAT P-1.
Deep sky objects
- NGC 7243NGC 7243NGC 7243, also Caldwell 16, is an open cluster and Caldwell object in the constellation Lacerta. It shines at magnitude +6.4. Its celestial coordinates are RA , dec . It is located near the naked-eye stars Alpha Lacertae, 4 Lacertae, an A-class double star, and planetary nebula IC 5217...
: an open star clusterOpen clusterAn open cluster is a group of up to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way Galaxy, and many more are thought to exist...
of approximately 6.4m. - BL LacertaeBL LacertaeBL Lacertae or BL Lac is a highly variable, extragalactic AGN . It was first discovered by Cuno Hoffmeister in 1929, but was originally thought to be an irregular variable star in the Milky Way galaxy and so was given a variable star designation...
: it was discovered quite early and first thought to be a star and therefore given a variable star designationVariable star designationVariable stars are named using a variation on the Bayer designation format of an identifying label combined with the Latin genitive of the name of the constellation in which the star lies...
. However, in reality it is the core of a galaxy. It lent its name to a whole type of celestial objects, the BL Lacertae objects (a subtype of blazarBlazarA blazar is a very compact quasar associated with a presumed supermassive black hole at the center of an active, giant elliptical galaxy...
.) The object varies irregularly between magnitudes 14 and 17 over a few days.
History
Centred on a region of the sky without apparently bright stars, Lacerta was not regarded as a constellation by ancient astronomers. Before Johannes HeveliusJohannes Hevelius
Johannes Hevelius Some sources refer to Hevelius as Polish:Some sources refer to Hevelius as German:*Encyplopedia Britannica * of the Royal Society was a councilor and mayor of Danzig , Pomeranian Voivodeship, in the Polish-Lithuanian Commonwealth...
'es creation of the constellation, this area, including the "rock of" Andromeda
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...
, was assembled by Royer
Augustin Royer
Augustin Royer was a French architect who lived in the time of Louis XIV.In 1679 he published a star map; in addition to the 48 constellations of Ptolemy, and the additions of more recent astronomers such as Plancius, he added two constellations of his own, in honour of his patron, Louis XIV;...
to
form the constellation Sceptrum et Manus Iustitiae
Sceptrum et Manus Iustitiae
Sceptrum et Manus Iustitiae was a constellation created by Augustin Royer in 1679 to honor king Louis XIV of France...
. Later, when Lacerta sive Stellio was established, Bode
Johann Elert Bode
Johann Elert Bode was a German astronomer known for his reformulation and popularization of the Titius-Bode law. Bode determined the orbit of Uranus and suggested the planet's name.-Biography:...
created the constellation Frederici Honores
Frederici Honores
Frederici Honores or Honores Friderici or Gloria Frederica was a constellation created by Johann Bode in 1787 to honor Frederick the Great, the king of Prussia who had died in the previous year. It was located in a region between the constellations Cepheus, Andromeda, Cassiopeia and Cygnus...
for the dropped "rock of" Andromeda part. Both Sceptrum et Manus Iustitiae and Frederici Honores are now obsolete
Former constellations
Former constellations are constellations that are no longer recognized by the International Astronomical Union for various reasons. Many of these constellations existed for long periods of time, even centuries in many cases, which means they still have a large historical value and can be found on...
and not used by astronomers, while Lacerta still survives.
Equivalents
Coincidentally, the Chumash people of CaliforniaCalifornia
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
call this part of the sky 'Lizard' and include it in multiple stories.
Namesakes
USS Lacerta (AKA-29)USS Lacerta (AKA-29)
USS Lacerta was an named after the constellation Lacerta. She served as a commissioned ship for 15 months.Lacerta was laid down under a Maritime Commission contract 5 July 1944 by Walsh-Kaiser Co., Inc., Providence, R.I.; launched 10 November 1944; sponsored by Mrs. Frank Bratley; acquired by...
was an attack cargo ship in the United States navy named after the constellation.
External links
- http://LacertaUSA.com Herpetoculture of Lacertidae
- The Deep Photographic Guide to the Constellations: Lacerta
- Star Tales – Lacerta
- Weasner's Mighty ETX Site, GO TO LACERTA (a constellation guide for amateur astronomers)