HD 5319
Encyclopedia
HD 5319 is an 8th magnitude
star
approximately 326 light years away in the constellation
Cetus
. It is a giant star
of spectral type K0, having run out of hydrogen
in its core. When it was main-sequence, the spectral type was early F or late A.
The radius is more than three times that of the Sun, and the volume is 35 times greater. The star's mass is more than 1.5 times that of the Sun
, which suggests much lower density.
The absolute magnitude
(apparent magnitude at 10 parsecs) is 3.05, which would translate to easy naked eye visibility, but its distance is ten times greater, so its apparent magnitude
is 8.05 (100 times fainter than its absolute magnitude), it is not visible to the naked eye
and binoculars
are needed.
orbiting the giant star. It was published in the December 1, 2007 edition of the Astrophysical Journal
.
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...
star
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...
approximately 326 light years away in 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....
Cetus
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...
. It is a giant star
Giant star
A giant star is a star with substantially larger radius and luminosity than a main sequence star of the same surface temperature. Typically, giant stars have radii between 10 and 100 solar radii and luminosities between 10 and 1,000 times that of the Sun. Stars still more luminous than giants are...
of spectral type K0, having run out of hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
in its core. When it was main-sequence, the spectral type was early F or late A.
The radius is more than three times that of the Sun, and the volume is 35 times greater. The star's mass is more than 1.5 times that of the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
, which suggests much lower density.
The absolute magnitude
Absolute magnitude
Absolute magnitude is the measure of a celestial object's intrinsic brightness. it is also the apparent magnitude a star would have if it were 32.6 light years away from Earth...
(apparent magnitude at 10 parsecs) is 3.05, which would translate to easy naked eye visibility, but its distance is ten times greater, so its 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...
is 8.05 (100 times fainter than its absolute magnitude), it is not visible to the naked eye
Naked eye
The naked eye is a figure of speech referring to human visual perception unaided by a magnifying or light-collecting optical device, such as a telescope or microscope. Vision corrected to normal acuity using corrective lenses is considered "naked"...
and binoculars
Binoculars
Binoculars, field glasses or binocular telescopes are a pair of identical or mirror-symmetrical telescopes mounted side-by-side and aligned to point accurately in the same direction, allowing the viewer to use both eyes when viewing distant objects...
are needed.
Planetary system
On January 11, 2007, the California and Carnegie Planet Search team found a 1.94 MJ extrasolar planetExtrasolar planet
An 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...
orbiting the giant star. It was published in the December 1, 2007 edition of the Astrophysical Journal
Astrophysical Journal
The Astrophysical Journal is a peer-reviewed scientific journal covering astronomy and astrophysics. It was founded in 1895 by the American astronomers George Ellery Hale and James Edward Keeler. It publishes three 500-page issues per month....
.