Zeta Crateris (ζ Crateris) is a probable binary star system in the southern constellation of Crater. Zeta Crateris appears to be about half-way between Epsilon Corvi to the southeast and

Beta Crateris Beta Crateris, Latinized from β Crateris, is a binary star system in the southern constellation of Crater. It is visible to the naked eye with an apparent visual magnitude of 4.46. Based upon an annual parallax shift of 9.59 mas a ...

to the northwest, and marks the lower left corner of the rim of the bowl.

Eta Crateris Eta Crateris, Latinized from η Crateris, is a solitary star in the southern constellation of Crater. It marks the lip of the tilted bowl on the left side in the constellation. Eta Crateris lies in the sky NE of Zeta Crateris and NN ...

lies somewhat less than half of the way from Zeta Crateris to

Gamma Corvi Gamma Corvi (γ Corvi, abbreviated Gamma Crv, γ Crv) is a binary star and the brightest star in the southern constellation of Corvus, having an apparent visual magnitude of 2.59. The system's two components are designated Gamma Corvi A (of ...

, the bright star above, (north) of Epsilon Corvi. Zeta Crateris is a photometrically constant system that is visible to the naked eye with an

apparent visual magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's lig ...

of 4.740. With an annual parallax shift of 9.24 mas as viewed from Earth, Zeta Crateris is located roughly 350 light years from the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

. At that distance, the visual magnitude of the system is diminished by an extinction factor of 0.21 due to

interstellar dust Cosmic dust, also called extraterrestrial dust, star dust or space dust, is dust which exists in outer space, or has fallen on Earth. Most cosmic dust particles measure between a few molecules and 0.1 mm (100 micrometers). Larger particles are c ...

. The two components of this system had an angular separation of 0.20

arc second A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc is of a turn. The n ...

s along a

position angle In astronomy, position angle (usually abbreviated PA) is the convention for measuring angles on the sky. The International Astronomical Union defines it as the angle measured relative to the north celestial pole (NCP), turning positive into the ...

of 22°, as of 1991. The primary, component A, is a magnitude 4.95

evolved Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...

giant star A giant star is a star with substantially larger radius and luminosity than a main-sequence (or ''dwarf'') star of the same surface temperature.Giant star, entry in ''Astronomy Encyclopedia'', ed. Patrick Moore, New York: Oxford University Press ...

with a stellar classification of G8 III. It is a

red clump Red is the color at the long wavelength end of the visible spectrum of light, next to orange and opposite violet. It has a dominant wavelength of approximately 625–740 nanometres. It is a primary color in the RGB color model and a secondary ...

star that is generating energy through the fusion of helium at its core. Zeta Crateris has expanded to 13 times the

radius of the Sun Solar radius is a unit of distance used to express the size of stars in astronomy relative to the Sun. The solar radius is usually defined as the radius to the layer in the Sun's photosphere where the optical depth equals 2/3: :1\,R_ = 6.957\t ...

and shines with 157 times the

Sun's luminosity The solar luminosity (), is a unit of radiant flux (power emitted in the form of photons) conventionally used by astronomers to measure the luminosity of stars, galaxies and other celestial objects in terms of the output of the Sun. One nominal ...

. This energy is being radiated into outer space from the outer envelope at an effective temperature of 4,992 K. The secondary, component B, is a magnitude 7.84 star. Zeta Crateris is a confirmed member of the

Sirius supercluster Sirius is the brightest star in the night sky. Its name is derived from the Greek word , or , meaning 'glowing' or 'scorching'. The star is designated α Canis Majoris, Latinized to Alpha Canis Majoris, and abbreviated Alpha CMa ...

and is a candidate member of the Ursa Major Moving Group, a collection of stars that share a similar motion through space and may have at one time been members of the same

open cluster An open cluster is a type of star cluster made 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, an ...

References

{{DEFAULTSORT:Zeta Crateris G-type giants Horizontal-branch stars Double stars Ursa Major Moving Group Crater (constellation) Crateris, Zeta Durchmusterung objects Crateris, 27 057283 102070 4514