Delta Crateris (δ Crt, δ Crateris; traditional name: Labrum) is a solitary[9] star in the southern constellation of Crater. With an apparent visual magnitude of 3.56,[2] it is the brightest star[10] in this rather dim constellation. It has an annual parallax shift of 17.56[1] mas as measured from Earth, indicating Delta Crateris lies at a distance of 163 ± 4 light years from the Sun.
This is an evolved orange-hued giant star belonging to the spectral class K0 III. Delta Crateris is a member of the so-called red clump, indicating that it is generating energy through the thermonuclear fusion of helium at its core.[5] The star has an estimated 1.56[6] times the mass of the Sun but has expanded to 22.44±0.28[7] times the Sun's radius.
The metallicity of the star – what astronomers term the abundance of elements other than hydrogen and helium – is only 33% that of the Sun.[2] It is around 2.89[6] billion years old with a rotation rate that is too small to measure; the projected rotational velocity is 0.0 km/s.[3] Delta Crateris is radiating 171.4±9.0 as much luminosity as the Sun from its outer envelope at an effective temperature of 4,510±15 K.[6]
^ abcdefgMallik, Sushma V. (December 1999), "Lithium abundance and mass", Astronomy and Astrophysics, 352: 495–507, Bibcode:1999A&A...352..495M.
^ abcMassarotti, Alessandro; et al. (January 2008), "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity", The Astronomical Journal, 135 (1): 209–231, Bibcode:2008AJ....135..209M, doi:10.1088/0004-6256/135/1/209, S2CID 121883397.
^"del Crt". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-03-02.{{cite web}}: CS1 maint: postscript (link)
^Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.