| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Cancer |
| Right ascension | 08h 33m 00.104s[1] |
| Declination | +24° 05′ 05.26″[1] |
| Apparent magnitude (V) | +6.35[2] |
| Characteristics | |
| Spectral type | G9 III[3] |
| U−B color index | +0.88[2] |
| B−V color index | +1.02[2] |
| Astrometry | |
| Radial velocity (Rv) | +73.7±0.5[4] km/s |
| Proper motion (μ) | RA: −63.482 mas/yr[1] Dec.: −46.082 mas/yr[1] |
| Parallax (π) | 5.251±0.025 mas[1] |
| Distance | 621 ± 3 ly (190.4 ± 0.9 pc) |
| Absolute magnitude (MV) | +1.13[3] |
| Details | |
| Mass | 3.50±0.04[1] M☉ |
| Radius | 15.18+0.31 −0.27[1] R☉ |
| Luminosity | 110±1[1] L☉ |
| Surface gravity (log g) | 2.43±0.11[5] cgs |
| Temperature | 4,881±44[5] K |
| Metallicity [Fe/H] | 0.00±0.05[5] dex |
| Rotational velocity (v sin i) | 2.7[6] km/s |
| Age | 250+24 −23[1] Myr |
| Other designations | |
| υ2 Cnc, 32 Cancri, BD+24°1946, HD 72324, HIP 41940, HR 3369, SAO 80245[7] | |
| Database references | |
| SIMBAD | data |
Upsilon2 Cancri is a yellow-hued star in the zodiac constellation of Cancer. Its name is a Bayer designation that is Latinized from υ2 Cancri, and abbreviated Upsilon2 Cnc or υ2 Cnc. This star is near the lower brightness limit of stars that can be viewed with the naked eye, having an apparent visual magnitude of +6.35.[2] Based upon an annual parallax shift of 5.1325 mas as seen from Earth's orbit,[1] this system is approximately 621 light-years (190 pc) away. It is drifting further from the Sun with a line of sight velocity of +74 km/s.[4] The position of this star near the ecliptic means it is subject to lunar occultation.[8]
At an age of 250 million years,[1] this is an evolved G-type giant star with a stellar classification of G9 III.[3] It has 3.5 times the mass of the Sun but has expanded to 15 times the Sun's radius.[1] The star is radiating 110[1] times the Sun's luminosity from its swollen photosphere at an effective temperature of 4,881 K.[5] It is spinning with a projected rotational velocity of 2.7 km/s.[6] Upsilon2 Cancri is a member of the Epsilon Indi Moving Group of stars that share a common motion through space.[3]
References
[edit]- ^ a b c d e f g h i j k l Vallenari, A.; et al. (Gaia collaboration) (2023), "Gaia Data Release 3. Summary of the content and survey properties", Astronomy and Astrophysics, 674: A1, arXiv:2208.00211, Bibcode:2023A&A...674A...1G, doi:10.1051/0004-6361/202243940, S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c d Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
- ^ a b c d Eggen, O. J. (1958), "Stellar groups. II. The ζ Herculis, ε Indi and 61 Cygni groups of high-velocity stars", Monthly Notices of the Royal Astronomical Society, 118 (2): 154, Bibcode:1958MNRAS.118..154E, doi:10.1093/mnras/118.2.154.
- ^ a b de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
- ^ a b c d Prugniel, Ph.; et al. (2011), "The atmospheric parameters and spectral interpolator for the MILES stars", Astronomy & Astrophysics, 531: A165, arXiv:1104.4952, Bibcode:2011A&A...531A.165P, doi:10.1051/0004-6361/201116769, S2CID 54940439.
- ^ a b De Medeiros, J. R.; et al. (November 2000), "Rotation and lithium in single giant stars", Astronomy and Astrophysics, 363: 239–243, arXiv:astro-ph/0010273, Bibcode:2000A&A...363..239D.
- ^ "ups02 Cnc", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2017-06-10.
- ^ Schmidtke, P. C.; Africano, J. L. (2011), "KPNO Lunar Occultation Summary. III", The Astronomical Journal, 141 (1): 10, Bibcode:2011AJ....141...10S, doi:10.1088/0004-6256/141/1/10.
