Phi2 Cancri
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Cancer |
| φ2 Cnc A | |
| Right ascension | 08h 26m 47.07096s[1] |
| Declination | +26° 56′ 07.7588″[1] |
| Apparent magnitude (V) | 6.26[2] |
| φ2 Cnc B | |
| Right ascension | 08h 26m 46.83329s[3] |
| Declination | +26° 56′ 03.6655″[3] |
| Apparent magnitude (V) | 6.31[2] |
| Characteristics | |
| φ2 Cnc A | |
| Spectral type | A6V[2] or A5IV[4] |
| φ2 Cnc B | |
| Spectral type | A3V[2] or A2 Vp(4481 wk)[4] |
| Astrometry | |
| φ2 Cnc A | |
| Proper motion (μ) | RA: −7.487 mas/yr[1] Dec.: +1.202 mas/yr[1] |
| Parallax (π) | 9.4528±0.0351 mas[1] |
| Distance | 345 ± 1 ly (105.8 ± 0.4 pc) |
| φ2 Cnc B | |
| Proper motion (μ) | RA: −10.112 mas/yr[3] Dec.: +0.110 mas/yr[3] |
| Parallax (π) | 9.3703±0.0306 mas[3] |
| Distance | 348 ± 1 ly (106.7 ± 0.3 pc) |
| Details | |
| φ2 Cnc A | |
| Mass | 2.146±0.041[1] M☉ |
| Radius | 3.176±0.067[1] R☉ |
| Luminosity | 32.84+0.42 −0.049[1] L☉ |
| Surface gravity (log g) | 3.689±0.006[1] cgs |
| Temperature | 7,758+26 −41[1] K |
| Rotational velocity (v sin i) | 149[5] km/s |
| Age | 807±102[1] Myr |
| φ2 Cnc B | |
| Mass | 2.643±0.043[3] M☉ |
| Radius | 2.559±0.056[3] R☉ |
| Luminosity | 66±1[3] L☉ |
| Surface gravity (log g) | 3.896+0.024 −0.027[3] cgs |
| Temperature | 7,595+29 −37[3] K |
| Rotational velocity (v sin i) | 133[5] km/s |
| Age | 309±55[3] Myr |
| Other designations | |
| φ2 Cnc, 23 Cancri, BD+27°1612, FK5 2633, HIP 41404[6] | |
| φ2 Cnc A: HD 71151, HR 3311, SAO 80188 | |
| φ2 Cnc B: HD 71150, HR 3310, SAO 80187 | |
| Database references | |
| SIMBAD | φ2 Cnc A |
| φ2 Cnc B | |
Phi2 Cancri is a binary star system in the zodiac constellation of Cancer. Its name is a Bayer designation that is Latinized from φ2 Cancri, and abbreviated Phi2 Cnc or φ2 Cnc. With a combined apparent magnitude of 5.54,[2] this system is faintly visible to the naked eye under ideal conditions. Parallax measurements give a distance of 345–348 light-years to this system. Both components are separated by 5.126 arcseconds on the sky.[2] They were identified as a candidate wide binary system in 1988 based on a low angular separation and similar proper motions.[7]
φ2 Cancri A, of apparent magnitude 6.26, has a spectral type A6V,[2] making it an A-type main sequence star. A 1995 study found a class of A5IV,[4] suggesting it is instead an aging subgiant star. It is about 800[1] million years old and has a high rate of spin, showing a projected rotational velocity of 149 km/s.[5] This star has 2.1 times the mass of the Sun and 3.18 times the Sun's radius. It is radiating 33 times the luminosity of the Sun from its photosphere at an effective temperature of 7,758 K.[1]
φ2 Cancri B, of apparent magnitude 6.31, is also an A-type main sequence star, of spectral type A3V.[2] A 1995 study found this to be a chemically peculiar star with a class of A2 Vp(4481 wk).[4] In addition to displaying evidence of variability, emission lines in the spectrum suggest this is a shell star.[8] It has 2.6 times the Sun's mass and 2.56 times the radius. The star radiates 66 times the Sun's luminosity at an effective temperature of 7,595 K.[3] This star is spinning rapidly with a projected rotational velocity of 133 km/s.[5]
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 e f g h 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.
- ^ a b c d e f g h i j k 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 Abt, Helmut A.; Morrell, Nidia I. (1995), "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars", The Astrophysical Journal Supplement Series, 99: 135–172, Bibcode:1995ApJS...99..135A, doi:10.1086/192182.
- ^ a b c d Royer, F.; et al. (May 2002), "Rotational velocities of A-type stars II. Measurement of vsini in the northern hemisphere", Astronomy & Astrophysics, 393: 897–912, arXiv:astro-ph/0205255, Bibcode:2002A&A...393..897R, doi:10.1051/0004-6361:20020943, S2CID 14070763.
- ^ "* phi02 Cnc", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2017-06-09.
- ^ Weinberg, Martin D.; Wasserman, Ira (June 1988), "Search for Wide Binaries in the Yale Bright Star Catalogue", Astrophysical Journal, 329: 253, Bibcode:1988ApJ...329..253W, doi:10.1086/166375.
- ^ Hauck, B.; Jaschek, C. (February 2000), "A-shell stars in the Geneva system", Astronomy and Astrophysics, 354: 157–162, Bibcode:2000A&A...354..157H.
