| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Taurus |
| Right ascension | 04 30 33.633 |
| Declination | +16° 11′ 38.46″ |
| Apparent magnitude (V) | 4.78 |
| Characteristics | |
| Spectral type | A6 IV or A7 V |
| B−V color index | +0.170±0.001 |
| Variable type | suspected δ Sct |
| Astrometry | |
| Radial velocity (Rv) | +38.1±0.8 km/s |
| Proper motion (μ) | RA: +104.422 mas/yr Dec.: −26.254 mas/yr |
| Parallax (π) | 22.0357 ± 0.2516 mas |
| Distance | 148 ± 2 ly (45.4 ± 0.5 pc) |
| Absolute magnitude (MV) | +1.58 |
| Details | |
| Mass | 1.75 M☉ |
| Radius | 2.209 R☉ |
| Luminosity | 19.03 L☉ |
| Surface gravity (log g) | 4.17±0.14 cgs |
| Temperature | 8,274±281 K |
| Metallicity | +0.30 dex |
| Rotation | 1.278 d |
| Rotational velocity (v sin i) | 87.5 km/s |
| Age | 307 Myr |
| Other designations | |
| NSV 1627, BD+15°637, GJ 170.1/9157, HD 28527, HIP 21029, HR 1427, SAO 93975 | |
| Database references | |
| SIMBAD | data |
HD 28527 is a star in the constellation Taurus, and a member of the Hyades open cluster. It is faintly visible to the naked eye with an apparent visual magnitude of 4.78. The distance to this star, as determined from its parallax shift of 22 mas, is 148 light years. It is moving away from the Earth with a heliocentric radial velocity of +38 km/s.
Based upon a stellar classification of A6 IV by Cowley et al. (1969), this is an A-type subgiant star that has consumed the hydrogen at its core and is evolving away from the main sequence. Older studies had it classed as an A-type main-sequence star with a class of A7 V. At the age of 307 million years, it has a high rate of spin, revolving upon its axis once every 1.278 days. It is a Delta Scuti variable with 1.75 times the mass of the Sun and 2.2 times the Sun's radius. The star is radiating 19 times the Sun's luminosity from its photosphere at an effective temperature of 8,274 K.
Due to its location near the ecliptic, this star is subject to lunar occultations. These events have provided occasional, but not definitive, evidence of a close secondary companion. Eggleton and Tokovinin (2008) catalogue this as a possible triple star system, having the inner pair being similar stars with an angular separation of 0.02″, and the outer component a magnitude 6.7 star of class F2 at a much wider separation of 250″.
See also
References
- ^ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051.
- ^ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819.
- ^ Ljunggren, B.; Oja, T. (1961), "The Uppsala spectral classification", Uppsala Astronomical Observatory Annual, 4 (10): 10, Bibcode:1961UppAn...4j...1L.
- ^ Samus', N. N.; et al. (2017), "General catalogue of variable stars: Version GCVS 5.1", Astronomy Reports, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
- Eggen, Olin J. (July 1998), "The Age Range of Hyades Stars", The Astronomical Journal, 116 (1): 284–292, Bibcode:1998AJ....116..284E, doi:10.1086/300413.
- ^ David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID 33401607.
- ^ van Saders, Jennifer L.; Pinsonneault, Marc H. (October 2013), "Fast Star, Slow Star; Old Star, Young Star: Subgiant Rotation as a Population and Stellar Physics Diagnostic", The Astrophysical Journal, 776 (2): 20, arXiv:1306.3701, Bibcode:2013ApJ...776...67V, doi:10.1088/0004-637X/776/2/67, S2CID 119097746, 67.
- Gebran, M.; et al. (November 2010), "Chemical composition of A and F dwarfs members of the Hyades open cluster", Astronomy and Astrophysics, 523: A71, arXiv:1006.5284, Bibcode:2010A&A...523A..71G, doi:10.1051/0004-6361/200913273, S2CID 7164596.
- "HD 161840". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-08-06.
- Peterson, D. M.; Baron, R. L.; Dunham, E.; Mink, D.; Weekes, T. C.; Elliot, J. L. (February 1981), "Lunar occultations of the Hyades: 1979-1980", Astronomical Journal, 86: 280–289, Bibcode:1981AJ.....86..280P, doi:10.1086/112886.
- Richichi, A.; et al. (October 1999), "New binary stars discovered by lunar occultations. IV", Astronomy and Astrophysics, 350: 491–496, Bibcode:1999A&A...350..491R.
- Eggleton, P. P.; Tokovinin, A. A. (2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
