| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Taurus |
| Right ascension | 04h 30m 33.633s [1] |
| Declination | +16° 11′ 38.46″ [1] |
| Apparent magnitude (V) | 4.78 [2] |
| Characteristics | |
| Spectral type | A6 IV [3] or A7 V [4] |
| B−V color index | +0.170±0.001 [2] |
| Variable type | suspected δ Sct [5] |
| Astrometry | |
| Radial velocity (Rv) | +38.1±0.8 [2] km/s |
| Proper motion (μ) |
RA: +104.422
[1]
mas/
yr Dec.: −26.254 [1] mas/ yr |
| Parallax (π) | 22.0357 ± 0.2516 mas [1] |
| Distance | 148 ± 2
ly (45.4 ± 0.5 pc) |
| Absolute magnitude (MV) | +1.58 [6] |
| Details | |
| Mass | 1.75 [7] M☉ |
| Radius | 2.209 [8] R☉ |
| Luminosity | 19.03 [2] L☉ |
| Surface gravity (log g) | 4.17±0.14 [7] cgs |
| Temperature | 8,274±281 [7] K |
| Metallicity [Fe/H] | +0.30 [9] dex |
| Rotation | 1.278 d [8] |
| Rotational velocity (v sin i) | 87.5 [8] km/s |
| Age | 307 [7] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 28527 is a star in the constellation Taurus, and a member of the Hyades open cluster. [8] It is faintly visible to the naked eye with an apparent visual magnitude of 4.78. [2] The distance to this star, as determined from its parallax shift of 22 mas, [1] is 148 light years. It is moving away from the Earth with a heliocentric radial velocity of +38 km/s. [2]
Based upon a stellar classification of A6 IV by Cowley et al. (1969), [3] 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. [4] At the age of 307 [7] million years, it has a high rate of spin, revolving upon its axis once every 1.278 days. [8] It is a Delta Scuti variable [5] with 1.75 [7] times the mass of the Sun and 2.2 [8] times the Sun's radius. The star is radiating 19 [2] times the Sun's luminosity from its photosphere at an effective temperature of 8,274 K. [7]
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. [11] [12] 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″. [13]
- ^ a b c d e f 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.
- ^ a b c d e f g 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.
- ^ a b 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.
- ^ a b Ljunggren, B.; Oja, T. (1961), "The Uppsala spectral classification", Uppsala Astronomical Observatory Annual, 4 (10): 10, Bibcode: 1961UppAn...4j...1L.
- ^ a b 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.
- ^ a b c d e f g 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.
- ^ a b c d e f 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.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Taurus |
| Right ascension | 04h 30m 33.633s [1] |
| Declination | +16° 11′ 38.46″ [1] |
| Apparent magnitude (V) | 4.78 [2] |
| Characteristics | |
| Spectral type | A6 IV [3] or A7 V [4] |
| B−V color index | +0.170±0.001 [2] |
| Variable type | suspected δ Sct [5] |
| Astrometry | |
| Radial velocity (Rv) | +38.1±0.8 [2] km/s |
| Proper motion (μ) |
RA: +104.422
[1]
mas/
yr Dec.: −26.254 [1] mas/ yr |
| Parallax (π) | 22.0357 ± 0.2516 mas [1] |
| Distance | 148 ± 2
ly (45.4 ± 0.5 pc) |
| Absolute magnitude (MV) | +1.58 [6] |
| Details | |
| Mass | 1.75 [7] M☉ |
| Radius | 2.209 [8] R☉ |
| Luminosity | 19.03 [2] L☉ |
| Surface gravity (log g) | 4.17±0.14 [7] cgs |
| Temperature | 8,274±281 [7] K |
| Metallicity [Fe/H] | +0.30 [9] dex |
| Rotation | 1.278 d [8] |
| Rotational velocity (v sin i) | 87.5 [8] km/s |
| Age | 307 [7] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 28527 is a star in the constellation Taurus, and a member of the Hyades open cluster. [8] It is faintly visible to the naked eye with an apparent visual magnitude of 4.78. [2] The distance to this star, as determined from its parallax shift of 22 mas, [1] is 148 light years. It is moving away from the Earth with a heliocentric radial velocity of +38 km/s. [2]
Based upon a stellar classification of A6 IV by Cowley et al. (1969), [3] 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. [4] At the age of 307 [7] million years, it has a high rate of spin, revolving upon its axis once every 1.278 days. [8] It is a Delta Scuti variable [5] with 1.75 [7] times the mass of the Sun and 2.2 [8] times the Sun's radius. The star is radiating 19 [2] times the Sun's luminosity from its photosphere at an effective temperature of 8,274 K. [7]
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. [11] [12] 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″. [13]
- ^ a b c d e f 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.
- ^ a b c d e f g 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.
- ^ a b 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.
- ^ a b Ljunggren, B.; Oja, T. (1961), "The Uppsala spectral classification", Uppsala Astronomical Observatory Annual, 4 (10): 10, Bibcode: 1961UppAn...4j...1L.
- ^ a b 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.
- ^ a b c d e f g 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.
- ^ a b c d e f 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.
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