HD 210277

HD 210277 is a single[8] star in the equatorial constellation of Aquarius. It has an apparent visual magnitude of 6.54,[2] which makes it a challenge to view with the naked eye, but it is easily visible in binoculars. The star is located at a distance of 69.5 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −20.9 km/s.[5]

HD 210277
Observation data
Epoch J2000      Equinox J2000
Constellation Aquarius
Right ascension 22h 09m 29.86572s[1]
Declination −07° 32 55.1630[1]
Apparent magnitude (V) 6.54[2]
Characteristics
Spectral type G8V[3] or G8/K0V[4]
U−B color index 0.43
B−V color index 0.773
Astrometry
Radial velocity (Rv)−20.855±0.0003[5] km/s
Proper motion (μ) RA: 85.462[1] mas/yr
Dec.: −450.544[1] mas/yr
Parallax (π)46.9229 ± 0.0481[1] mas
Distance69.51 ± 0.07 ly
(21.31 ± 0.02 pc)
Absolute magnitude (MV)4.90±0.05[6]
Details[7]
Mass1.007+0.040
−0.039
 M
Radius1.087+0.015
−0.016
 R
Surface gravity (log g)4.369±0.020 cgs
Temperature5,705±35 K
Metallicity [Fe/H]0.170±0.097 dex
Rotation40.8 d[8]
Rotational velocity (v sin i)1.888±0.158 km/s
Age6.471+1.744
−1.643
[7]
8.929±2.671[2] Gyr
Other designations
BD−08°5818, GJ 9769, HD 210277, HIP 109378, SAO 145906, PPM 206033, LTT 8887, NLTT 53073, GCRV 13920[9]
Database references
SIMBADdata
ARICNSdata
Extrasolar Planets
Encyclopaedia
data

An early classification of this star was a G0 dwarf,[10] and some sources still use this value.[11] More modern classification surveys list it as G8V,[3] matching a late G-type main-sequence star.[8] It is older than the Sun with a very low level of chromospheric activity [3] and is spinning with a projected rotational velocity of 1.9 km/s. The star has a slightly higher mass and larger radius than the Sun.[7]

In 1999 it was announced that a dust disk orbiting HD 210277, similar to that produced by the Kuiper Belt, had been imaged, lying between 30 and 62 AU from the star.[12] However, observations with the Spitzer Space Telescope failed to detect any infrared excess at 70 micrometres or at 24 micrometres wavelengths.[13][14] Subsequent measurements by the Herschel Space Observatory did detect an excess at 100 and 160 micrometres. A model fit to the emission matches a disk orbiting at 160 AU with a mean temperature of 22 K.[15]

The only known exoplanet was discovered using 34 radial velocity measurements taken from 1996 to 1998 at W. M. Keck Observatory. It has a minimum mass greater than Jupiter orbiting the star in 442 days.[8] The high eccentricity (ovalness) of the exoplanet's orbit means it is unlikely that there is a companion planet co-orbiting the star at a trojan point.[11]

The HD 210277 planetary system[16]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b >1.29 ± 0.11 MJ 1.138 ± 0.066 442.19 ± 0.50 0.476 ± 0.017

References

  1. 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. Gaia DR2 record for this source at VizieR.
  2. Delgado Mena, E.; et al. (April 2019). "Abundance to age ratios in the HARPS-GTO sample with Gaia DR2. Chemical clocks for a range of [Fe/H]". Astronomy & Astrophysics. 624: 24. arXiv:1902.02127. Bibcode:2019A&A...624A..78D. doi:10.1051/0004-6361/201834783. A78.
  3. Gray, R. O.; et al. (October 2003). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 Parsecs: The Northern Sample. I.". The Astronomical Journal. 126 (4): 2048–2059. arXiv:astro-ph/0308182. Bibcode:2003AJ....126.2048G. doi:10.1086/378365. S2CID 119417105.
  4. Houk, N.; Swift, C. (1999). "Michigan catalogue of two-dimensional spectral types for the HD Stars". Michigan Spectral Survey. 5. Bibcode:1999MSS...C05....0H.
  5. Soubiran, C.; et al. (2018). "Gaia Data Release 2. The catalogue of radial velocity standard stars". Astronomy and Astrophysics. 616: A7. arXiv:1804.09370. Bibcode:2018A&A...616A...7S. doi:10.1051/0004-6361/201832795. S2CID 52952408.
  6. Gonzalez, Guillermo; et al. (1999). "Parent Stars of Extrasolar Planets. IV. 14 Herculis, HD 187123, and HD 210277". The Astrophysical Journal Letters. 511 (2): L111–L114. Bibcode:1999ApJ...511L.111G. doi:10.1086/311847.
  7. Soto, M. G.; Jenkins, J. S. (2018). "Spectroscopic Parameters and atmosphEric ChemIstriEs of Stars (SPECIES). I. Code description and dwarf stars catalogue". Astronomy and Astrophysics. 615: A76. arXiv:1801.09698. Bibcode:2018A&A...615A..76S. doi:10.1051/0004-6361/201731533.
  8. Marcy, Geoffrey W.; et al. (1999). "Two New Planets in Eccentric Orbits". The Astrophysical Journal. 520 (1): 239–247. arXiv:astro-ph/9904275. Bibcode:1999ApJ...520..239M. doi:10.1086/307451. S2CID 16827678.
  9. "HD 210277". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-12-29.
  10. Cannon, A. J.; Pickering, E. C. (October 1993). "Henry Draper Catalogue and Extension". VizieR On-line Data Catalog: III/135A. Bibcode:1993yCat.3135....0C. Originally published in: Harv. Ann. 91-100 (1918-1924)
  11. Funk, B.; Schwarz, R.; Süli, Á.; Érdi, B. (July 2012). "On the stability of possible Trojan planets in the habitable zone: an application to the systems HD 147513 and HD 210277". Monthly Notices of the Royal Astronomical Society. 423 (4): 3074–3082. Bibcode:2012MNRAS.423.3074F. doi:10.1111/j.1365-2966.2012.21121.x.
  12. Trilling, D. E.; et al. (2000). "Circumstellar Dust Disks around Stars with Known Planetary Companions". The Astrophysical Journal. 529 (1): 499–505. Bibcode:2000ApJ...529..499T. doi:10.1086/308280.
  13. Beichman, C. A.; et al. (2005). "Planets and Infrared Excesses: Preliminary Results from a Spitzer MIPS Survey of Solar-Type Stars". The Astrophysical Journal. 622 (2): 1160–1170. arXiv:astro-ph/0412265. Bibcode:2005ApJ...622.1160B. doi:10.1086/428115. S2CID 6633656.
  14. Bryden, G.; et al. (2009). "Planets and Debris Disks: Results from a Spitzer/MIPS Search for Infrared Excess" (PDF). The Astrophysical Journal. 705 (2): 1226–1236. Bibcode:2009ApJ...705.1226B. doi:10.1088/0004-637X/705/2/1226.
  15. Eiroa, C.; et al. (December 2011). "Herschel discovery of a new class of cold, faint debris discs". Astronomy & Astrophysics. 536: L4. arXiv:1110.4826. Bibcode:2011A&A...536L...4E. doi:10.1051/0004-6361/201117797.
  16. Butler, R. P.; et al. (2006). "Catalog of Nearby Exoplanets". The Astrophysical Journal. 646 (1): 505–522. arXiv:astro-ph/0607493. Bibcode:2006ApJ...646..505B. doi:10.1086/504701. S2CID 119067572.

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