HD 290327

HD 290327 is a single[7] star in the equatorial constellation of Orion. It has a yellow hue with an apparent visual magnitude of 8.99,[2] which is too faint to be viewed with the naked eye. Parallax measurements provide a distance estimate of 184 light years from the Sun. It is drifting away with a radial velocity of +29.5 km/s,[1] having come to within 124 light-years around a million years ago.[2]

HD 290327

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Orion
Right ascension	05^h 23^m 21.56388^s[1]
Declination	–02° 16′ 39.4338″[1]
Apparent magnitude (V)	8.99[2]
Characteristics
Spectral type	G5IV[3] or G8V[4]
Apparent magnitude (B)	9.751[2]
Apparent magnitude (J)	7.683±0.026[2]
Apparent magnitude (H)	7.404±0.047[2]
Apparent magnitude (K)	7.271±0.027[2]
B−V color index	0.761±0.033[2]
Astrometry
Radial velocity (Rv)	+29.52±0.21[1] km/s
Proper motion (μ)	RA: +32.312[1] mas/yr Dec.: −97.224[1] mas/yr
Parallax (π)	17.6913 ± 0.0461[1] mas
Distance	184.4 ± 0.5 ly (56.5 ± 0.1 pc)
Absolute magnitude (MV)	5.24[2]
Details[5]
Mass	0.86±0.01 M☉
Radius	0.95±0.02 R☉
Luminosity	0.747±0.004 L☉
Surface gravity (log g)	4.41±0.01 cgs
Temperature	5,525±20 K
Metallicity [Fe/H]	−0.11 dex
Rotational velocity (v sin i)	1.44±1.0[4] km/s
Age	11.8±1.2 Gyr
Other designations
BD−02°128, HD 290327, HIP 25191, SAO 132049, PPM 175811[6]
Database references
SIMBAD	data
Exoplanet Archive	data
Extrasolar Planets Encyclopaedia	data

Kazanasmas (1973) found a stellar classification of G5IV[3] for this object, matching a G-type star that is evolving along the subgiant branch. It was later given a class of G8V,[4] suggesting it is instead a G-type main-sequence star. This object is nearly twelve[5] billion years old and is spinning slowly with a projected rotational velocity of 1.4 km/s.[4] The star has 86% of the mass of the Sun and 95% of the Sun's radius. It is radiating 75% of the luminosity of the Sun from its photosphere at an effective temperature of 5,525 K. The metallicity is sub-solar,[5] meaning it has a lower abundance of elements other than hydrogen and helium compared to the Sun.

In 2009, a gas giant planet was found in orbit around the star. It is orbiting at a distance of around 3.4 AU with a period of 6.7 years.[4]

The HD 290327 planetary system[4]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	≥ 2.54+0.17 −0.14 MJ	3.43+0.20 −0.12	2443+205 −117	0.08+0.08 −0.03	—	—

See also

• List of extrasolar planets

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. 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.
3. Kazanasmas, M. S. (1973). "Catalogue of magnitudes, color indices, spectral and luminosity classes of stars in Orion". Abastumanskaya Astrofiz. Obs., Byull. 44: 175. Bibcode:1973AbaOB..44..175K.
4. Naef, D.; et al. (2010). "The HARPS search for southern extrasolar planets XXIII. 8 planetary companions to low-activity solar-type stars". Astronomy and Astrophysics. 523. A15. arXiv:1008.4600. Bibcode:2010A&A...523A..15N. doi:10.1051/0004-6361/200913616.
5. Bonfanti, A.; et al. (2015). "Revising the ages of planet-hosting stars". Astronomy and Astrophysics. 575. A18. arXiv:1411.4302. Bibcode:2015A&A...575A..18B. doi:10.1051/0004-6361/201424951.
6. "HD 290327". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-11-18.
7. Ginski, C.; et al. (2016). "A lucky imaging multiplicity study of exoplanet host stars – II". Monthly Notices of the Royal Astronomical Society. 457 (2): 2173–2191. arXiv:1601.01524. Bibcode:2016MNRAS.457.2173G. doi:10.1093/mnras/stw049.