HD 85512

HD 85512 is a solitary K-type main-sequence star located approximately 37 light-years away in the constellation Vela. It is approximately one billion years older than the Sun. It is extremely chromospherically inactive, only slightly more active than Tau Ceti. The star is known to host one low-mass planet.

HD 85512

Close-up of the sky around the star HD 85512. Credit: ESO and Digitized Sky Survey 2.
Observation data Epoch J2000      Equinox J2000
Constellation	Vela
Right ascension	09^h 51^m 07.0520^s[1]
Declination	−43° 30′ 10.0220″[1]
Apparent magnitude (V)	7.66
Characteristics
Spectral type	K5V
U−B color index	1.12
B−V color index	1.18
V−R color index	0.71
Astrometry
Radial velocity (Rv)	−9.6 km/s
Proper motion (μ)	RA: 461.446±0.103[1] mas/yr Dec.: −472.010±0.116[1] mas/yr
Parallax (π)	88.6158 ± 0.0406[1] mas
Distance	36.81 ± 0.02 ly (11.285 ± 0.005 pc)
Absolute magnitude (MV)	7.39[2]
Details
Mass	0.69 M☉
Radius	0.533 ± 0.04[note 1] R☉
Luminosity (bolometric)	0.126 ± 0.008 L☉
Surface gravity (log g)	4.39 ± 0.28 cgs
Temperature	4715 ± 102 K
Metallicity	44–50%
Rotation	47.13 ± 6.98
Rotational velocity (v sin i)	<3 km/s
Age	5.61 ± 0.61 Gyr
Other designations
CD−42°5678, GJ 370, HD 85512, HIP 48331, LHS 2201, 2MASS J09510700-4330097[3]
Database references
SIMBAD	data

Planetary system

Artists's impression of HD 85512 b.[4] Credit: ESO/M. Kornmesser.

On August 19, 2011, a ≥3.6 Earth-mass planet was discovered using HARPS that is "just inside" the habitable zone, along with the planets of 82 G. Eridani and HR 7722 c.[5] The planet could be potentially cool enough to host liquid water if the planet exhibits more than 50% cloud coverage. HD 85512 b is currently the fifth best candidate for habitability according to the Habitable Exoplanets Catalog.

The HD 85512 planetary system[5]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	≥3.6 M⊕	0.26 ± 0.005	58.43 ± 0.13	0.11 ± 0.1	—	—

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. Holmberg, J.; et al. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics, 501 (3): 941–947, arXiv:0811.3982, Bibcode:2009A&A...501..941H, doi:10.1051/0004-6361/200811191.
3. "HD 85512". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-09-22.
4. "Fifty New Exoplanets Discovered by HARPS". ESO Science Release. 12 September 2011. Retrieved 13 September 2011.
5. Pepe, F.; et al. (2011). "The HARPS search for Earth-like planets in the habitable zone. I. Very low-mass planets around HD 20794, HD 85512, and HD 192310". Astronomy and Astrophysics. 534. A58. arXiv:1108.3447. Bibcode:2011A&A...534A..58P. doi:10.1051/0004-6361/201117055.

Notes

1. From ${\displaystyle R={\sqrt {\frac {L}{4\pi \sigma T_{\rm {eff}}^{4}}}}}$, where ${\displaystyle R}$ is the radius, ${\displaystyle L}$ is the luminosity, ${\displaystyle T_{\rm {eff}}}$ is the effective surface temperature and ${\displaystyle \sigma }$ is the Stefan–Boltzmann constant.

External links

• "ARICNS: 00766". ARICNS. Centre of Astronomy, Heidelberg University.