HD 85512

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	09h 51m 07.0520s[1]
Declination	−43° 30′ 10.0220″[1]
Apparent magnitude (V)	7.66
Characteristics
Spectral type	K6V[2]
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[3]
Details[2][4]
Mass	0.69 M☉
Radius	0.533 ± 0.04[note 1] R☉
Luminosity (bolometric)	0.126 ± 0.008 L☉
Surface gravity (log g)	4.604±0.017 cgs
Temperature	4404±10 K
Metallicity	([Si/H] dex) -0.02
Metallicity [Fe/H]	-0.28 dex
Rotation	47.13 ± 6.98
Rotational velocity (v sin i)	2.194±0.118 km/s
Age	5.61 ± 0.61 Gyr
Other designations
	CD−42°5678, Gaia DR2 5412947081287925504, GJ 370, HD 85512, HIP 48331, LHS 2201, 2MASS J09510700-4330097[5]
Database references
SIMBAD	data

HD 85512 is a solitary K-type main-sequence star about 37 light-years away in the constellation Vela. It is about 1 billion years older than the Sun. It is extremely chromospherically inactive, only slightly more active than Tau Ceti. It exhibits a long-term variability[2] and is known to host one low-mass planet.

Planetary system

Artists's impression of HD 85512 b.[6] 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: inner planets of e (or 82 G.) Eridani; and HR 7722 c in Capricornus. These two comparator sets are at about ²⁄₃ of the subject's distance from Earth.[7] The subject planet could be cool enough to host liquid water if it has more than 50% cloud coverage. For a time it ranked fifth-best for habitability in the Habitable Exoplanets Catalog, which later lists it under false starts as "too hot".[8]

The HD 85512 planetary system[7]
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	—	—

Position

The star lies in Vela, 3′32″ west of, and 10′54″ north of LZ Velorum (HD 86005), a chromospherically active giant, variable star, at 2090 light years away, of orange-to-red color. It has similar average magnitude.[9]

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. Gaia DR2 record for this source at VizieR.
Anglada-Escudé, Guillem; Butler, R. Paul (2012), "The HARPS-TERRA project. I. Description of the algorithms, performance, and new measurements on a few remarkable stars observed by HARPS", The Astrophysical Journal Supplement Series, 200 (2): 15, arXiv:1202.2570, doi:10.1088/0067-0049/200/2/15, S2CID 118528839
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, S2CID 118577511.
Spectroscopic Parameters and atmosphEric ChemIstriEs of Stars (SPECIES) I. Code description and dwarf stars catalogue Full table D.1
"HD 85512". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-09-22.
"Fifty New Exoplanets Discovered by HARPS". ESO Science Release. 12 September 2011. Retrieved 13 September 2011.
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.
http://phl.upr.edu/library/notes/falsestarts
https://www.universeguide.com/star/48598/lzvelorum

Notes

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

External links

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

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[Gaia_DR2-1] 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.

[Escude2012-2] Anglada-Escudé, Guillem; Butler, R. Paul (2012), "The HARPS-TERRA project. I. Description of the algorithms, performance, and new measurements on a few remarkable stars observed by HARPS", The Astrophysical Journal Supplement Series, 200 (2): 15, arXiv:1202.2570, doi:10.1088/0067-0049/200/2/15, S2CID 118528839

[Holmberg2009-3] 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, S2CID 118577511.

[Soto2018-4] Spectroscopic Parameters and atmosphEric ChemIstriEs of Stars (SPECIES) I. Code description and dwarf stars catalogue Full table D.1

[Simbad-6] "HD 85512". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-09-22.

[7] "Fifty New Exoplanets Discovered by HARPS". ESO Science Release. 12 September 2011. Retrieved 13 September 2011.

[Pepe2011-8] 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.

[9] ttp://phl.upr.edu/library/notes/falsestarts

[10] ttps://www.universeguide.com/star/48598/lzvelorum

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