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
Declination	−43° 30′ 10.0220″
Apparent magnitude (V)	7.66
Characteristics
Spectral type	K6V
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 mas/yr ; Dec.: −472.010±0.116 mas/yr
Parallax (π)	88.6158 ± 0.0406 mas
Distance	36.81 ± 0.02 ly ; (11.285 ± 0.005 pc)
Absolute magnitude (MV)	7.39
Details
Mass	0.69 M☉
Radius	0.533 ± 0.04 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
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

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

^ ^a ^b ^c ^d ^e 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.
^ ^a ^b ^c 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.
^ ^a ^b 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.

[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.

[1]

[2]

[3]

[4]

[note 1]

[5]

[6]

[7]

[8]

[9]

Observation data Epoch J2000 Equinox J2000
Close-up of the sky around the star HD 85512. Credit: ESO and Digitized Sky Survey 2.
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	K6V^[2]
U−B color index	1.12
B−V color index	1.18
V−R color index	0.71
Astrometry

Radial velocity (R_v)	−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 mas^[1]
Distance	36.81 ± 0.02 ly (11.285 ± 0.005 pc)
Absolute magnitude (M_V)	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