HD 93385

HD 93385 is a star in the southern constellation of Vela. At an apparent visual magnitude of 7.5,[2] it is too faint to be seen with the unaided eye. Parallax measurements made using the Gaia spacecraft show an annual shift of 23.04 milli-arcseconds. This is equivalent to a physical separation of around 142[1] light years from the Sun.

HD 93385
Observation data
Epoch J2000      Equinox J2000
Constellation Vela
Right ascension 10h 46m 15.1160s[1]
Declination –41° 27′ 51.7261″[1]
Apparent magnitude (V) 7.486[2]
Characteristics
Spectral type G2/G3 V[3]
B−V color index 0.595[4]
Astrometry
Radial velocity (Rv)+47.80 ± 0.61[5] km/s
Proper motion (μ) RA: −48.197±0.045[1] mas/yr
Dec.: −54.727±0.043[1] mas/yr
Parallax (π)23.0405 ± 0.0342[1] mas
Distance141.6 ± 0.2 ly
(43.40 ± 0.06 pc)
Details
Mass1.07[4] M☉
Radius1.17[6] R☉
Luminosity1.42[6] L☉
Surface gravity (log g)4.08 ± 0.11[6] cgs
Temperature5,823 ± 35[6] K
Metallicity [Fe/H]–0.05 ± 0.03[6] dex
Age4.13[4] Gyr
Other designations
CD–40 6283, HD 93385, HIP 52676, SAO 222310.[7]
Database references
SIMBADdata

This is an ordinary main sequence star with a stellar classification of G2/G3 V.[3] The physical properties of HD 93385 are similar to those of the Sun; it is slightly larger with 107%[4] of the Sun's mass, 117% of the radius, and 142% of the luminosity. The abundance of elements, other than hydrogen and helium, is nearly the same as in the Sun.[6] It is currently at an unusual low level of surface activity and thus is a candidate Maunder minimum analog.[4]

A physical companion star with an apparent visual magnitude of 12.29 is located at an angular separation of 10.32 arcseconds (equivalent to projected separation of 448 AU) along a position angle of 288°. It is estimated to have 45% of the mass of the Sun.[8]

The survey in 2015 have ruled out the existence of any additional stellar companions at projected distances from 12 to 352 astronomical units.[9]

Planetary system

This star hosts two close-orbiting, super-Earth-like planets.[10] The first has 8.3 times the mass of the Earth and an orbital period of 13.186 days. The second is 10.1 times the Earth's mass with a period of 46.025 days.[11]

The HD 93385 planetary system
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
Ab ≥8.3 M⊕ 0.1116±0.0018 13.186 0.15±0.11 — —
Ac ≥10.1 M⊕ 0.257±0.0043 46.025±0.00725 0.24±0.18 — —

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. Høg, E.; et al. (March 2000), "The Tycho-2 catalogue of the 2.5 million brightest stars", Astronomy and Astrophysics, 355: L27–L30, Bibcode:2000A&A...355L..27H, doi:10.1888/0333750888/2862.
  3. Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, 1, Ann Arbor, Michigan: Department of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
  4. Lubin, Dan; et al. (March 2012), "Frequency of Maunder Minimum Events in Solar-type Stars Inferred from Activity and Metallicity Observations", The Astrophysical Journal Letters, 747 (2): L32, Bibcode:2012ApJ...747L..32L, doi:10.1088/2041-8205/747/2/L32.
  5. Valenti, Jeff A.; Fischer, Debra A. (July 2005), "Spectroscopic Properties of Cool Stars (SPOCS). I. 1040 F, G, and K Dwarfs from Keck, Lick, and AAT Planet Search Programs", The Astrophysical Journal Supplement Series, 159 (1): 141–166, Bibcode:2005ApJS..159..141V, doi:10.1086/430500.
  6. Ghezzi, L.; et al. (September 2010), "Stellar Parameters and Metallicities of Stars Hosting Jovian and Neptunian Mass Planets: A Possible Dependence of Planetary Mass on Metallicity", The Astrophysical Journal, 720 (2): 1290–1302, arXiv:1007.2681, Bibcode:2010ApJ...720.1290G, doi:10.1088/0004-637X/720/2/1290.
  7. "HD 93385 -- Star", Strasbourg astronomical Data Center, Centre de Données astronomiques de Strasbourg, retrieved 2013-10-07.
  8. Tokovinin, Andrei (February 2011), "Low-mass Visual Companions to Nearby G-dwarfs", The Astronomical Journal, 141 (2): 52, arXiv:1011.2051, Bibcode:2011AJ....141...52T, doi:10.1088/0004-6256/141/2/52.
  9. Mugrauer, M.; Ginski, C. (12 May 2015). "High-contrast imaging search for stellar and substellar companions of exoplanet host stars". Monthly Notices of the Royal Astronomical Society. 450 (3). doi:10.1093/mnras/stv771. Retrieved 19 June 2020.
  10. González Hernández, J. I.; et al. (April 2013), "Searching for the signatures of terrestrial planets in F-, G-type main-sequence stars", Astronomy & Astrophysics, 552: A6, arXiv:1301.2109, Bibcode:2013A&A...552A...6G, doi:10.1051/0004-6361/201220165.
  11. Zolotukhin, Ivan, "Catalog", The Extrasolar Planet Encyclopedia, retrieved 2013-10-07.
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