HD 93385

HD 93385
Observation data
Epoch J2000      Equinox J2000
Constellation Vela
Right ascension 10h 46m 15.116s[1]
Declination –41° 27′ 51.73″[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: −48.135 mas/yr[1]
Dec.: −54.551 mas/yr[1]
Parallax (π)23.1489 ± 0.018 mas[1]
Distance140.9 ± 0.1 ly
(43.20 ± 0.03 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

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 23.15 mas. This is equivalent to a physical separation of around 141[1] light years from the Sun. It is drifting further away with a radial velocity of +47.8 km/s.

This is an ordinary G-type 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] A 2015 survey ruled out the existence of any additional stellar companions at projected distances from 12 to 352 astronomical units.[9]

Planetary system

[edit]

This star hosts two close-orbiting, super-Earth-like planets, suspected since 2011 and confirmed in 2021.[10][11] 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.[12] A third planet on an innermost orbit was discovered in 2017[13] and confirmed in 2021.[11]

The HD 93385 A planetary system[11]
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(days) 		Eccentricity Inclination Radius
b ≥4.2±0.5 M🜨 0.0756±0.0013 7.3426±0.0012 <0.295 — —
c ≥7.1±0.6 M🜨 0.112±0.002 13.180±0.003 <0.20 — —
d ≥8.7±0.9 M🜨 0.2565±0.0043 45.85±0.05 0.09+0.15
−0.05 		— —

References

[edit]
  1. ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  2. ^ a b 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. ^ a b Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 1, Ann Arbor, Michigan: Department of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
  4. ^ a b c d e 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. ^ a b c d e f 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, S2CID 118565025.
  7. ^ "HD 93385". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2013-10-07.{{cite web}}: CS1 maint: postscript (link)
  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, S2CID 43663915.
  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): 3127–3136, Bibcode:2015MNRAS.450.3127M, doi:10.1093/mnras/stv771, hdl:1887/49340, 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, S2CID 118410500.
  11. ^ a b c Unger, N.; et al. (October 2021), "The HARPS search for southern extra-solar planets XLVI: 12 super-Earths around the solar type stars HD39194, HD93385, HD96700, HD154088, and HD189567", Astronomy & Astrophysics, 654: 19, arXiv:2108.10198, Bibcode:2021A&A...654A.104U, doi:10.1051/0004-6361/202141351, A104
  12. ^ Zolotukhin, Ivan, "Catalog", Extrasolar Planets Encyclopaedia, retrieved 2013-10-07.
  13. ^ Gillon, M.; et al. (May 2017), "The Spitzer search for the transits of HARPS low-mass planets - II. Null results for 19 planets", Astronomy & Astrophysics, 601: 23, arXiv:1701.01303, Bibcode:2017A&A...601A.117G, doi:10.1051/0004-6361/201629270, A117
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