Astronomy:HD 93385

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Short description: Star in the constellation Vela
HD 93385
Observation data
Equinox J2000.0]] (ICRS)
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[1] mas/yr
Dec.: −54.551[1] mas/yr
Parallax (π)23.1489 ± 0.018[1] mas
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

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

  1. 1.0 1.1 1.2 1.3 1.4 Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode2021A&A...649A...1G.  Gaia EDR3 record for this source at VizieR.
  2. 2.0 2.1 Høg, E. et al. (March 2000), "The Tycho-2 catalogue of the 2.5 million brightest stars", Astronomy and Astrophysics 355: L27–L30, doi:10.1888/0333750888/2862, Bibcode2000A&A...355L..27H. 
  3. 3.0 3.1 Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, 1, Ann Arbor, Michigan: Department of Astronomy, University of Michigan, Bibcode1978mcts.book.....H. 
  4. 4.0 4.1 4.2 4.3 4.4 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, doi:10.1088/2041-8205/747/2/L32, Bibcode2012ApJ...747L..32L. 
  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, doi:10.1086/430500, Bibcode2005ApJS..159..141V. 
  6. 6.0 6.1 6.2 6.3 6.4 6.5 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, doi:10.1088/0004-637X/720/2/1290, Bibcode2010ApJ...720.1290G. 
  7. "HD 93385". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+93385. 
  8. Tokovinin, Andrei (February 2011), "Low-mass Visual Companions to Nearby G-dwarfs", The Astronomical Journal 141 (2): 52, doi:10.1088/0004-6256/141/2/52, Bibcode2011AJ....141...52T. 
  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, doi:10.1093/mnras/stv771, Bibcode2015MNRAS.450.3127M, https://academic.oup.com/mnras/article/450/3/3127/1063872, 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, doi:10.1051/0004-6361/201220165, Bibcode2013A&A...552A...6G. 
  11. 11.0 11.1 11.2 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, doi:10.1051/0004-6361/202141351, A104, Bibcode2021A&A...654A.104U 
  12. Zolotukhin, Ivan, Catalog, https://exoplanet.eu/catalog/?f=%27HD%2093385%27+in+name/, 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, doi:10.1051/0004-6361/201629270, A117, Bibcode2017A&A...601A.117G