HD 39194

Last updated
HD 39194
Observation data
Epoch J2000.0        Equinox J2000.0 (ICRS)
Constellation Mensa
Right ascension 05h 44m 31.9180s [1]
Declination −70° 08′ 36.858″ [1]
Apparent magnitude  (V)8.07±0.01 [2]
Characteristics
Spectral type K0 V [3]
U−B color index +0.26 [4] [5]
B−V color index +0.76 [4] [5]
Astrometry
Radial velocity (Rv)13.90±0.10 [6]  km/s
Proper motion (μ)RA: −309.273  mas/yr [1]
Dec.: +1238.862  mas/yr [1]
Parallax (π)37.8235 ± 0.0206  mas [1]
Distance 86.23 ± 0.05  ly
(26.44 ± 0.01  pc)
Absolute magnitude  (MV)+6.02 [7]
Details
Mass 0.71 [8]   M☉
Radius 0.74 [9]   R☉
Luminosity 0.389 [10]   L☉
Surface gravity (log g)4.61±0.05 [11]   cgs
Temperature 5,205±23 [11]   K
Metallicity [Fe/H]−0.61±0.02 [11]   dex
Rotational velocity (v sin i)2 [12]  km/s
Age 11.7 [8]   Gyr
Other designations
CD−70°340, CPD−70°447, GJ  217.2, HD  39194, HIP  27080, SAO  256232, LHS  210
Database references
SIMBAD data

HD 39194 (Gliese 217.2; LHS 210) is a star located in the southern circumpolar constellation Mensa. It has an apparent magnitude of 8.07, [2] making it readily visible in binoculars but not to the naked eye. The object is relatively close at a distance of 86 light years [1] but is receding with a heliocentric radial velocity of 13.9  km/s . [6]

Contents

Characteristics

HD 39194 has a general stellar classification of K0 V, [3] indicating that it is a K-type main-sequence star. Houk & Cowley found a slightly warmer class of G8 V, [13] instead making it a G-type main-sequence star. Nevertheless, it has 71% the mass of the Sun [8] and an effective temperature of 5,205  K , [11] giving an orange hue. It radius of 0.74  R☉ [9] yields a luminosity only 38% that of the Sun. [10] HD 39194 is estimated to be 11.7 billion years old [8] and is extremely chromospherically inactive. [3] Despite being a planetary host, it has an iron abundance only 24% that of the Sun. [11] HD 39194's projected rotational velocity is similar to the Sun's, with the value being 2  km/s . [12]

Planetary system

Three planet candidates around this star were first reported in a 2011 preprint. [14] After 10 years of observations, a team of astronomers confirmed 3 super-Earths circling HD 39194 in eccentric orbits; [10] none of the planets are in the habitable zone. HD 39194 b and d have similar masses.

This star was selected as a potential candidate for future exoplanet imaging missions in 2015. [9]

The HD 39194 planetary system [10]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b≥4.13±0.20  M🜨 0.056±0.0015.6368±0.0004<0.207——
c≥6.29±0.51  M🜨 0.103±0.00214.030±0.003<0.154——
d≥4.13±0.60  M🜨 0.185±0.00333.91±0.03<0.333——

See also

Related Research Articles

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<span class="mw-page-title-main">HD 27245</span> Star in the constellation Camelopardalis

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<span class="mw-page-title-main">HD 61005</span> Star in the constellation Puppis

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<span class="mw-page-title-main">HD 196737</span> K-type giant; Microscopium

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<span class="mw-page-title-main">HD 177565</span> Yellow dwarf w. a planet; Corona Australis

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References

  1. 1 2 3 4 5 6 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. 1 2 Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. ISSN   0004-6361.
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  4. 1 2 Eggen, O. J. (January 1979). "Catalogs of proper-motion stars. I - Stars brighter than visual magnitude 15 and with annual proper motion of 1 arcsec or more". The Astrophysical Journal Supplement Series. 39: 89. Bibcode:1979ApJS...39...89E. doi: 10.1086/190566 . eISSN   1538-4365. ISSN   0067-0049.
  5. 1 2 Sandage, Allan; Fouts, Gary (January 1987). "New subdwarfs. VI - Kinematics of 1125 high-proper-motion stars and the collapse of the Galaxy". The Astronomical Journal. 93: 74. Bibcode:1987AJ.....93...74S. doi: 10.1086/114291 . ISSN   0004-6256.
  6. 1 2 Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv: 1606.08053 . Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. ISSN   1063-7737. S2CID   119231169.
  7. ↑ Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv: 1108.4971 . Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID   119257644.
  8. 1 2 3 4 Luck, R. Earle (13 February 2018). "Abundances in the Local Region. III. Southern F, G, and K Dwarfs". The Astronomical Journal. 155 (3): 111. Bibcode:2018AJ....155..111L. doi: 10.3847/1538-3881/aaa9b5 . eISSN   1538-3881.
  9. 1 2 3 Margaret C Turnbull (2015). "ExoCat-1: The Nearby Stellar Systems Catalog for Exoplanet Imaging Missions". arXiv: 1510.01731 [astro-ph.SR].
  10. 1 2 3 4 Unger, N.; et al. (October 2021). "The HARPS search for southern extra-solar planets". Astronomy & Astrophysics. 654: A104. arXiv: 2108.10198 . Bibcode:2021A&A...654A.104U. doi: 10.1051/0004-6361/202141351 . eISSN   1432-0746. ISSN   0004-6361.
  11. 1 2 3 4 5 Sousa, S. G.; Santos, N. C.; Mayor, M.; Udry, S.; Casagrande, L.; Israelian, G.; Pepe, F.; Queloz, D.; Monteiro, M. J. P. F. G. (4 June 2008). "Spectroscopic parameters for 451 stars in the HARPS GTO planet search program". Astronomy & Astrophysics. 487 (1): 373–381. arXiv: 0805.4826 . Bibcode:2008A&A...487..373S. doi: 10.1051/0004-6361:200809698 . eISSN   1432-0746. ISSN   0004-6361.
  12. 1 2 Nordström, B.; Mayor, M.; Andersen, J.; Holmberg, J.; Pont, F.; Jørgensen, B. R.; Olsen, E. H.; Udry, S.; Mowlavi, N. (May 2004). "The Geneva-Copenhagen survey of the Solar neighbourhood: Ages, metallicities, and kinematic properties of ~14 000 F and G dwarfs". Astronomy & Astrophysics. 418 (3): 989–1019. arXiv: astro-ph/0405198 . Bibcode:2004A&A...418..989N. doi: 10.1051/0004-6361:20035959 . ISSN   0004-6361.
  13. ↑ Houk, N.; Cowley, A. P. (1975). University of Michigan Catalogue of two-dimensional spectral types for the HD stars. Volume I. Declinations -90° to -53.0°. Bibcode:1975mcts.book.....H.
  14. ↑ Mayor, M.; Marmier, M.; Lovis, C.; Udry, S.; Ségransan, D.; Pepe, F.; Benz, W.; Bertaux, J.-L.; Bouchy, F.; Dumusque, X.; Curto, G. Lo; Mordasini, C.; Queloz, D.; Santos, N. C. (2011). "The HARPS search for southern extra-solar planets XXXIV. Occurrence, mass distribution and orbital properties of super-Earths and Neptune-mass planets". arXiv: 1109.2497 [astro-ph.EP].
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