83 Leonis

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83 Leonis
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Leo
83 Leonis A
Right ascension 11h 26m 45.32s[1]
Declination +3° 0′ 47.2″[1]
Apparent magnitude (V) 6.49
83 Leonis B
Right ascension 11h 26m 46.28s[1]
Declination +03° 00′ 22.8″[1]
Apparent magnitude (V) 7.57
Spectral type K0IV / K2V
Variable type None
83 Leonis A
Proper motion (μ) RA: -725.74 ± 0.85[1] mas/yr
Dec.: 180.67 ± 0.87[1] mas/yr
Parallax (π)56.35 ± 0.75[1] mas
Distance57.9 ± 0.8 ly
(17.7 ± 0.2 pc)
83 Leonis B
Proper motion (μ) RA: -730.81 ± 1.59[1] mas/yr
Dec.: 188.97 ± 1.60[1] mas/yr
Parallax (π)55.69 ± 1.46[1] mas
Distance59 ± 2 ly
(18.0 ± 0.5 pc)
83 Leonis A
Radius1.9 R
Temperature5509 ± 8.6[2] K
83 Leonis B
Mass0.83[3] M
Radius0.96 ± 0.11[3] R
Luminosity (bolometric)0.418 ± 0.057[3] L
Surface gravity (log g)4.77[3] cgs
Temperature4740[3] K
Rotation1.4 km/s[3]
Age4 × 109[3] years
Other designations
BD+03° 2502/3, GJ 429, HD 99491/99492, HIP 55846, HR 4414, Wolf 393[4]
Database references
HD 99492

83 Leonis, abbreviated 83 Leo, is a binary star system approximately 58 light-years away in the constellation of Leo (the Lion). The primary star of the system is a cool orange subgiant star, while the secondary star is an orange dwarf star. The two stars are separated by at least 515 astronomical units from each other. Both stars are presumed to be cooler than the Sun.

In 2005, an extrasolar planet[5] was confirmed to be orbiting the secondary star within the system.

In 2010 the second planet was discovered.[3]

Stellar system[edit]

The primary component, 83 Leonis A, is a 6th magnitude star. It is not visible to the unaided eye, but easily visible with small binoculars. The star is classified as a subgiant, meaning that it has ceased fusing hydrogen in its core and started to evolve towards red gianthood.

The secondary component, 83 Leonis B, is an 8th magnitude orange dwarf, somewhat less massive (0.88 MSun), smaller and cooler than the Sun.[6] It is visible only with binoculars or better equipment. Components A and B share common proper motion, which confirms them as a physical pair. The projected separation between the stars is 515 AU, but the true separation may be much higher.[7]

There is yet another, magnitude 14.4 component listed in the Washington Double Star Catalog. However, this star is moving into a different direction and is therefore not a true member of the 83 Leonis system.

Planetary system[edit]

Planet 83 Leonis Bb was discovered in Jan 2005 by the California and Carnegie Planet Search team, who use the radial velocity method to detect planets. The planet's minimum mass is less than half of the mass of Saturn. It orbits very close to the star, completing one orbit in about 17 days.

In 2010 the second planet 83 Leonis Bc was discovered.[3]

The 83 Leonis B planetary system[3]
(in order from star)
Mass Semimajor axis
Orbital period
Eccentricity Inclination Radius
b ≥ 0.087 ± 0.006 MJ 0.12186 ± 0.00002 17.054 ± 0.003 0.13 ± 0.07
c ≥ 0.36 ± 0.06 MJ 5.4 ± 0.5 4970 ± 744 0.1 ± 0.2

See also[edit]


  1. ^ a b c d e f g h i j van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752Freely accessible. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.  Vizier catalog entry for A Vizier catalog entry for B
  2. ^ Kovtyukh, V. V.; et al. (2003). "High precision effective temperatures for 181 F-K dwarfs from line-depth ratios". Astronomy and Astrophysics. 411 (3): 559–564. arXiv:astro-ph/0308429Freely accessible. Bibcode:2003A&A...411..559K. doi:10.1051/0004-6361:20031378. 
  3. ^ a b c d e f g h i j k Stefano Meschiari; Gregory Laughlin; Steven S. Vogt; R. Paul Butler; Eugenio J. Rivera; Nader Haghighipour; Peter Jalowiczor (2011). "The Lick-Carnegie Survey: Four New Exoplanet Candidates". The Astrophysical Journal. 727 (2). article id. 117. arXiv:1011.4068Freely accessible. Bibcode:2011ApJ...727..117M. doi:10.1088/0004-637X/727/2/117. 
  4. ^ "83 Leo". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 15 February 2018. 
  5. ^ Marcy, Geoffrey W.; et al. (2005). "Five New Extrasolar Planets". The Astrophysical Journal. 619 (1): 570–584. Bibcode:2005ApJ...619..570M. CiteSeerX accessible. doi:10.1086/426384. 
  6. ^ "The Planet Around HD 99492". California & Carnegie Planet Search. Archived from the original on 2005-12-16. Retrieved 2006-05-09. 
  7. ^ Raghavan, Deepak; Henry, Todd J.; Mason, Brian D.; Subasavage, John P.; Jao, Wei‐Chun; Beaulieu, Thom D.; Hambly, Nigel C. (2006). "Two Suns in The Sky: Stellar Multiplicity in Exoplanet Systems". The Astrophysical Journal. 646 (1): 523–542. arXiv:astro-ph/0603836Freely accessible. Bibcode:2006ApJ...646..523R. doi:10.1086/504823. 

External links[edit]

Coordinates: Sky map 11h 26m 45.32s, +03° 00′ 47.18″