Gliese 317

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Gliese 317
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Pyxis
Right ascension 08h 40m 59.24s
Declination −23° 27′ 23.3″
Apparent magnitude (V) 11.98
Characteristics
Spectral type M2.5V
Variable type none reported
Astrometry
Radial velocity (Rv) 87.8[1] km/s
Proper motion (μ) RA: -438 mas/yr
Dec.: 794 mas/yr
Parallax (π) 65.3 ± 0.5[1] mas
Distance 49.9 ± 0.4 ly
(15.3 ± 0.1 pc)
Other designations
GJ 317, LFT 538, LHS 2037, LPM 296, LTT 3215
Details
Mass 0.43 [1] M
Metallicity [Fe/H] +0.3[1][2] dex
Database references
SIMBAD data
Exoplanet Archive data
Extrasolar Planets
Encyclopaedia
data

Gliese 317 is a red dwarf approximately 50 light-years away in the constellation of Pyxis. As of 2011, two extrasolar planets have been confirmed to be orbiting the star.[1][3] Photometric calibrations and infrared spectroscopic measurements[2] indicate that the star is enriched in heavy elements compared to the Sun.

Planetary system[edit]

In 2007, a jovian planet (designated Gliese 317 b) was announced to orbit the star.[3] The planet orbits about 95% the distance between Earth to the Sun. Despite of this, it takes about 1.9 years, due to the lower mass of the central M dwarf. Astrometric measurements on Gliese 317 provided a significant update to the distance, putting the star at 15.3 pc, which is 65% further out than previously assumed.[1] Using mass-luminosity calibrations, the new distance implies the star is significantly more massive and so are the planet candidates. The same astrometric measurements allowed to constrain the orbital inclination and put an upper limit to the mass of Gliese 317 b (98% confidence level) of 2.5 M_jup.

The second planet in the system was also confirmed with the additional new RV measurements, but the period and orbital parameters of Gliese 317 c are still very uncertain (P>2000 days).[1] A stability analysis on this putative system suggest that the pair of gas giant planets are in a 4:1 mean motion resonance.[4]

The Gliese 317 planetary system[1]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b >1.81 ± 0.05 MJ 1.148 692.0 ± 2 0.11 ± 0.05
c (unconfirmed) ≥1.6 MJ ≥5.5 ≥7100 unknown

See also[edit]

References[edit]

  1. ^ a b c d e f g h Anglada-Escude, Guillem et al. (2012), "Astrometry and radial velocities of the planet host M dwarf Gliese 317: new trigonometric distance, metallicity and upper limit to the mass of Gliese 317 b", The Astrophysical Journal 764 (1): 37A, arXiv:1111.2623, Bibcode:2012ApJ...746...37A, doi:10.1088/0004-637X/746/1/37 
  2. ^ a b Terrien, Ryan C. et al, An H-band Spectroscopic Metallicity Calibration for M Dwarfs, arXiv:1202.1800, Bibcode:2012ApJ...747L..38T, doi:10.1088/2041-8205/747/2/L38 
  3. ^ a b Johnson, J. A. et al. (2007), "A New Planet Around an M Dwarf: Revealing a Correlation between Exoplanets and Stellar Mass", The Astrophysical Journal 670 (1): 833–840, arXiv:0707.2409, Bibcode:2007ApJ...670..833J, doi:10.1086/521720 
  4. ^ Rory Barnes; Richard Greenberg (2008). "Extrasolar Planet Interactions". arXiv:0801.3226v1 [astro-ph].

External links[edit]


Coordinates: Sky map 08h 40m 59.21s, −23° 27′ 22.6″