Gliese 754
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Telescopium
Right ascension 19h 20m 47.98349s[1]
Declination −45° 33′ 29.6292″[1]
Apparent magnitude (V) 12.25[2]
Characteristics
Spectral type M4V[2]
Astrometry
Radial velocity (Rv)+6.8[3] km/s
Proper motion (μ) RA: +659.330[1] mas/yr
Dec.: −2,897.035[1] mas/yr
Parallax (π)169.2351 ± 0.0588 mas[4]
Distance19.272 ± 0.007 ly
(5.909 ± 0.002 pc)
Details[3]
Mass0.173 M☉
Radius0.205 R☉
Luminosity0.005[5] L☉
Temperature3,202±100[6] K
Metallicity [Fe/H]−0.169[6] dex
Rotation132.651 days
Other designations
GJ 754, L 347-14, LHS 60, LTT 7652, 2MASS J19204795-4533283[7]
Database references
SIMBADdata
Gliese 754 is located in the constellation Telescopium
Gliese 754 is located in the constellation Telescopium
Gliese 754
Location of Gliese 754 in the constellation Telescopium

Gliese 754 is a dim star in the southern constellation of Telescopium. It has an apparent visual magnitude of 12.25,[2] which requires a telescope to view. The star is located at a distance of 19.3 light-years from the Sun based on parallax,[1] and it is drifting further away with a radial velocity of +7 km/s.[3] It is one of the hundred closest stars to the Solar System. Calculations of its orbit around the Milky Way showed that it is eccentric, and indicate that it might be a thick disk object.[8]

The stellar classification of Gliese 754 is M4V,[2] indicating that this is a small red dwarf star on the core hydrogen fusing main sequence. It has 17% of the mass of the Sun and 21% of the Sun's radius.[3] The star is fully convective and is a source of X-ray emission.[9] It is rotating slowly with a period of about 133 days.[3] The metallicity is sub-solar,[6] indicating it has a lower abundance of heavy elements compared to the Sun. It is radiating just 0.5%[5] of the luminosity of the Sun from its photosphere at an effective temperature of around 3,202 K.[6]

Planetary System

In June 2019, a candidate exoplanet was reported in orbit around Gliese 754. It was detected using the Doppler method and is orbiting at a distance of 0.28 AU with a period of 78 days. The orbit is essentially circular, to within the margin of error.[10] The habitable zone for this star ranges from 0.05 AU to 0.14 AU;[5] inside the orbit of this proposed companion.

The Gliese 754 planetary system
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(days) 		Eccentricity Inclination Radius
b (unconfirmed) ≥9.8+4.6
−5.2 M⊕ 		0.277+0.025
−0.028 		78.37+0.55
−0.47 		0.03+0.20
−0.03 		— —

References

  1. ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. ^ a b c d Henry, Todd J.; et al. (2018). "The Solar Neighborhood XLIV: RECONS Discoveries within 10 parsecs". The Astronomical Journal. 155 (6): 265. arXiv:1804.07377. Bibcode:2018AJ....155..265H. doi:10.3847/1538-3881/aac262. S2CID 53983430.
  3. ^ a b c d e Newton, Elisabeth R.; et al. (November 2018). "New Rotation Period Measurements for M Dwarfs in the Southern Hemisphere: An Abundance of Slowly Rotating, Fully Convective Stars". The Astronomical Journal. 156 (5): 11. arXiv:1807.09365. Bibcode:2018AJ....156..217N. doi:10.3847/1538-3881/aad73b. S2CID 119209638. 217.
  4. ^ 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.
  5. ^ a b c Mayor, M.; et al. (2009). "The HARPS search for southern extra-solar planets. XIII. A planetary system with 3 Super-Earths (4.2, 6.9, & 9.2 Earth masses)". Astronomy and Astrophysics. 493 (2): 639–644. arXiv:0806.4587. Bibcode:2009A&A...493..639M. doi:10.1051/0004-6361:200810451. S2CID 116365802.
  6. ^ a b c d Houdebine, E. R.; et al. (May 2016). "Rotation-Activity Correlations in K and M Dwarfs. I. Stellar Parameters and Compilations of v sin I and P/sin I for a Large Sample of Late-K and M Dwarfs". The Astrophysical Journal. 822 (2): 38. arXiv:1604.07920. Bibcode:2016ApJ...822...97H. doi:10.3847/0004-637X/822/2/97. S2CID 119118088. 97.
  7. ^ "L 347-14". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-12-12.
  8. ^ Innanen, K.A.; Flynn, C. (2010). "The Radial Velocity, Space Motion, and Galactic Orbit of GJ 754". Journal of the Royal Astronomical Society of Canada. 104 (6): 223–24. Bibcode:2010JRASC.104..223I.
  9. ^ Wright, Nicholas J.; et al. (September 2018). "The stellar rotation-activity relationship in fully convective M dwarfs". Monthly Notices of the Royal Astronomical Society. 479 (2): 2351–2360. arXiv:1807.03304. Bibcode:2018MNRAS.479.2351W. doi:10.1093/mnras/sty1670.
  10. ^ Barnes, J. R.; et al. (June 2019). "Frequency of planets orbiting M dwarfs in the Solar neighbourhood". arXiv:1906.04644. Bibcode:2019arXiv190604644T. ((cite journal)): Cite journal requires |journal= (help)
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