LHS 1140

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LHS 1140
Artist’s impression of the super-Earth exoplanet LHS 1140b.jpg
Artist's impression of LHS 1140 and LHS 1140b.
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cetus
Right ascension 00h 44m 59.31s[1]
Declination −15° 16′ 16.7″[1]
Apparent magnitude (V) 14.18[2]
Characteristics
Evolutionary stage Red dwarf
Spectral type M4.5V[2]
Astrometry
Radial velocity (Rv)-13.23 ± 0.60[2] km/s
Proper motion (μ) RA: 317[3] mas/yr
Dec.: -589[3] mas/yr
Distance40.67 ± 1.37 ly
(12.47 ± 0.42[2] pc)
Details[2]
Mass0.146 ± 0.009 M
Radius0.186 ± 0.013 R
Luminosity0.002981 ± 0.00021 L
Temperature3131 ± 100 K
Metallicity [Fe/H]-0.24 ± 0.10 dex
Rotation131 d
Age>5 Gyr
Other designations
GJ 3053, G 270-58, G 268-38, 2MASS J00445930-1516166
Database references
SIMBADdata
ARICNSdata

LHS 1140 is a red dwarf in the constellation of Cetus. Based on its stellar properties, it is thought to be about 41 light-years away from the Sun.[2] 'LHS' refers to the Luyten Half-Second Catalogue of stars with proper motions exceeding half a second of arc annually.[4] The star is over 5 billion years old and has 15% of the mass of the Sun. LHS 1140's rotational period is 130 days. No flares have been observed.[5]

LHS 1140 has a rocky planet, LHS 1140 b, orbiting it. The planet is a super-Earth in a habitable zone and transits the star. This should allow its atmosphere to be studied in future: the combination of the transiting super-Earth and the relatively small and nearby host star make this system one of the most promising known for atmosphere studies, along with the TRAPPIST-1 system. The mass of LHS 1140b is 6.7 ± 1.8 times Earth's and its radius is 1.4 ± 0.1 times as large,[2][6] giving it a density roughly 2.3 ± 0.6 times that of Earth or 12.5 g/cm3.[2]

In July 2018, two new likely planet candidates were found by Fabo Feng, Mikko Tuomi, and Hugh R. A. Jones: an Earth-mass planet orbiting every 3.8 days and a Neptune-mass planet orbiting every 90 days.[7]

The LHS 1140 planetary system[2][7]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
d (candidate) 1.57-1.96 M 0.025 3.78 0.07-0.19 ~90°
b 6.65 ± 1.82 M 0.0875 24.73712 ± 0.00025 <0.29 89.912 ± 0.071° 1.43 ± 0.10 R
c (candidate) 9.64-11.11 M 0.210 92-93 0-0.03 ~90°

The orbit of LHS 1140b is nearly circular with a radius of 0.09 AU. LHS 1140b orbits and transits the star every 24.7 days.[2] The planet was discovered in 2017 by the MEarth Project. Radial velocities were measured by High Accuracy Radial Velocity Planet Searcher.[5]


See also[edit]

References[edit]

  1. ^ a b Cutri, R. M.; et al. (2003). "2MASS All-Sky Catalog of Point Sources". VizieR On-line Data Catalog. 2246. Bibcode:2003yCat.2246....0C. 
  2. ^ a b c d e f g h i j Dittmann, Jason A.; Irwin, Jonathan M.; Charbonneau, David; Bonfils, Xavier; Astudillo-Defru, Nicola; Haywood, Raphaëlle D.; Berta-Thompson, Zachory K.; Newton, Elisabeth R.; Rodriguez, Joseph E.; Winters, Jennifer G.; Tan, Thiam-Guan; Almenara, Jose-Manuel; Bouchy, François; Delfosse, Xavier; Forveille, Thierry; Lovis, Christophe; Murgas, Felipe; Pepe, Francesco; Santos, Nuno C.; Udry, Stephane; Wünsche, Anaël; Esquerdo, Gilbert A.; Latham, David W.; Dressing, Courtney D. (2017). "A temperate rocky super-Earth transiting a nearby cool star". Nature. 544 (7650): 333. arXiv:1704.05556Freely accessible. Bibcode:2017Natur.544..333D. doi:10.1038/nature22055. PMID 28426003. 
  3. ^ a b Salim, Samir; Gould, Andrew (2003). "Improved Astrometry and Photometry for the Luyten Catalog. II. Faint Stars and the Revised Catalog". The Astrophysical Journal. 582 (2): 1011. arXiv:astro-ph/0206318Freely accessible. Bibcode:2003ApJ...582.1011S. doi:10.1086/344822. 
  4. ^ Luyten, Willem Jacob, Catalogue of stars with proper motions exceeding 0"5 annually, University of Minnesota, 1979
  5. ^ a b Dickinson, David (19 April 2017). "Welcome to LHS 1140b: A Super-Earth in the Habitable Zone". Sky & Telescope. Retrieved 19 April 2017. 
  6. ^ Overbye, Dennis (19 April 2017). "A New Exoplanet May Be Most Promising Yet in Search for Life". New York Times. Retrieved 20 April 2017. 
  7. ^ a b https://arxiv.org/pdf/1807.02483.pdf