TRAPPIST-1

TRAPPIST-1
TRAPPIST-1 lies in the northwestern part of the constellation Aquarius, close to the ecliptic.
TRAPPIST-1 is within the red circle in the constellation Aquarius.
Observation data
Epoch J2000      Equinox J2000
Constellation Aquarius
Right ascension 23h 06m 29.368s[1]
Declination −05° 02′ 29.04″[1]
Apparent magnitude (V) 18.798±0.082[2]
Characteristics
Evolutionary stage Main sequence
Spectral type M8V[3]
Apparent magnitude (R) 16.466±0.065[2]
Apparent magnitude (I) 14.024±0.115[2]
Apparent magnitude (J) 11.354±0.022[4]
Apparent magnitude (H) 10.718±0.021[4]
Apparent magnitude (K) 10.296±0.023[4]
V−R color index 2.332
R−I color index 2.442
J−H color index 0.636
J−K color index 1.058
Astrometry
Proper motion (μ) RA: 930.788[1] mas/yr
Dec.: −479.038[1] mas/yr
Parallax (π)80.2123 ± 0.0716 mas[1]
Distance40.66 ± 0.04 ly
(12.47 ± 0.01 pc)
Details
Mass0.0898±0.0023[5] M☉
Radius0.1192±0.0013[5] R☉
Luminosity (bolometric)0.000553±0.000018[5] L☉
Surface gravity (log g)5.2396+0.0056
−0.0073[a][5] cgs
Temperature2,566±26[5] K
Metallicity [Fe/H]0.04±0.08[6] dex
Rotation3.295±0.003 days[7]
Rotational velocity (v sin i)6[8] km/s
Age7.6±2.2[9] Gyr
Other designations
2MUDC 12171,[10] 2MASS J23062928–0502285, EPIC 246199087,[11] K2-112,[12] SPECULOOS-1,[b][13] TRAPPIST-1a[14]
Database references
SIMBADdata
Exoplanet Archivedata

TRAPPIST-1 is a cool red dwarf star[c] with seven known exoplanets. It lies in the constellation Aquarius about 40.66 light-years away from Earth, and has a surface temperature of about 2,566 K (2,290 °C; 4,160 °F). Its radius is slightly larger than Jupiter and it has a mass of about 9% of the Sun. It is estimated to be 7.6 billion years old, making it older than the Solar System. The discovery of the star was first published in 2000.

Observations in 2016 from the Transiting Planets and Planetesimals Small Telescope (TRAPPIST) at La Silla Observatory in Chile and other telescopes led to the discovery of two terrestrial planets in orbit around TRAPPIST-1. In 2017, further analysis of the original observations identified five more terrestrial planets. It takes the seven planets between about 1.5 and 19 days to orbit around the star in circular orbits. They are likely tidally locked to TRAPPIST-1, such that one side of each planet always faces the star, leading to permanent day on one side and permanent night on the other. Their masses are comparable to that of Earth and they all lie in the same plane; from Earth they seem to move past the disk of the star.

Up to four of the planets – designated d, e, f and g – orbit at distances where temperatures are suitable for the existence of liquid water, and are thus potentially hospitable to life. There is no evidence of an atmosphere on any of the planets, and observations of TRAPPIST-1 b have ruled out the existence of an atmosphere. It is unclear whether radiation emissions from TRAPPIST-1 would allow for such atmospheres. The planets have low densities; they may consist of large amounts of volatile materials. Due to the possibility of several of the planets being habitable, the system has drawn interest from researchers and has appeared in popular culture.

  1. ^ a b c d e Gaia EDR3 2021.
  2. ^ a b c Costa et al. 2006, p. 1240.
  3. ^ Costa et al. 2006, p. 1234.
  4. ^ a b c Cutri et al. 2003, p. II/246.
  5. ^ a b c d e Agol et al. 2021, p. 1.
  6. ^ Delrez et al. 2018, pp. 3577–3597.
  7. ^ Vida et al. 2017, p. 7.
  8. ^ Barnes et al. 2014, pp. 3094–3113.
  9. ^ Burgasser & Mamajek 2017, p. 7.
  10. ^ Martínez-Rodríguez et al. 2019, p. 3.
  11. ^ Turbet et al. 2020, p. 2.
  12. ^ Meadows & Schmidt 2020, p. 727.
  13. ^ Delrez et al. 2022, p. 2.
  14. ^ Harbach et al. 2021, p. 3.
  15. ^ Gargaud et al. 2011, Red Dwarf.


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