TOI-178

TOI-178
Observation data
Epoch J2000      Equinox J2000
Constellation Sculptor
Right ascension 00h 29m 12.30s[1]
Declination −30° 27′ 13.46″[1]
Apparent magnitude (V) 11.95[1]
Characteristics
Evolutionary stage Main sequence
Spectral type K7V[1]
Astrometry
Radial velocity (Rv)57.4±0.5[1] km/s
Proper motion (μ) RA: 149.95±0.07[1] mas/yr
Dec.: −87.25±0.04[1] mas/yr
Parallax (π)15.92 ± 0.05 mas[1]
Distance204.9 ± 0.6 ly
(62.8 ± 0.2 pc)
Details
Mass0.650+0.027
−0.029[1] M☉
Radius0.651±0.011[1] R☉
Luminosity (bolometric)0.132±0.010[1] L☉
Surface gravity (log g)4.45±0.15[1] cgs
Temperature4316±70[1] K
Metallicity [Fe/H]−0.23±0.05[1] dex
Rotational velocity (v sin i)1.5±0.3[1] km/s
Other designations
2MASS J00291228-3027133, Gaia DR2 2318295979126499200, TIC 251848941, TYC 6991-00475-1
Database references
SIMBADdata

TOI-178 is a planetary system in the constellation Sculptor[2] around which six planets have been observed, at at least five of which orbit in a chain of Laplace resonances, which constitute one of the longest chains yet discovered in a system of planets. The system also has unusual variations in the densities among the planets.[3][4][1]

The system is 205 light-years away, which is relatively close, implying that such systems may be relatively common.[4][3] The brightness of the star, TOI-178, facilitates followup observations, which make it an ideal system in which to expand our understanding of planet formation and evolution.[1]

The planetary system was confirmed by data provided by five different planet search projects. After TESS provided first hints at a system with an interesting resonant chain, additional observations to refine the measurement and confirm the finding were provided by CHEOPS, ESPRESSO, NGTS and SPECULOOS. Over the coming years, observations of transit-timing variations in the transits of the various planets, which are expected to range from minutes to tens of minutes, should help pin down the planetary masses and uncover the eccentricities of the various orbits.[1]

  1. ^ a b c d e f g h i j k l m n o p q r Leleu, A.; Alibert, Y.; Hara, N. C.; Hooton, M. J.; Wilson, T. G.; Robutel, P.; Delisle, J.-B.; Laskar, J.; Hoyer, S.; Lovis, C.; Bryant, E. M.; Ducrot, E.; Cabrera, J.; Delrez, L.; Acton, J. S.; Adibekyan, V.; Allart, R.; Prieto, Allende; Alonso, R.; Alves, D.; et al. (2021-01-20). "Six transiting planets and a chain of Laplace resonances in TOI-178". Astronomy & Astrophysics. 649: A26. arXiv:2101.09260. Bibcode:2021A&A...649A..26L. doi:10.1051/0004-6361/202039767. ISSN 0004-6361. S2CID 231693292.
  2. ^ Roman, Nancy G. (1987). "Identification of a Constellation From a Position". Publications of the Astronomical Society of the Pacific. 99 (617): 695–699. Bibcode:1987PASP...99..695R. doi:10.1086/132034. S2CID 120559848.. Requête spécifique à TOI-178 sur VizieR.
  3. ^ a b Plait, Phil (2021-01-25). "A six-planet system dances in time to the tune of gravity". SYFY WIRE. Retrieved 2021-01-27.
  4. ^ a b "Nearby Orange Dwarf Hosts Unique System of Six Planets | Astronomy | Sci-News.com". Breaking Science News | Sci-News.com. Retrieved 2021-01-27.