TOI-561

TOI-561
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Sextans
Right ascension 09h 52m 44.1851s[1]
Declination +06° 12′ 58.921″[1]
Apparent magnitude (V) 10.25[2]
Characteristics
Evolutionary stage main sequence
Spectral type G9V[2]
Astrometry
Proper motion (μ) RA: 124.612 mas/yr[1]
Dec.: −61.279 mas/yr[1]
Parallax (π)11.8342 ± 0.0208 mas[1]
Distance275.6 ± 0.5 ly
(84.5 ± 0.1 pc)
Details
Mass0.785±0.018[2] M☉
Radius0.849±0.007[2] R☉
Luminosity0.522±0.017[3] L☉
Surface gravity (log g)4.50±0.12[2] cgs
Temperature5,372±70[2] K
Metallicity [Fe/H]−0.40±0.05[2] dex
Rotational velocity (v sin i)<2[2] km/s
Age10±3[3] Gyr
Other designations
2MASS J09524454+0612589, TYC 243-1528-1, GSC 00243-01528, Gaia DR2 3850421005290172416
Database references
SIMBADdata

TOI-561 is an old, metal-poor, Sun-like star, known to have multiple small planets.[3][2][4][5] It is an orange dwarf, estimated to be 10.5 billion years old, and about 79% the mass and 85% the radius of Sol, Earth's sun.[6][5] It is located in the constellation Sextans, near the border with Leo.

In January 2021, a team led by Lauren Weiss of the University of Hawaii at Manoa announced that, using data from NASA's Transiting Exoplanet Survey Satellite, they had found a Super-Earth in a very close orbit, as well as two outer Sub-Neptunes.[7][8][6][3] The innermost planet, TOI-561 b, orbits in under one Earth day.[2][3] Another team led by Gaia Lacedelli of the University of Padua independently announced the discovery in a paper published in December 2020.[2] However, the two papers disagree on the structure of the system. While the innermost two planets were confirmed from data by both papers, Weiss proposes only a single third planet in a 16.3-day orbit, while Lacedelli argues that the system instead contains two further planets, in wider orbits of 25.6 and 77 days.[2]

  1. ^ a b c d Cite error: The named reference edr3 was invoked but never defined (see the help page).
  2. ^ a b c d e f g h i j k l Cite error: The named reference Lacedelli was invoked but never defined (see the help page).
  3. ^ a b c d e Cite error: The named reference Weiss2020 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference EPE was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference sci-news2021-01-13 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference sciencealert2021-01-14 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference UcRiverside2021-01-11 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference asiatatler2021-01-18 was invoked but never defined (see the help page).