Gliese 555
Gliese 555, also known as HN Librae, is a red dwarf star of spectral type M4.0V, located in the constellation Libra at a distance of 20.4 light-years (6.3 parsecs) from Earth.[2]
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Libra |
Right ascension | 14h 34m 16.81166s[2] |
Declination | −12° 31′ 10.4145″[2] |
Apparent magnitude (V) | 11.317 |
Characteristics | |
Spectral type | M4.0V[3] |
Variable type | BY Dra |
Astrometry | |
Radial velocity (Rv) | −1.36±0.20[2] km/s |
Proper motion (μ) | RA: −355.138 mas/yr[2] Dec.: 593.040 mas/yr[2] |
Parallax (π) | 159.9225 ± 0.0546 mas[2] |
Distance | 20.395 ± 0.007 ly (6.253 ± 0.002 pc) |
Details[3] | |
Mass | 0.291±0.013 M☉ |
Radius | 0.299±0.009 R☉ |
Luminosity (bolometric) | 0.010106±0.000069 L☉ |
Surface gravity (log g) | 4.76±0.13 cgs |
Temperature | 3347±50 K |
Metallicity [Fe/H] | −0.18±0.15 dex |
Rotation | 96±2 d |
Rotational velocity (v sin i) | <2.0 km/s |
Age | 0.8–8.0 Gyr |
Other designations | |
Database references | |
SIMBAD | data |
![]() ![]() Gliese 555 Location of Gliese 555 in the constellation Libra |
Planetary system
In 2019, one planet candidate detected by radial velocity was reported in a preprint, among 118 planets around M dwarf stars. This would have a minimum mass about 30 times that of Earth and orbit with a period of about 450 days.[14]
However, later radial velocity observations by the CARMENES survey published in 2023 did not confirm a planet at this period, but instead found a different planet.[15] This is a super-Earth or mini-Neptune (the discovery paper uses the term "sub-Neptune") with a minimum mass of 5.5 Earths and a period of 36 days, placing it within the habitable zone. A second planet candidate was also found, with a minimum mass of 9.7 Earths and a period of 113 days, but this signal could not be confirmed as having a planetary origin due to its similarity to the rotation period of the star.[3]
Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | ≥5.46±0.75 M🜨 | 0.1417±0.0023 | 36.116+0.027 −0.029 |
0.079+0.090 −0.055 |
— | — |
c (unconfirmed) | ≥9.7±1.9 M🜨 | 0.3040+0.0048 −0.0051 |
113.46+0.19 −0.20 |
— | — | — |
References
- Weis, Edward W. (March 1994). "Long Term Variability in Dwarf M Stars". The Astronomical Journal. 107: 1135–1140. Bibcode:1994AJ....107.1135W. doi:10.1086/116925. Retrieved 20 January 2022.
- Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- González-Álvarez, E.; Kemmer, J.; et al. (July 2023). "The CARMENES search for exoplanets around M dwarfs. A sub-Neptunian mass planet in the habitable zone of HN Lib". Astronomy & Astrophysics. 675: A141. arXiv:2305.19677. Bibcode:2023A&A...675A.141G. doi:10.1051/0004-6361/202346276.
- Schönfeld, Eduard; et al. (1886). "BD -11 3759". Southern Durchmusterung.
- Gliese, W.; Jahreiß, H. (1991). "Gl 555". Preliminary Version of the Third Catalogue of Nearby Stars.
- Perryman; et al. (1997). "HIP 71253". The Hipparcos and Tycho Catalogues.
- Porter, J. G.; Yowell, E. J.; Smith, E. S. (1930). "A catalogue of 1474 stars with proper motion exceeding four-tenths year". Publications of the Cincinnati Observatory. 20: 1–32. Bibcode:1930PCinO..20....1P. Page 20 (Ci 20 870).
- Luyten, Willem Jacob (1979). "LHS 2945". LHS Catalogue, 2nd Edition.
- Luyten, Willem Jacob (1979). "NLTT 37751". NLTT Catalogue.
- Van Altena W. F.; Lee J. T.; Hoffleit E. D. (1995). "GCTP 3296". The General Catalogue of Trigonometric Stellar Parallaxes (Fourth ed.).
- Wolf, M. (1925). "Einige bewegte Sterne in Virgo und Libra". Astronomische Nachrichten. 225 (12): 215–216. Bibcode:1925AN....225R.215W. doi:10.1002/asna.19252251205. Page 215/216 (Wolf 1481)
- Perryman; et al. (1997). "HIP 71253". The Hipparcos and Tycho Catalogues.
- Hog; et al. (2000). "TYC 5572-804-1". The Tycho-2 Catalogue.
- Barnes, J. R.; Kiraga, M.; Diaz, M.; Berdiñas, Z.; Jenkins, J. S.; Keiser, S.; Thompson, I.; Crane, J. D.; Shectman, S. A. (2019-06-11). "Frequency of planets orbiting M dwarfs in the Solar neighbourhood". arXiv:1906.04644 [astro-ph.EP].
- Ribas, I.; Reiners, A.; et al. (February 2023). "The CARMENES search for exoplanets around M dwarfs. Guaranteed time observations Data Release 1 (2016-2020)". Astronomy & Astrophysics. 670: A139. arXiv:2302.10528. Bibcode:2023A&A...670A.139R. doi:10.1051/0004-6361/202244879.