Wikipedia
HD 27894
HD 27894 is a 9th magnitude star located approximately 143 light years away in the constellation of Reticulum. It is an orange dwarf (spectral type K2V), a type dimmer and cooler than the Sun.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Reticulum |
| Right ascension | 04h 20m 47.046106s[1] |
| Declination | −59° 24′ 39.024641″[1] |
| Apparent magnitude (V) | 9.42 |
| Characteristics | |
| Spectral type | K2 V[2] |
| U−B color index | +0.90[3] |
| B−V color index | +1.005[3] |
| Astrometry | |
| Radial velocity (Rv) | 82.74±0.15[1] km/s |
| Proper motion (μ) | RA: 182.473±0.012 mas/yr[1] Dec.: 270.012±0.017 mas/yr[1] |
| Parallax (π) | 22.8888 ± 0.0121 mas[1] |
| Distance | 142.50 ± 0.08 ly (43.69 ± 0.02 pc) |
| Details | |
| Mass | 0.86 ± 0.06[4] M☉ |
| Surface gravity (log g) | 4.54 ± 0.05[4] cgs |
| Temperature | 4920 ± 45[4] K |
| Metallicity [Fe/H] | +0.20[5] dex |
| Age | 7.7 ± 2.3[4] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
In 2005, the Geneva Extrasolar Planet Search Team announced the discovery of an extrasolar planet orbiting the star.[6] In 2017, the discovery of two additional exoplanets was announced. One is very close to the star like the one discovered earlier, while the other one orbits the star at a much larger distance. It is the first system where such a large gap between orbital distances has been found.[7][8] In 2022, the inclination and true mass of HD 27894 d were measured via astrometry. The study only found strong evidence for planets b and d.[9]
| Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥0.665+0.009 −0.007 MJ | 0.125±0.0001 | 18.02+0.01 −0.02 | 0.047+0.012 −0.008 | — | — |
| c | ≥0.162+0.011 −0.040 MJ | 0.198±0.001 | 36.07+0.26 −0.09 | 0.015+0.020 −0.002 | — | — |
| d | 6.493+0.987 −0.353 MJ | 5.362+0.206 −0.223 | 5019.5+32.6 −31.1 | 0.343+0.031 −0.026 | 101.524+14.742 −31.503° | — |
See also edit
References edit
- ^ a b c d e 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.
- ^ Houk, Nancy (1979). Michigan catalogue of two-dimensional spectral types for the HD stars. Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan. Bibcode:1978mcts.book.....H. LCCN 78010745.
- ^ a b c "LTT 1953 -- High proper-motion Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2012-02-05
- ^ a b c d Trevisan, M.; et al. (November 2011), "Analysis of old very metal rich stars in the solar neighbourhood", Astronomy & Astrophysics, 535: A42, arXiv:1109.6304, Bibcode:2011A&A...535A..42T, doi:10.1051/0004-6361/201016056, S2CID 49565866. See table 13.
- ^ Sousa, S. G.; et al. (August 2008), "Spectroscopic parameters for 451 stars in the HARPS GTO planet search program. Stellar [Fe/H] and the frequency of exo-Neptunes", Astronomy and Astrophysics, 487 (1): 373–381, arXiv:0805.4826, Bibcode:2008A&A...487..373S, doi:10.1051/0004-6361:200809698, S2CID 18173201
- ^ Moutou, C.; et al. (2005). "The HARPS search for southern extra-solar planets IV. Three close-in planets around HD 2638, HD 27894 and HD 63454". Astronomy and Astrophysics. 439 (1): 367–373. Bibcode:2005A&A...439..367M. doi:10.1051/0004-6361:20052826.
- ^ a b Trifonov, T.; Kürster, M.; Zechmeister, M.; Zakhozhay, O. V.; Reffert, S.; Lee, M. H.; Rodler, F.; Vogt, S. S.; Brems, S. S. (2017). "Three planets around HD 27894. A close-in pair with a 2:1 period ratio and an eccentric Jovian planet at 5.4 AU". Astronomy & Astrophysics. 602: L8. arXiv:1706.00509. Bibcode:2017A&A...602L...8T. doi:10.1051/0004-6361/201731044. S2CID 119105619.
- ^ Tomasz Nowakowski (June 12, 2017). "Two new massive planets detected around the star HD 27894". Retrieved June 12, 2017.
- ^ a b Feng, Fabo; Butler, R. Paul; et al. (August 2022). "3D Selection of 167 Substellar Companions to Nearby Stars". The Astrophysical Journal Supplement Series. 262 (21): 21. arXiv:2208.12720. Bibcode:2022ApJS..262...21F. doi:10.3847/1538-4365/ac7e57. S2CID 251864022.