HD 27894
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Reticulum |
Right ascension | 04h 20m 47.04716s[1] |
Declination | –59° 24′ 39.0184″[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 | |
Proper motion (μ) | RA: +182.16[1] mas/yr Dec.: +271.77[1] mas/yr |
Parallax (π) | 22.79 ± 0.85[1] mas |
Distance | 143 ± 5 ly (44 ± 2 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 |
HD 27894 is a 9th magnitude star located approximately 138 light years away in the constellation of Reticulum. It is an orange dwarf (spectral type K2V), a type dimmer and cooler than our Sun.
In 2005, the Geneva Extrasolar Planet Search Team announced some of the discoveries 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]
Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | >0.66 MJ | 0.125 | 18.02 ± 0.02 | 0.047 ± 0.010 | — | — |
c | >0.16 MJ | 0.198 | 36.1 ± 0.2 | 0.02 ± 0.02 | — | — |
d | >5.4 MJ | 5.4 | 5200 ± 100 | 0.39 ± 0.05 | — | — |
See also
References
- 1 2 3 4 5 van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357
- ↑ 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.
- 1 2 3 "LTT 1953 -- High proper-motion Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2012-02-05
- 1 2 3 4 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 . 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
- 1 2 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. arXiv:1411.7048. Bibcode:2005A&A...439..367M. doi:10.1051/0004-6361:20052826.
- ↑ 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 [astro-ph.EP]. Bibcode:2017A&A...602L...8T. doi:10.1051/0004-6361/201731044. Cite uses deprecated parameter
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(help) - ↑ Tomasz Nowakowski (June 12, 2017). "Two new massive planets detected around the star HD 27894". Retrieved June 12, 2017.
External links
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