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.

HD 27894
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]
Distance142.50 ± 0.08 ly
(43.69 ± 0.02 pc)
Details
Mass0.86 ± 0.06[4] M☉
Surface gravity (log g)4.54 ± 0.05[4] cgs
Temperature4920 ± 45[4] K
Metallicity [Fe/H]+0.20[5] dex
Age7.7 ± 2.3[4] Gyr
Other designations
CD−59° 829, HD 27894, HIP 20277, LTT 1953.[3]
Database references
SIMBADdata

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]

The HD 27894 planetary system[7][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

References
  1. 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.
  2. 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.
  3. "LTT 1953 -- High proper-motion Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2012-02-05
  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, S2CID 49565866. See table 13.
  5. 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
  6. 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.
  7. 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.
  8. Tomasz Nowakowski (June 12, 2017). "Two new massive planets detected around the star HD 27894". Retrieved June 12, 2017.
  9. 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.


This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.