Astronomy:h Orionis
h Orionis is a binary star in the constellation Orion. At an apparent magnitude of +5.43, it is faintly visible to the naked eye in locations far from light pollution. Parallax measurements give a distance of 174 light-years (53.3 parsecs).
Characteristics
This is a single-lined spectroscopic binary,[5] first spotted in 1969 by Peter S. Conti.[10] The components take 155.87 days to orbit around each other, following a moderately-eccentric path with an eccentricity of 0.553 and a semi-major axis of 0.75 astronomical units.[6]
The primary is an A or F-type star and an Am star,[6] with its spectrum matching a spectral class of kA2hF1mF3.[3] The star has 1.76 times the mass of the Sun and 2.2 times the Sun's radius. It has an effective temperature of 7,500 K,[6] which gives it the white hue typical of an A or early F-type star.[11]
The secondary is a red dwarf with about half the size of the Sun and an effecitve temperature of 3,900 K.[6]
h Orionis has been suspected to be a member of the Hyades cluster based on its stellar kinematics. However, the estimated age of the system, 1.12 billion years, is almost twice that of the cluster. The red dwarf also does not emit the amount of X-rays expected for an object of the Hyades' age, further arguing against the system's membership of the cluster.[6]
References
- ↑ 1.0 1.1 1.2 1.3 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A XHIP record for this object at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 3.0 3.1 Abt, H. A.; Levy, S. G. (1985). "Improved study of metallic-line binaries". The Astrophysical Journal Supplement Series 59: 229. doi:10.1086/191070. Bibcode: 1985ApJS...59..229A.
- ↑ Leão, I. C.; Pasquini, L.; Ludwig, H.-G.; De Medeiros, J. R. (2019). "Spectroscopic and astrometric radial velocities: Hyades as a benchmark". Monthly Notices of the Royal Astronomical Society 483 (4): 5026. doi:10.1093/mnras/sty3215. Bibcode: 2019MNRAS.483.5026L.
- ↑ 5.0 5.1 Torres, Guillermo; Stefanik, Robert P.; Latham, David W. (2026). "Long-term Spectroscopic Survey of the Hyades Cluster: The Binary Population". The Astrophysical Journal Supplement Series 283 (2): 81. doi:10.3847/1538-4365/ae4fbb. Bibcode: 2026ApJS..283...81T. Table with properties, entry 575.
- ↑ 6.00 6.01 6.02 6.03 6.04 6.05 6.06 6.07 6.08 6.09 6.10 6.11 6.12 6.13 6.14 Waisberg, Idel; Klein, Ygal; Katz, Boaz (2026). "Hidden Companions to Intermediate-mass Stars. XXXVII. Uncovering a 0.53M⊙, 0.75 au Companion to h Orionis". Research Notes of the American Astronomical Society 10 (5): 125. doi:10.3847/2515-5172/ae6eec. Bibcode: 2026RNAAS..10..125W.
- ↑ 7.0 7.1 Stassun, Keivan G. et al. (2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal 158 (4): 138. doi:10.3847/1538-3881/ab3467. Bibcode: 2019AJ....158..138S.
- ↑ 8.0 8.1 Takeda, Yoichi; Han, Inwoo; Kang, Dong-Il; Lee, Byeong-Cheol; Kim, Kang-Min (2019). "Compositional differences between the component stars of eclipsing close binary systems showing chemical peculiarities". Monthly Notices of the Royal Astronomical Society 485 (1): 1067. doi:10.1093/mnras/stz449. Bibcode: 2019MNRAS.485.1067T.
- ↑ "16 Ori". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=16+Ori.
- ↑ Conti, Peter S. (1969). "Zeeman Observations of Metallic-Line Stars" (in en). The Astrophysical Journal 156: 661. doi:10.1086/149996. ISSN 0004-637X. Bibcode: 1969ApJ...156..661C.
- ↑ "The Colour of Stars". Australia Telescope, Outreach and Education. Commonwealth Scientific and Industrial Research Organisation. December 21, 2004. http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html. Retrieved 2012-01-16.
Coordinates:
05h 09m 19.643s, +09° 49′ 46.50″
