Astronomy:Theta Reticuli
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Reticulum |
| Right ascension | 04h 17m 40.27169s[1] |
| Declination | −63° 15′ 19.4882″[1] |
| Apparent magnitude (V) | 5.88[2] 6.05 + 7.65[3] |
| Characteristics | |
| θ Ret A | |
| Spectral type | B9IV[4] |
| B−V color index | −0.09[3] |
| Variable type | suspected[5] |
| θ Ret B | |
| Spectral type | kA2hA5VmA7[4] |
| B−V color index | +0.14[3] |
| Astrometry | |
| θ Ret A | |
| Radial velocity (Rv) | 3.0±7.4[2] km/s |
| Proper motion (μ) | RA: +6.273[1] mas/yr Dec.: +35.360[1] mas/yr |
| Parallax (π) | 7.0053 ± 0.0401[1] mas |
| Distance | 466 ± 3 ly (142.7 ± 0.8 pc) |
| Absolute magnitude (MV) | −0.04[6] |
| θ Ret B | |
| Proper motion (μ) | RA: +8.512[7] mas/yr Dec.: +35.235[7] mas/yr |
| Parallax (π) | 7.1837 ± 0.0540[7] mas |
| Distance | 454 ± 3 ly (139 ± 1 pc) |
| Details | |
| θ Ret A | |
| Mass | 3.363±0.117[6] M☉ |
| Luminosity | 179[6] L☉ |
| Temperature | 11,967[6] K |
| Rotation | 2.9686[8] d |
| Age | 166[6] Myr |
| θ Ret B | |
| Mass | ≥ 1.18[6] M☉ |
| Temperature | 9,132[7] K |
| Age | 200[4] Myr |
| Other designations | |
| θ Ret A: {{{names1}}} | |
| θ Ret B: {{{names2}}} | |
| Database references | |
| SIMBAD | data |
| A | |
| B | |
Theta Reticuli is double star in southern constellation of Reticulum, located just 50′ south of Alpha Reticuli.[10] The pair are visible to the naked eye as a dim, white-hued point of light with a combined apparent visual magnitude of 5.88.[2] They lie at roughly the same distance from the Sun based on parallax, with the primary being around 466 light-years away. They also share a similar proper motion,[1][7] suggesting they may be gravitationally bound.[11]
The magnitude 6.05[3] primary, designated component A, has a stellar classification of B9IV,[4] matching a B-type subgiant. It is 166 million years old with 3.4 times the mass of the Sun. The star is radiating 179 times the Sun's luminosity from its photosphere at an effective temperature of 11,967 K.[6]
As of 2015, the magnitude 7.65[3] secondary, component B, had an angular separation of 4.10″ from the primary along a position angle of 3°.[12] It is most likely a very young main-sequence star,[6] and is an Am star with a stellar classification of kA2hA5VmA7.[4] This notation indicates the spectrum displays the K-line of an A2-type star, the hydrogen lines of a cooler A5 star, and the metal lines of an A7 star. This system is a source of X-ray emission, which may be coming from the companion.[6]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 3.2 3.3 3.4 Høg, E. et al. (2000), "The Tycho-2 catalogue of the 2.5 million brightest stars", Astronomy and Astrophysics 355: L27, doi:10.1888/0333750888/2862, ISBN 978-0333750889, Bibcode: 2000A&A...355L..27H.
- ↑ 4.0 4.1 4.2 4.3 4.4 Corbally, C. J. (1984), "Close visual binaries. I - MK classifications", Astrophysical Journal Supplement Series 55: 657, doi:10.1086/190973, Bibcode: 1984ApJS...55..657C.
- ↑ Samus, N. N. et al. (2009), "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)", VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S 1: B/gcvs, Bibcode: 2009yCat....102025S.
- ↑ 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 Hubrig, S. et al. (June 2001), "Search for low-mass PMS companions around X-ray selected late B stars", Astronomy and Astrophysics 372: 152–164, doi:10.1051/0004-6361:20010452, Bibcode: 2001A&A...372..152H.
- ↑ 7.0 7.1 7.2 7.3 7.4 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ Barraza, L. F.; Gomes, R. L.; Messias, Y. S.; Leão, I. C.; Almeida, L. A.; Janot-Pacheco, E.; Brito, A. C.; Brito, F. A. C. et al. (2022). "Rotation Signature of TESS B-type Stars. A Comprehensive Analysis". The Astrophysical Journal 924 (2): 117. doi:10.3847/1538-4357/ac3335. Bibcode: 2022ApJ...924..117B.
- ↑ "tet Ret". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=tet+Ret.
- ↑ Streicher, Magda (December 2009), "Reticulum: The Celestial Crosshairs", Monthly Notes of the Astronomical Society of South Africa 68 (11 and 12): 242–246, Bibcode: 2009MNSSA..68..242S.
- ↑ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869–879, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ Mason, B. D. et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal 122 (6): 3466, doi:10.1086/323920, Bibcode: 2001AJ....122.3466M.
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