Astronomy:Beta Circini
  | |
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Circinus |
| Right ascension | 15h 17m 30.84945s[1] |
| Declination | −58° 48′ 04.3453″[1] |
| Apparent magnitude (V) | 4.069[2] |
| Characteristics | |
| Spectral type | A3 Va[2] |
| U−B color index | +0.09[3] |
| B−V color index | +0.09[3] |
| Astrometry | |
| Radial velocity (Rv) | 9.6±2[2] km/s |
| Proper motion (μ) | RA: −97.182[1] mas/yr Dec.: −136.055[1] mas/yr |
| Parallax (π) | 35.8205 ± 0.2515[1] mas |
| Distance | 91.1 ± 0.6 ly (27.9 ± 0.2 pc) |
| Absolute magnitude (MV) | +1.64[4] |
| Details | |
| Mass | 1.96+0.03 −0.01[5] M☉ |
| Radius | 1.92[6] R☉ |
| Luminosity | 19[4] L☉ |
| Surface gravity (log g) | 4.281[7] cgs |
| Temperature | 8676±33[5] K |
| Metallicity [Fe/H] | 0.16[4] dex |
| Rotational velocity (v sin i) | 59[3] km/s |
| Age | 370–500[5] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Beta Circini, Latinized from β Circini, is an A-type main sequence star and is the second-brightest star in the constellation of Circinus.[2] It has an apparent visual magnitude of approximately 4.069,[2] which is bright enough to be viewed with the naked eye. Based upon an annual parallax shift of 35.8 mas as seen from the Earth, it is located 91 light years from the Sun.
With a stellar classification of A3 Va,[2] this is an main-sequence star fusing atoms of hydrogen into helium at its core. It is between 370 and 500 million years old[5] with around 1.9[6] times the Sun's radius. The star is radiating 19[4] times the Sun's luminosity from its photosphere at an effective temperature of 8,676 K.[5] It has one known sub-stellar companion.
Substellar companion
Beta Circini b is a distant brown dwarf companion orbiting the host star at a distance of 6,656 AU. It was detected as a proper motion companion to Beta Circini in 2015 by L.C. Smith and collaborators. Using BHAC15 isochrones, its mass is estimated at 0.056 M☉, or 59 MJ. It has a stellar classification of L1 and a temperature of 2,084 K (1,811 °C).[5]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 58.7±7.3 MJ | 6,656 | — | — | — | — |
References
- ↑ 1.0 1.1 1.2 1.3 1.4 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.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 "* bet Cir". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+bet+Cir.
- ↑ 3.0 3.1 3.2 HR 5670, database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50. Accessed on line September 5, 2008.
- ↑ 4.0 4.1 4.2 4.3 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 Smith, L. C. et al. (2015). "Discovery of a brown dwarf companion to the A3V star β Circini". Monthly Notices of the Royal Astronomical Society 454 (4): 4476–4483. doi:10.1093/mnras/stv2290. Bibcode: 2015MNRAS.454.4476S. https://academic.oup.com/mnras/article/454/4/4476/1003701.
- ↑ 6.0 6.1 Cotten, Tara H.; Song, Inseok (2016-07-01). "A Comprehensive Census of Nearby Infrared Excess Stars". The Astrophysical Journal Supplement Series 225 (1): 15. doi:10.3847/0067-0049/225/1/15. ISSN 0067-0049. Bibcode: 2016ApJS..225...15C. Beta Circini's database entry at VizieR.
- ↑
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