47 Capricorni
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Capricornus |
| Right ascension | 21h 46m 16.26887s[2] |
| Declination | −09° 16′ 33.3799″[2] |
| Apparent magnitude (V) | 6.00[3] (5.90 - 6.14)[4] |
| Characteristics | |
| Evolutionary stage | giant |
| Spectral type | M2III[5] |
| B−V color index | 1.629±0.010[3] |
| Variable type | SRb[4] |
| Astrometry | |
| Radial velocity (Rv) | +19.80±0.89[6] km/s |
| Proper motion (μ) | RA: +18.731[2] mas/yr Dec.: +8.387[2] mas/yr |
| Parallax (π) | 2.7933 ± 0.2052 mas[2] |
| Distance | 1,170 ± 90 ly (360 ± 30 pc) |
| Absolute magnitude (MV) | −1.76[3] |
| Details | |
| Radius | 102+11 −10[2] R☉ |
| Luminosity | 1,940±162[2] L☉ |
| Temperature | 3,784+188 −186[2] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
47 Capricorni is a variable star located around 1,170[2] light years from the Sun in the southern constellation Capricornus,[7] near the northern border with Aquarius. It has the variable star designation of AG Capricorni and a Bayer designation of c2 Capricorni;[8] 47 Capricorni is the Flamsteed designation. This object is visible to the naked eye as a dim, red-hued point of light with an apparent visual magnitude that varies between 5.90 and 6.14. The star is receding from the Earth with a heliocentric radial velocity of +20 km/s.[6]
In 1963, Alan William James Cousins announced that 47 Capricorni is a variable star.[9] It was given its variable star designation in 1973.[10]
This is an aging red giant star with a stellar classification of M2III.[5] It is a semiregular variable star of subtype SRb with a period of 30.592 days and a maximum brightness of 5.9 magnitude.[4] With the supply of hydrogen at its core exhausted, the star has expanded to around 102[2] times the Sun's radius. It is radiating 1,940[2] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 3,784 K.[2]
References
[edit]- ^ "Hipparcos Tools Interactive Data Access". Hipparcos. ESA. Retrieved 8 December 2021.
- ^ a b c d e f g h i j k l Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b c Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ a b c Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/gcvs. 1. Bibcode:2009yCat....102025S.
- ^ a b Houk, N.; Swift, C. (1999). "Michigan catalogue of two-dimensional spectral types for the HD Stars". Michigan Spectral Survey. 5. Bibcode:1999MSS...C05....0H.
- ^ a b Famaey, B.; et al. (2009). "Spectroscopic binaries among Hipparcos M giants,. I. Data, orbits, and intrinsic variations". Astronomy and Astrophysics. 498 (2): 627. arXiv:0901.0934. Bibcode:2009A&A...498..627F. doi:10.1051/0004-6361/200810698. S2CID 18739721.
- ^ a b "47 Cap". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2014-05-12.
- ^ Kostjuk, N. D. (2002). "HD 207005". HD-DM-GC-HR-HIP-Bayer-Flamsteed Cross Index. Institute of Astronomy of Russian Academy of Sciences; CDS. IV/27A
- ^ Cousins, A. W. J. (1963). "Photometric Data for Stars in the Equatorial Zone (Third List)". Monthly Notes of the Astron. Soc. Southern Africa. 22: 12. Bibcode:1963MNSSA..22...12C. Retrieved 8 December 2024.
- ^ Kukarkin, B. V.; Kholopov, P. N.; Kukarkina, N. P.; Perova, N. B. (October 1973). "59th Name-List of Variable Stars" (PDF). Information Bulletin on Variable Stars. 834. Bibcode:1973IBVS..834....1K. Retrieved 8 December 2024.
