Fomalhaut

Fomalhaut (Alpha Piscis Austrini, Alpha PsA, α Piscis Austrini, α PsA) is the brichtest starn in the constellation Piscis Austrinus an ane o the brichtest starns in the sky.

Fomalhaut

DSS image o Fomalhaut, field o view 2.7×2.9 degrees. Credit NASA, ESA, an the Deegitised Sky Survey 2. Acknowledgment: Davide De Martin (ESA/Hubble)
Observation data Epoch J2000      Equinox J2000
Constellation	Piscis Austrinus (Fomalhaut A+B), Aquarius (Fomalhaut C)
Fomalhaut
Richt ascension	22h 57m 39.0465s[1]
Declination	−29° 37′ 20.050″[1]
Apparent magnitude (V)	1.16
TW Piscis Austrini
Richt ascension	22h 56m 24.05327s[1]
Declination	−31° 33′ 56.0351″[1]
Apparent magnitude (V)	6.48[2]
LP 876-10
Richt ascension	22h 48m 04.47s[3]
Declination	−24° 22′ 07.5″[3]
Apparent magnitude (V)	12.618[3]
Chairactereestics
Spectral type	A3 V / K5Vp / M4V[3][4]
U−B colour index	0.08 / 1.02 / ?[5]
B−V colour index	0.09 / 1.10 / 1.683[3][5]
Variable teep	None / BY Draconis / ?
Astrometry
Fomalhaut
Radial velocity (Rv)	+6.5 km/s
Proper motion (μ)	RA: +328.95[1] mas/yr Dec.: −164.67[1] mas/yr
Parallax (π)	129.81 ± 0.47[1] mas
Distance	25.13 ± 0.09 ly (7.70 ± 0.03 pc)
Absolute magnitude (MV)	1.72[6]
TW Piscis Austrini
Radial velocity (Rv)	+6[2] km/s
Proper motion (μ)	RA: −331.11[1] mas/yr Dec.: −158.98[1] mas/yr
Parallax (π)	131.42 ± 0.62[1] mas
Distance	24.8 ± 0.1 ly (7.61 ± 0.04 pc)
Absolute magnitude (MV)	7.08[6]
Details
Fomalhaut
Mass	7000192000000000000♠1.92±0.02[6] M☉
Radius	7000184200000000000♠1.842±0.019[6] R☉
Luminosity	7001166300000000000♠16.63±0.48[6] L☉
Surface gravity (log g)	4.21[7] cgs
Temperatur	8,590[6] K
Metallicity [Fe/H]	−0.03[8] tae −0.34[9] dex
Rotational velocity (v sin i)	93[7] km/s
Age	7008440000000000000♠(4.4±0.4)×108[6] years
TW Piscis Austrini
Mass	0.725 ± 0.036[4] M☉
Radius	0.629 ± 0.051[4] R☉
Luminosity	0.19[6] L☉
Temperatur	4,711 ± 134[4] K
Rotational velocity (v sin i)	2.93[4] km/s
Age	4.4 × 108[6] years
Ither designations
Fomalhaut: α Piscis Austrini, α PsA, Alpha PsA, 24 Piscis Austrini, CPD −30° 6685, FK5 867, Gl 881, HD 216956, HIP 113368, HR 8728, SAO 191524
TW Piscis Austrini: Fomalhaut B, TW PsA, Gl 879, HR 8721, CD -32°17321, HD 216803, LTT 9283, GCTP 5562.00, SAO 214197, CP(D)-32 6550, HIP 113283
LP 876-10: Fomalhaut C, 2MASS J22480446-2422075, NLTT 54872, GSC 06964-01226
Database references
Fomalhaut
SIMBAD	data
Exoplanet Archive	data
ARICNS	data
Extrasolar Planets Encyclopaedia	data
TW Piscis Austrini
SIMBAD	data
ARICNS	data

References

1. van Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
2. "V* TW PsA -- Variable of BY Dra type". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 20 Januar 2010.
3. "LP 876-10 -- Double or multiple star". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 30 Julie 2014.
4. Demory, B.-O.; et al. (October 2009), "Mass-radius relation of low and very low-mass stars revisited with the VLTI", Astronomy and Astrophysics, 505 (1): 205–215, arXiv:0906.0602, Bibcode:2009A&A...505..205D, doi:10.1051/0004-6361/200911976
5. Johnson, H. L.; Iriarte, B.; Mitchell, R. I.; Wisniewskj, W. Z. (1966). "UBVRIJKL photometry of the bright stars". Communications of the Lunar and Planetary Laboratory. 4 (99). Bibcode:1966CoLPL...4...99J.CS1 maint: multiple names: authors leet (link)
6. Mamajek, E.E. (August 2012). "On the Age and Binarity of Fomalhaut". Astrophysical Journal Letters. 754 (2): L20. arXiv:1206.6353. Bibcode:2012ApJL..754...20M. doi:10.1088/2041-8205/754/2/L20.
7. Di Folco, E.; Thévenin, F.; Kervella, P.; Domiciano de Souza, A.; Coudé du Foresto, V.; Ségransan, D.; Morel, P. (November 2004). "VLTI near-IR interferometric observations of Vega-like stars. Radius and age of α PsA, β Leo, β Pic, ɛ Eri and τ Cet". Astronomy and Astrophysics. 426 (2): 601–617. Bibcode:2004A&A...426..601D. doi:10.1051/0004-6361:20047189.CS1 maint: multiple names: authors leet (link) This paper lists [Fe/H] = −0.10 dex.
8. Dunkin, S. K.; Barlow, M. J.; Ryan, Sean G.; Barlow; Ryan (Apryle 1997). "High-resolution spectroscopy of Vega-like stars - I. Effective temperatures, gravities and photospheric abundances". Monthly Notices of the Royal Astronomical Society. 286 (3): 604–616. Bibcode:1997MNRAS.286..604D. doi:10.1093/mnras/286.3.604.CS1 maint: multiple names: authors leet (link) This paper lists [Fe/H] = −0.03 dex.
9. Saffe, C.; Gómez, M.; Pintado, O.; González, E. (October 2008). "Spectroscopic metallicities of Vega-like stars". Astronomy and Astrophysics. 490 (1): 297–305. arXiv:0805.3936. Bibcode:2008A&A...490..297S. doi:10.1051/0004-6361:200810260.CS1 maint: multiple names: authors leet (link) This paper lists [Fe/H] = −0.34 dex.