S Pegasi

S Pegasi (S Peg) is a Mira variable star in the constellation Pegasus. It varies between magnitude 7 and 13 with a period of 319.22 days.[2] It is believed to be pulsating in the first overtone. First overtone pulsators have masses less than 1.8 M_☉ at a temperature of 2,107 K, and less than 1.4 M_☉ at the luminosity of S Pegasi.[4]

S Pegasi

Observation data Epoch J2000      Equinox J2000
Constellation	Pegasus
Right ascension	23^h 20^m 32.61407^s[1]
Declination	+08° 55′ 08.1398″[1]
Apparent magnitude (V)	6.9 - 13.8[2]
Characteristics
Spectral type	M5e - M8.5e[2]
Variable type	Mira[2]
Astrometry
Parallax (π)	2.52 ± 2.26[1] mas
Distance	approx. 1,000 ly (approx. 400 pc)
Details
Radius	459 - 574[3] R☉
Luminosity	3,221[4] L☉
Temperature	2,107[4] K
Other designations
S Peg, BD+08° 5047a, HD 220033, HIP 115242
Database references
SIMBAD	data

References

1. Van Leeuwen, F. (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. S2CID 18759600.
2. 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. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
3. Van Belle, G. T.; Thompson, R. R.; Creech-Eakman, M. J. (2002). "Angular Size Measurements of Mira Variable Stars at 2.2 Microns. II". The Astronomical Journal. 124 (3): 1706–1715. arXiv:astro-ph/0210167. Bibcode:2002AJ....124.1706V. doi:10.1086/342282. S2CID 33832649.
4. Serkowski, Krzysztof; Shawl, Stephen J. (2001). "Polarimetry of 167 Cool Variable Stars: Data". The Astronomical Journal. 122 (4): 2017. Bibcode:2001AJ....122.2017S. doi:10.1086/323105.