S Normae

S Normae
Location of S Normae (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Norma
Right ascension 16h 18m 51.8325s[1]
Declination −57° 53′ 59.244″[1]
Apparent magnitude (V) 6.394[2] (6.12 - 6.77[3])
Characteristics
Spectral type F8-G0Ib[3] + B9.5V[4]
U−B color index +0.66[5]
B−V color index +1.00[5]
Variable type δ Cepheid[3]
Astrometry
Radial velocity (Rv)5.83[6] km/s
Proper motion (μ) RA: 0.07[1] mas/yr
Dec.: 0.04[1] mas/yr
Parallax (π)1.16 ± 0.76 mas[1]
Distance924[2] pc
Absolute magnitude (MV)-4.02[4]
Orbit[4]
Period (P)8,660 yr
Semi-major axis (a)794 AU
Details[4]
Mass6.3 M☉
Radius65.6[2] R☉
Luminosity3,630 L☉
Temperature6,350 K
Metallicity+0.10[7]
companion
Mass2.4 M☉
Age80[8] Myr
Other designations
S Nor, HR 6062, SAO 243586, CD−57°6342, GSC 08719-00158, HD 146323, NGC 6087 132, GC 21898, HIP 79932, NGC 6087 155
Database references
SIMBADdata
S Normae is the brightest member of the open cluster NGC 6087.

S Normae (S Nor) is a yellow supergiant variable star in the constellation Norma. It is the brightest member of the open cluster NGC 6087.

S Normae is a Classical Cepheid variable with a visual magnitude range of 6.12 to 6.77 and a period of 9.75411 days. The spectral type varies during the pulsation cycle from F8 to G0. Its mass has been measured at 6.3 M☉ with reference to a close orbital companion, and it is over 3,000 times as luminous as the sun.

  1. ^ a b c d e 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. ^ a b c Moskalik, P.; Gorynya, N. A. (2005). "Mean Angular Diameters and Angular Diameter Amplitudes of Bright Cepheids". Acta Astronomica. 55: 247. arXiv:astro-ph/0507076. Bibcode:2005AcA....55..247M.
  3. ^ 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. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
  4. ^ a b c d Cite error: The named reference evans13 was invoked but never defined (see the help page).
  5. ^ a b Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
  6. ^ Mermilliod, J. C.; Mayor, M.; Udry, S. (2008). "Red giants in open clusters. XIV. Mean radial velocities for 1309 stars and 166 open clusters". Astronomy and Astrophysics. 485 (1): 303–314. Bibcode:2008A&A...485..303M. CiteSeerX 10.1.1.30.7545. doi:10.1051/0004-6361:200809664.
  7. ^ Klagyivik, P.; Szabados, L. (2009). "Observational studies of Cepheid amplitudes. I. Period-amplitude relationships for Galactic Cepheids and interrelation of amplitudes". Astronomy and Astrophysics. 504 (3): 959. arXiv:0908.3561. Bibcode:2009A&A...504..959K. doi:10.1051/0004-6361/200811464. S2CID 18283579.
  8. ^ Netopil, M.; Paunzen, E.; Heiter, U.; Soubiran, C. (2016). "On the metallicity of open clusters. III. Homogenised sample". Astronomy & Astrophysics. 585: A150. arXiv:1511.08884. Bibcode:2016A&A...585A.150N. doi:10.1051/0004-6361/201526370. S2CID 118382876.