NY Virginis

NY Virginis

A light curve for NY Virginis, plotted from TESS data[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Virgo
Right ascension 13h 38m 48.14669s[2]
Declination −02° 01′ 49.2073″[2]
Apparent magnitude (V) 13.30 - 14.22[3]
Characteristics
Spectral type sdB + M5[4]
Variable type EA + RPHS[3]
Astrometry
Radial velocity (Rv)−25.0[5] km/s
Proper motion (μ) RA: −6.145±0.054 mas/yr[2]
Dec.: −12.054±0.025 mas/yr[2]
Parallax (π)1.6801 ± 0.0376 mas[2]
Distance1,940 ± 40 ly
(600 ± 10 pc)
Absolute magnitude (MV)4.49[6]
Orbit[7]
PrimaryNY Virginis A
CompanionNY Virginis B
Period (P)0.101015968166 d
Semi-major axis (a)0.0160 AU
Eccentricity (e)0.46
Details[8]
NY Virginis A
Mass0.471±0.006 M☉
Radius0.1474±0.0009 R☉
Luminosity23.3±1.5[6] L☉
Surface gravity (log g)5.76 cgs
Temperature32,850±175 K
Rotation2.42438 hours[6]
NY Virginis B
Mass0.13 M☉
Radius0.155 R☉
Surface gravity (log g)5.16 cgs
Temperature3,000[9] K
Other designations
Gaia DR2 3637481302758519040, GSC 04966-00491, 2MASS J13384814-0201491, PG 1336−018[5]
Database references
SIMBADdata

NY Virginis is a binary star about 1,940 light-years away. The primary belongs to the rare class of subdwarf B stars, being former red giants with their hydrogen envelope completely stripped by a stellar companion. The companion is a red dwarf star.[9] The binary nature of NY Virginis was first identified in 1998,[10] and the extremely short orbital period of 0.101016 d, together with brightness variability on the timescale of 200 seconds was noticed, resulting in the identification of the primary star as a B-type subdwarf in 2003.[11] Under a proposed classification scheme for hot subdwarfs it would be class sdB1VII:He1. This non-standard system indicates that it is a "normal" luminosity for a hot subdwarf and that the spectrum is dominated by hydrogen rather than helium.[12]

  1. ^ Cite error: The named reference MAST was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  3. ^ a b 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: B/gcvs. Bibcode:2009yCat....102025S.
  4. ^ Cite error: The named reference Shuo2019 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference charpinet2008 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Lee2014 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Esmer2023 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Vuckovic2007 was invoked but never defined (see the help page).
  10. ^ Kilkenny, D.; O'Donoghue, D.; Koen, C.; Lynas-Gray, A. E.; Van Wyk, F. (1998). "The EC 14026 stars - VIII. PG 1336-018: A pulsating SDB star in an HWVir-type eclipsing binary". Monthly Notices of the Royal Astronomical Society. 296 (2): 329. Bibcode:1998MNRAS.296..329K. doi:10.1046/j.1365-8711.1998.01432.x.
  11. ^ Kilkenny, D.; Reed, M. D.; O'Donoghue, D.; Kawaler, S. D.; Mukadam, A.; Kleinman, S. J.; Nitta, A.; Metcalfe, T. S.; Provencal, J. L.; Watson, T. K.; Sullivan, D. J.; Sullivan, T.; Shobbrook, R.; Jiang, X. J.; Joshi, S.; Ashoka, B. N.; Seetha, S.; Leibowitz, E.; Ibbetson, P.; Mendelson, H.; Meištas, E.; Kalytis, R.; Ališauskas, D.; Martinez, P.; Van Wyk, F.; Stobie, R. S.; Marang, F.; Zola, S.; Krzesinski, J.; et al. (2003). "A Whole Earth Telescope campaign on the pulsating subdwarf B binary system PG 1336-018 (NY Vir)". Monthly Notices of the Royal Astronomical Society. 345 (3): 834. Bibcode:2003MNRAS.345..834K. doi:10.1046/j.1365-8711.2003.07007.x. hdl:10183/89981.
  12. ^ Drilling, J. S.; Jeffery, C. S.; Heber, U.; Moehler, S.; Napiwotzki, R. (2013). "An MK-like system of spectral classification for hot subdwarfs". Astronomy & Astrophysics. 551: A31. Bibcode:2013A&A...551A..31D. doi:10.1051/0004-6361/201219433.