OU Andromedae

OU Andromedae

The light curve of an X-ray flare observed in 2001 by the Chandra X-ray Observatory is shown. This flare is believed to have been produced by a coronal mass ejection. (Adapted from Argiroffi et al., 2019[1])
Observation data
Epoch J2000      Equinox J2000
Constellation Andromeda
Right ascension 23h 49m 40.9598s[2]
Declination +36° 25′ 31.0082″[2]
Apparent magnitude (V) 5.87 - 5.94[3]
Characteristics
Spectral type G1 IIIe[4]
Apparent magnitude (G) 5.6187[2]
Apparent magnitude (J) 4.723[5]
Apparent magnitude (H) 4.208[5]
Apparent magnitude (K) 4.097[5]
B−V color index 0.79[4]
Variable type FK Com[3]
Astrometry
Radial velocity (Rv)−1.89±0.25[2] km/s
Proper motion (μ) RA: −0.858±0.094[2] mas/yr
Dec.: −47.402±0.078[2] mas/yr
Parallax (π)7.1692 ± 0.0677 mas[2]
Distance455 ± 4 ly
(139 ± 1 pc)
Details[6]
Mass2.85 M☉
Radius9.46 R☉
Luminosity71.2 L☉
Surface gravity (log g)2.8 cgs
Temperature5,360 K
Metallicity [Fe/H]−0.07 dex
Rotation24.3 days
Rotational velocity (v sin i)21.5 km/s
Age645 – 891[7] Myr
Other designations
2MASS J23494097+3625309, FK5 3914, HIP 117503, SAO 73535, BD+35°5110, HR 9024, HD 223460, PPM 89159
Database references
SIMBADdata

OU Andromedae (also HR 9024) is a rotationally variable star in the constellation Andromeda. Varying between magnitudes 5.87 and 5.94, it has been classified as an FK Comae Berenices variable, but the classification is still uncertain. It has a spectral classification of G1IIIe, meaning that it is a giant star that shows emission lines in its spectrum.[3] It is also likely in its horizontal branch phase of evolution.[7]

In 1985, Jeffrey Hopkins et al. discovered that HR 9024 is a variable star, with a period of ~23.3 days.[8] It was given the variable star designation OU Andromedae in 1986.[9] Paola Testa et al. reported that the star showed X-ray flare activity, in 2007.[10]

  1. ^ Cite error: The named reference natast was invoked but never defined (see the help page).
  2. ^ a b c d e f g 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.
  3. ^ a b c Cite error: The named reference gcvs was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Silva2015 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference 2MASS Cat was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Borisova2016 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Stock2018 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Hopkins1985 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Kholopov1987 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Testa2007 was invoked but never defined (see the help page).