HU Aquarii

HU Aquarii

The visual band light curve of HU Aquarii, adapted from Shengbang et al. (2016)[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Aquarius
Right ascension 21h 07m 58.19445s[2]
Declination −05° 17′ 40.5577″[2]
Apparent magnitude (V) +15.3
Characteristics
Spectral type DAm / M4.5V
Variable type AM Herculis
Astrometry
Proper motion (μ) RA: -64.579[2] mas/yr
Dec.: -62.732[2] mas/yr
Parallax (π)5.2354 ± 0.0457 mas[2]
Distance623 ± 5 ly
(191 ± 2 pc)
Details
Mass0.88/0.2 M☉
Radius0.01/0.22 R☉
Luminosity0.0022/0.0052 L☉
Temperature12,500/3,400 K
Orbit
Period (P)2.08 hours[3]
Semi-major axis (a)0.0032 au
Eccentricity (e)0.0
Inclination (i)85°
Other designations
HU Aqr, RBS 1724, RE J210755-051621, 1RXS J210758.5-051744, 1AXG J210759-0518, 2RE J210755-051630, RE J2107-051, EUVE J2108-05.2, 2RE J2107-051, RX J2107.9-0518, AAVSO 2102-05, GSC 05200-00849, RE J2107-05, RX J2107.9-0517, 2MASS J21075818-0517404, Gaia DR2 6911950900211768704[4]
Database references
SIMBADdata

HU Aquarii (abbreviated HU Aqr) is an eclipsing binary system approximately 620 light-years away from the Sun,[2] forming a cataclysmic variable of AM Herculis-type. The two stars orbit each other every 2.08 hours[3] and the ultra-short binary system includes an eclipsing white dwarf and red dwarf.

  1. ^ Cite error: The named reference Shengbang was invoked but never defined (see the help page).
  2. ^ a b c d e f 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 Howell; et al. (2002). "An Exploration of the Paradigm for the 2-3 Hour Period Gap in Cataclysmic Variables". The Astrophysical Journal. 550 (2): 897–918. arXiv:astro-ph/0005435. Bibcode:2002MNRAS.336.1129B. doi:10.1046/j.1365-8711.2002.05841.x. S2CID 609324.
  4. ^ V* HU Aqr -- CV of AM Her type (polar)