DQ Herculis

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Star
DQ Herculis
AladinLite
Observation
dates equinox :  J2000.0 , epoch : J2000.0
Constellation Hercules
Right ascension 18 h 07 m 30.25 s
declination + 45 ° 51 ′ 32.6 ″
Apparent brightness (15,16) mag
Typing
B − V color index (−2.17) 
Spectral class WD / M3 Ve
Variable star type Yes 
Astrometry
parallax (2.00 ± 0.02)  mas
distance (1630 ± 15)  ly
(500)  pc
Proper movement 
Rec. Share: (−0.95 ± 0.05)  mas / a
Dec. portion: (12.4 ± 0.04)  mas / a
Physical Properties
Dimensions 0.6 / 0.4  M ☉
Other names
and catalog entries
2MASS catalog 2MASS J18073024 + 4551325 [1]
Other names DQ Herculis, Nova Herculis 1934

DQ Herculis (also Nova Herculis 1934 ) is a binary star system consisting of a red dwarf and a white dwarf in the constellation Hercules with a distance of about 1600  light years . It forms the prototype of the so-called DQ Herculis stars , which belong to the cataclysmic variables . The entire system has roughly the same mass as the sun, with the greater part of around 0.6 solar masses falling on the white dwarf and the smaller part of just under 0.4 solar masses falling on the red dwarf.

history

DQ Herculis was discovered as a slow nova in December 1934, and reached a maximum brightness of 1.5 mag . The nova remnant is a bright cataclysmic variable (CV) with a free rotating, magnetic white dwarf. The white dwarf in DQ Herculis rotates with a period of 142 seconds and is one of the fastest rotating white dwarfs at all. Due to the high inclination of almost 90 °, it comes in the course of a railway circulation of 4.65 hours a covering of the white dwarf and the accretion disk by the companion star.

Web links

Individual evidence

  1. ↑ a b c d e DQ Her. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed September 16, 2018 .
  2. ↑ DQ Her. In: VSX. AAVSO, accessed September 16, 2018 .
  3. ↑ a b Horne, K., Welsh, W., Wade, R .: On the mass of nova DQ Hercules (1934) . In: Astrophysical Journal . 410, No. 1, 06/1993, pp. 357-364. bibcode : 1993ApJ ... 410..357H .
  4. ^ A b Zhang E., Robinson EL, Stiening RF, Horne K .: The 71 Second Oscillation in the Light Curve of the Old Nova DQ Herculis . In: The Astrophysical Journal . 454, 1995, p. 447. bibcode : 1995ApJ ... 454..447Z . doi : 10.1086 / 176496 .