QR Andromedae
visual band light curve of QR Andromedae (adapted from Matsumoto (1996)), The phase is with respect to the 15.85 hour orbital period.[1] | ||
Observation data Epoch J2000 Equinox J2000 | ||
---|---|---|
Constellation | Andromeda | |
Right ascension | 00h 19m 49.9253s[2] | |
Declination | +21° 56′ 52.1666″[2] | |
Apparent magnitude (V) | 12.16 – 13.07 variable[3] | |
Characteristics | ||
Spectral type | pec(e)[3] | |
Apparent magnitude (B) | 12.38[4] | |
Apparent magnitude (R) | 11.86[4] | |
Apparent magnitude (G) | 12.2395[2] | |
Apparent magnitude (J) | 12.432[5] | |
Apparent magnitude (H) | 12.295[5] | |
Apparent magnitude (K) | 12.092[5] | |
Variable type | Algol[3] | |
Semi-amplitude (K1) (primary) 61.8±4.4[6] km/s | | |
AAVSO 0014+21 | ||
Database references | ||
SIMBAD | data |
QR Andromedae (often abbreviated to QR And) is an
Spectrum
The optical spectrum of QR Andromedae is not of a typical stellar
System
It is now commonly accepted that super soft X-ray sources are white dwarfs that are burning matter with nuclear fusion on their surfaces, sustained by a high accretion rate of matter coming from a companion star. QR Andromedae is the nearest and brightest of those sources, and it has an orbital period of 15.85 hours. The companion star has a mass between 0.3 – 0.5 M☉ and should be a remnant of a more massive evolved star that is filling its Roche lobe.[6]
Variability
Photographic plates from the Harvard College and Sonneberg observatories have recorded QR Andromedae's brightness history since the late 19th century. Jochen Greiner and Wolfgang Wenzel constructed a 100 year light curve for the star. They found that the light curve exhibited brightness changes of up to one magnitude, on a variety of timescales. They proposed that this was the result of unstable mass transfers onto the white dwarf, triggering sporadic hydrogen burning.[7]
Eclipses in the light curve of QR Andromedae are not symmetrical: the ingress is more gradual than the egress. The secondary minimum is variable in occurring phase and depth, meaning that the occultation of the secondary star happens behind a variable part of the disk. Out of the eclipses, light flickering can be clearly seen, and in some observations a periodicity arises.[6]
References
- . Retrieved 5 October 2021.
- ^ .
- ^ CDS. Retrieved 2018-11-12.
- ^ S2CID 16358048.
- ^ Bibcode:2003yCat.2246....0C.
- ^ doi:10.1086/322109.
- Bibcode:1995A&A...294L...5G. Retrieved 9 February 2023.