QR Andromedae

QR Andromedae
Observation data; Epoch J2000 Equinox J2000
Constellation	Andromeda
Right ascension	00h 19m 49.9253s[1]
Declination	+21° 56′ 52.1666″[1]
Apparent magnitude (V)	12.16 – 13.07 variable[2]
Characteristics
Spectral type	pec(e)[2]
Apparent magnitude (B)	12.38[3]
Apparent magnitude (R)	11.86[3]
Apparent magnitude (G)	12.2395[1]
Apparent magnitude (J)	12.432[4]
Apparent magnitude (H)	12.295[4]
Apparent magnitude (K)	12.092[4]
Variable type	Algol[2]
Astrometry
Proper motion (μ)	RA: 18.469±0.071 [1] mas/yr ; Dec.: −5.529±0.079[1] mas/yr
Parallax (π)	0.4993 ± 0.0452[1] mas
Distance	6,500 ± 600 ly ; (2,000 ± 200 pc)
Orbit
Period (P)	0.6604 days[3]
Semi-amplitude (K1); (primary)	61.8±4.4[5] km/s
Other designations
	2MASS J00194992+2156521, AAVSO 0014+21
Database references
SIMBAD	data

QR Andromedae (often abbreviated to QR And) is an eclipsing binary star in the constellation Andromeda. Its maximum apparent visual magnitude is 12.16, but its light curve shows clearly eclipsing events where its brightness can drop to a magnitude of 13.07.[5] This leads to its classification as an Algol variable star.[2]

Spectrum

The optical spectrum of QR Andromedae is not of a typical stellar blackbody, but is peculiar with many emission lines,[2] the strongest being the He_II line. Balmer series and O_VI lines are also present. It was also one of the super soft X-ray sources discovered by ROSAT satellite, one of the few source of this kind observed so far in the Milky Way.[5]

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.[5]

Variability

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 arise.[5]

References

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.
N. N. Samus; O. V. Durlevich; et al. "QR And database entry". Combined General Catalog of Variable Stars (2017 ed.). CDS. Retrieved 2018-11-12.
Norton, A. J.; Wheatley, P. J.; West, R. G.; Haswell, C. A.; Street, R. A.; Collier Cameron, A.; Christian, D. J.; Clarkson, W. I.; Enoch, B.; Gallaway, M.; Hellier, C.; Horne, K.; Irwin, J.; Kane, S. R.; Lister, T. A.; Nicholas, J. P.; Parley, N.; Pollacco, D.; Ryans, R.; Skillen, I.; Wilson, D. M. (2007). "New periodic variable stars coincident with ROSAT sources discovered using SuperWASP". Astronomy and Astrophysics. 467 (2): 785. arXiv:astro-ph/0702631. Bibcode:2007A&A...467..785N. doi:10.1051/0004-6361:20077084. S2CID 16358048.
Cutri, R. M.; Skrutskie, M. F.; Van Dyk, S.; et al. (June 2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". CDS/ADC Collection of Electronic Catalogues (2246): II/246. Bibcode:2003yCat.2246....0C.
McGrath, T. K.; Schmidtke, P. C.; Cowley, A. P.; Ponder, A. L.; Wagner, R. M. (2001). "Simultaneous Photometry and Spectroscopy of the Supersoft X-Ray Source RX J0019.8+2156 (QR Andromedae)". The Astronomical Journal. 122 (3): 1578–1585. Bibcode:2001AJ....122.1578M. doi:10.1086/322109.

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.

[Gaia-1] 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.

[GCVS-2] N. N. Samus; O. V. Durlevich; et al. "QR And database entry". Combined General Catalog of Variable Stars (2017 ed.). CDS. Retrieved 2018-11-12.

[SuperWASP-3] Norton, A. J.; Wheatley, P. J.; West, R. G.; Haswell, C. A.; Street, R. A.; Collier Cameron, A.; Christian, D. J.; Clarkson, W. I.; Enoch, B.; Gallaway, M.; Hellier, C.; Horne, K.; Irwin, J.; Kane, S. R.; Lister, T. A.; Nicholas, J. P.; Parley, N.; Pollacco, D.; Ryans, R.; Skillen, I.; Wilson, D. M. (2007). "New periodic variable stars coincident with ROSAT sources discovered using SuperWASP". Astronomy and Astrophysics. 467 (2): 785. arXiv:astro-ph/0702631. Bibcode:2007A&A...467..785N. doi:10.1051/0004-6361:20077084. S2CID 16358048.

[2MASS_Cat-4] Cutri, R. M.; Skrutskie, M. F.; Van Dyk, S.; et al. (June 2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". CDS/ADC Collection of Electronic Catalogues (2246): II/246. Bibcode:2003yCat.2246....0C.

[McGrath2001-5] McGrath, T. K.; Schmidtke, P. C.; Cowley, A. P.; Ponder, A. L.; Wagner, R. M. (2001). "Simultaneous Photometry and Spectroscopy of the Supersoft X-Ray Source RX J0019.8+2156 (QR Andromedae)". The Astronomical Journal. 122 (3): 1578–1585. Bibcode:2001AJ....122.1578M. doi:10.1086/322109.