QR Andromedae

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QR Andromedae
QRAndLightCurve.png
The 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]
Astrometry
Proper motion (μ)RA: 18.469±0.071 [2]   mas/yr
Dec.: −5.529±0.079 [2]   mas/yr
Parallax (π)0.4993 ± 0.0452  mas [2]
Distance 6,500 ± 600  ly
(2,000 ± 200  pc)
Orbit
Period (P)0.6604 days [4]
Semi-amplitude (K1)
(primary)		61.8±4.4 [6] 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. [6] This leads to its classification as an Algol variable star. [3]

Contents

Spectrum

The optical spectrum of QR Andromedae is not of a typical stellar blackbody, but is peculiar with many emission lines, [3] 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. [6]

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]

Related Research Articles

<span class="mw-page-title-main">OU Andromedae</span> Rotationally variable star in the constellation Andromeda

OU Andromedae 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. It is also likely in its horizontal branch phase of evolution.

HD 224801, also known as CG Andromedae, is an Alpha² Canum Venaticorum variable star in the constellation Andromeda. Located approximately 188 parsecs (610 ly) away, the star varies between apparent magnitudes 6.32 and 6.42 over a period of approximately 3.74 days.

<span class="mw-page-title-main">RT Andromedae</span> Star in the constellation Andromeda

RT Andromedae is a variable star in the constellation of Andromeda. The system is estimated to be 322 light-years away.

<span class="mw-page-title-main">HP Lyrae</span> Variable star in the constellation Lyra

HP Lyrae is a variable star in the constellation Lyra, with a visual magnitude varying between 10.2 and 10.8. It is likely to be an RV Tauri variable, an unstable post-AGB star losing mass before becoming a white dwarf.

QV Andromedae is an Alpha2 Canum Venaticorum variable in the constellation Andromeda. Its maximum apparent visual magnitude is 6.6, so it can be seen by the naked eye under very favourable conditions. The brightness varies slightly following a periodic cycle of approximately 5.23 days.

<span class="mw-page-title-main">XZ Andromedae</span> Binary star in the constellation Andromeda

XZ Andromedae is a binary star in the constellation Andromeda. Its maximum apparent visual magnitude is 9.91, but drops down to 12.45 every 1.357 days. Its variability matches the behaviour of Algol variable stars.

<span class="mw-page-title-main">AB Andromedae</span> Binary star in the Andromeda constellation

AB Andromedae is a binary star in the constellation Andromeda. Paul Guthnick and Richard Prager discovered that the star is an eclipsing binary in 1927. Its maximum apparent visual magnitude is 9.49 but shows a variation in brightness down to a magnitude of 10.46 in a periodic cycle of roughly 8 hours. The observed variability is typical of W Ursae Majoris variable stars, so the two stars in this system form a contact binary.

<span class="mw-page-title-main">AC Andromedae</span> Variable star in the constellation Andromeda

AC Andromedae is a variable star in the constellation Andromeda. Its maximum apparent visual magnitude is 10.77, but can be seen fainter down to a magnitude of 11.9.

<span class="mw-page-title-main">AD Andromedae</span> Eclipsing binary star in the constellation Andromeda

AD Andromedae is an eclipsing binary in the constellation Andromeda. Its maximum apparent visual magnitude is 11.2, but it shows a decrease of 0.62 magnitudes during the main eclipse and 0.58 during the secondary one. It is classified as a Beta Lyrae variable star with a period of almost one day.

<span class="mw-page-title-main">BM Andromedae</span> Star in the constellation Andromeda

BM Andromedae is a T Tauri star in the constellation Andromeda. Its apparent visual magnitude has irregular variations between a maximum of 11.63 and a minimum of 14.02.

<span class="mw-page-title-main">BX Andromedae</span> Star in the constellation Andromeda

BX Andromedae is an eclipsing binary star in the constellation Andromeda. Its maximum apparent visual magnitude is 8.87. Within a cycle of approximately 14.6 hours, the brightness drops down to a magnitude of 9.53 during the main eclipse, and to a magnitude of 9.12 during the secondary one. It is classified as a Beta Lyrae variable.

<span class="mw-page-title-main">CC Andromedae</span> Star in the constellation Andromeda

CC Andromedae is a variable star in the constellation Andromeda. It is a pulsating star of the Delta Scuti type, with an apparent visual magnitude that varies between 9.19 and 9.46 with a periodicity of 3 hours.

<span class="mw-page-title-main">CN Andromedae</span> Star in the constellation Andromeda

CN Andromedae is an eclipsing binary star in the constellation Andromeda. Its maximum apparent visual magnitude is 9.62 and drops down to a minimum of 10.2 during the main eclipse. It is classified as a Beta Lyrae variable with a period roughly of 0.4628 days.

<span class="mw-page-title-main">DS Andromedae</span> Eclipsing binary star in the constellation Andromeda

DS Andromedae is an eclipsing binary star in the constellation Andromeda and a member of the open cluster NGC 752. Its maximum apparent visual magnitude is 10.44, but drops down to 10.93 during the main eclipse and to 10.71 during the secondary one.

<span class="mw-page-title-main">DX Andromedae</span> Star in the constellation Andromeda

DX Andromedae is a cataclysmic variable star in the constellation Andromeda. It has a typical apparent visual magnitude of 15.5 during the quiescent phase, but becomes brighter during outbursts recurring with a mean cycle length of 330 days, thus is classified as a dwarf nova of the SS Cygni type.

<span class="mw-page-title-main">EU Andromedae</span> Star in the constellation Andromeda

EU Andromedae is a carbon star in the constellation Andromeda. Its apparent visual magnitude varies in an irregular manner between 10.7 and 11.8.

<span class="mw-page-title-main">FF Andromedae</span> Star in the constellation Andromeda

FF Andromedae is a spectroscopic binary in the constellation Andromeda. It has a typical apparent visual magnitude of 10.4, but undergoes flare events that can increase its brightness by about a magnitude.

<span class="mw-page-title-main">HN Andromedae</span> Star in the constellation Andromeda

HN Andromedae is a variable star in the constellation Andromeda. Its apparent visual magnitude varies between 6.67 and 6.76 in a cycle of 69.51 days. It is classified as an α2 Canum Venaticorum variable.

<span class="mw-page-title-main">PX Andromedae</span> Star in the constellation Andromeda

PX Andromedae is an eclipsing cataclysmic variable star in the constellation Andromeda. It has been classified as a SW Sextantis variable, and its apparent visual magnitude varies between 14.04 and 17.

<span class="mw-page-title-main">QX Andromedae</span> Eclipsing binary star system in the constellation Andromeda

QX Andromedae is an eclipsing binary in the constellation Andromeda. It varies from a maximum apparent visual magnitude of 11.28 to a minimum of 11.50. Since it is impossible to specify the onset time of the eclipses, it is classified as a W Ursae Majoris variable star. It is also observed as an X-ray source and is a member of the open cluster NGC 752.

References

  1. ↑ Matsumoto, Katsura (1 December 1996). "BVRI Photometric Light Curves of the Galactic Supersoft X-Ray Source RX J0019.8+2156". Publications of the Astronomical Society of Japan. 48 (6): 827–831. doi:10.1093/pasj/48.6.827 . Retrieved 5 October 2021.
  2. 1 2 3 4 5 6 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. 1 2 3 4 5 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.
  4. 1 2 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.
  5. 1 2 3 Cutri, Roc M.; Skrutskie, Michael F.; Van Dyk, Schuyler D.; Beichman, Charles A.; Carpenter, John M.; Chester, Thomas; Cambresy, Laurent; Evans, Tracey E.; Fowler, John W.; Gizis, John E.; Howard, Elizabeth V.; Huchra, John P.; Jarrett, Thomas H.; Kopan, Eugene L.; Kirkpatrick, J. Davy; Light, Robert M.; Marsh, Kenneth A.; McCallon, Howard L.; Schneider, Stephen E.; Stiening, Rae; Sykes, Matthew J.; Weinberg, Martin D.; Wheaton, William A.; Wheelock, Sherry L.; Zacarias, N. (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.
  6. 1 2 3 4 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 .
  7. ↑ Greiner, J.; Wenzel, W. (February 1995). "Optical variability of the supersoft source RXJ0019.8+2156". Astronomy and Astrophysics. 294: L5–L8. arXiv: astro-ph/9411113 . Bibcode:1995A&A...294L...5G . Retrieved 9 February 2023.
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