AR Andromedae

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AR Andromedae
ARAndLightCurve.png
A visual band light curve for AR Andromedae, from AAVSO data, showing five outbursts. [1]
Observation data
Epoch J2000       Equinox J2000
Constellation Andromeda
Right ascension 01h 45m 03.27155s [2]
Declination +37° 58′ 33.2379″ [2]
Apparent magnitude  (V)11.0 –17.6 variable [3]
Characteristics
Spectral type pec(UG) [3]
Apparent magnitude  (B)12.8
Apparent magnitude  (V)11.00 [4]
Apparent magnitude  (G)16.3185 [2]
Apparent magnitude  (J)14.589 [5]
Apparent magnitude  (H)13.996 [5]
Apparent magnitude  (K)13.730 [5]
Variable type UGSS [3]
Astrometry
Proper motion (μ)RA: 5.431±0.046 [2]   mas/yr
Dec.: −7.249±0.059 [2]   mas/yr
Parallax (π)2.4070 ± 0.0666  mas [2]
Distance 1,360 ± 40  ly
(420 ± 10  pc)
Orbit [6]
Period (P)0.16302±0.00032 days
Periastron epoch (T)HJD 2450005.6924±0.0021
Semi-amplitude (K1)
(primary)		91±7 km/s
Other designations
2MASS J01450327+3756334, CRTS J014503.3+375633 [7]
Database references
SIMBAD data

AR Andromedae (AR And) is a dwarf nova of the SS Cygni type in the constellation Andromeda. Its typical apparent visual magnitude is 17.6, but increases up to 11.0 magnitude during outbursts. The outbursts occur approximately every 23 days. [3]

Contents

System

Dwarf novae systems are made up by a classical star with a white dwarf companion. By measuring the Doppler shift of spectral lines, it was found to have an orbital period of 3.91 hours. [6] The accretion disk around white dwarf seems to be axisymmetric and devoid of structure. [8]

Variability

AR Andromedae was first listed as a variable star by Frank Elmore Ross in 1929, based on observations in 1907 (when the star was too faint to detect) and 1927 (when the star had flared to magnitude 12). [9] It was initially classified as a Mira variable star. [10] In 1934 it was given the variable star designation AR Andromedae. [11]

The light emitted by dwarf novae like AR Andromedae comes entirely from the accretion disc and the white dwarf; the luminosity increase during outbursts is typically induced by a variation in the accretion rate of the white dwarf. The outbursts are unusually frequent, with 19 outbursts detected by 2016. [12]

Spectrum

The spectral type of AR Andromedae is classified as peculiar of the U Geminorum type, [3] since the spectrum is not a typical stellar blackbody. It also shows strong emission lines of the first two Balmer series lines as well as HeI ones. In addition, an unusually strong FeII line with other possible weak lines of the same origin were also reported. [6]

Related Research Articles

<span class="mw-page-title-main">U Geminorum</span> Star in the constellation Gemini

U Geminorum, in the constellation Gemini, is an archetypal example of a dwarf nova. The binary star system consists of a white dwarf closely orbiting a red dwarf. Every few months it undergoes an outburst that greatly increases its brightness. The dwarf nova class of variable stars are often referred to as U Geminorum variables after this star.

<span class="mw-page-title-main">WZ Sagittae</span> Variable star in the constellation Sagitta

WZ Sagittae is a cataclysmic dwarf nova star system in the constellation Sagitta. It consists of a white dwarf primary being orbited by a low mass companion. The white dwarf is about 0.85 solar masses while the companion is only 0.08 solar masses. This implies that the companion is a spectral class L2 star, although this has yet to be confirmed. The distance to this system has been determined by parallax, yielding a distance of 45.1 parsecs.

<span class="mw-page-title-main">RX Andromedae</span> Cataclysmic variable star system in the constellation Andromeda

RX Andromedae is a variable star in the constellation of Andromeda. Although it is classified as a dwarf nova of the Z Camelopardalis (UGZ) type, it has shown low-luminosity periods typical of VY Sculptoris stars. However, for most of the time it varies from an apparent visual magnitude of 15.1 at minimum brightness to a magnitude of 10.2 at maximum brightness, with a period of approximately 13 days.

<span class="mw-page-title-main">SS Cygni</span> Variable star in the constellation Cygnus

SS Cygni is a variable star in the northern constellation Cygnus. It is the prototype of the subclass of dwarf novae that show only normal eruptions. It typically rises from 12th magnitude to 8th magnitude for 1–2 days every 7 or 8 weeks. The northerly declination of SS Cygni makes the star almost circumpolar from European and North American latitudes, allowing a large proportion of the world's amateur astronomers to monitor its behavior. Furthermore, since the star lies against the rich backdrop of the Milky Way band, the telescope field of view around SS Cygni contains an abundance of useful brightness comparison stars.

<span class="mw-page-title-main">RZ Gruis</span> Star in the constellation of Grus

RZ Gruis is a nova-like binary system in the constellation Grus composed of a white dwarf and an F-type main-sequence star. It is generally of apparent magnitude of 12.3 with occasional dimming to 13.4. Its components are thought to orbit each other roughly every 8.5 to 10 hours. It belongs to the UX Ursae Majoris subgroup of cataclysmic variable star systems, where material from the donor star is drawn to the white dwarf where it forms an accretion disc that remains bright and outshines the two component stars. The system is around 1,434 light-years away from Earth; or as much as 1,770 light years based on a Gaia parallax.

<span class="mw-page-title-main">Q Cygni</span> 1876 Nova in the constellation Cygnus

Q Cygni, is a star located in the constellation Cygnus. It is also known as Nova Cygni 1876, and has the designation NGC 7114, and HR 8296. Nova Cygni is located in the northwestern portion of Cygnus along the border with Lacerta.

<span class="mw-page-title-main">SU Ursae Majoris</span> Variable star in the constellation Ursa Major

SU Ursae Majoris, or SU UMa, is a close binary star in the northern circumpolar constellation of Ursa Major. It is a periodic cataclysmic variable that varies in magnitude from a peak of 10.8 down to a base of 14.96. The distance to this system, as determined from its annual parallax shift of 4.53 mas, is 719 light-years. It is moving further from the Earth with a heliocentric radial velocity of +27 km/s.

<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">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">EG Andromedae</span> Binary star system in the constellation Andromeda

EG Andromedae is a symbiotic binary in the constellation Andromeda. Its apparent visual magnitude varies between 6.97 and 7.80.

<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">LL Andromedae</span> Dwarf nova star in the constellation Andromeda

LL Andromedae is a dwarf nova in the constellation Andromeda, discovered during an outburst in 1979. Its typical apparent visual magnitude is 19.4, but undergoes outbursts events when can reach a peak magnitude of 14.3. Since this magnitude is reached during the most powerful outbursts, while less bright outbursts can occur, it is classified as a SU Ursae Majoris 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">QR Andromedae</span> Eclipsing binary star in the constellation Andromeda

QR Andromedae 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. This leads to its classification as an Algol variable star.

<span class="mw-page-title-main">V455 Andromedae</span> Dwarf nova star in the constellation Andromeda

V455 Andromedae is a dwarf nova in the constellation Andromeda. It has a typical apparent visual magnitude of 16.5, but reached a magnitude of 8.5 during the only observed outburst.

<span class="mw-page-title-main">V705 Cassiopeiae</span> Nova seen in 1993

V705 Cassiopeiae, also known as Nova Cassiopeiae 1993 was a nova which erupted in the constellation Cassiopeia during 1993. The nova was discovered at 11:17 UT on 7 December 1993 by amateur astronomer Kazuyoshi Kanatsu of Matsue, Japan, who photographed it using a 35mm camera with a 55mm f/2.8 lens. Asteroid 6976 Kanatsu was named after him in honor of this discovery. At the time of its discovery the nova had a photographic magnitude of 6.5. Around 18 December 1993 it flared briefly to magnitude 5.3, and then it returned rapidly to magnitude 6.5. It underwent a series of smaller flares until mid February 1993, after which it began a precipitous decline in brightness.

<span class="mw-page-title-main">BZ Ursae Majoris</span> Dwarf Nova in the constellation Ursa Major

BZ Ursae Majoris is a dwarf nova star system in the northern circumpolar constellation of Ursa Major. It consists of a white dwarf primary in a close orbit with a red dwarf. The latter star is donating mass, which is accumulating in an accretion disk orbiting the white dwarf. The system is located at a distance of approximately 505 light years from the Sun based on parallax measurements.

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

IW Andromedae is a binary star system in the northern constellation of Andromeda, abbreviated IW And. It is the prototype of a class of variable stars known as IW And variables, which is an anomalous sub-class of the Z Camelopardalis variables. The brightness of this system ranges from an apparent visual magnitude of 13.7 down to 17.3, which requires a telescope to view. The system is located at a distance of approximately 2,860 light years from the Sun based on parallax measurements.

References

  1. ↑ "Download Data". aavso.org. AAVSO. Retrieved 1 October 2021.
  2. 1 2 3 4 5 6 Vallenari, A.; et al. (Gaia Collaboration) (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics . arXiv: 2208.00211 . doi: 10.1051/0004-6361/202243940 . Gaia DR3 record for this source at VizieR.
  3. 1 2 3 4 5 AR And, database entry, Combined General Catalog of Variable Stars (GCVS4.2, 2004 Ed.), N. N. Samus, O. V. Durlevich, et al., CDS ID II/250 Accessed on line 2018-10-24.
  4. ↑ Database entry, Catalogue of Stellar Photometry in Johnson's 11-color system (2002 Ed.), J. R. Ducati, CDS ID Accessed on line 2018-10-24.
  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 Taylor, C. J.; Thorstensen, J. R. (October 1996). "Orbital Periods of the Dwarf Novae AR And, AM Cas, and PY Per". Publications of the Astronomical Society of the Pacific. 108: 894. Bibcode:1996PASP..108..894T. doi: 10.1086/133810 .
  7. ↑ "AR And". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved October 24, 2018.
  8. ↑ Ruiz-Carmona, R.; Groot, P. J.; Steeghs, D. (2019), "A systematic study of spiral density waves in the accretion discs of cataclysmic variables", Monthly Notices of the Royal Astronomical Society, 491 (2): 2217–2253, arXiv: 1910.12089 , doi:10.1093/mnras/stz2992
  9. ↑ Ross, F. E. (August 1929). "New variable stars (eight list) - New proper-motion stars. (seventh list)". Astronomical Journal. 39: 140–142. Bibcode:1929AJ.....39..140R. doi:10.1086/104923 . Retrieved 12 March 2023.
  10. ↑ Morgenroth, O. (December 1933). "62 neue Veränderlilche". Astronomische Nachrichten. 250 (5): 75. Bibcode:1933AN....250...75M. doi:10.1002/asna.19332500503 . Retrieved 12 March 2023.
  11. ↑ Guthnick, P.; Prager, R. (April 1934). "Benennung von veränderlichen Sternen". Astronomische Nachrichten. 251 (17): 257. Bibcode:1934AN....251..257G. doi:10.1002/asna.19342511702 . Retrieved 12 March 2023.
  12. ↑ Statistical properties of dwarf novae-type cataclysmic variables: the outburst catalogue supplementary data
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