RX Andromedae

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RX Andromedae
RXAndLightCurve.png
The visual band light curve of RX Andromedae, from AAVSO data [1]
Observation data
Epoch J2000       Equinox J2000
Constellation Andromeda
Right ascension 01h 04m 35.53730s [2]
Declination +41° 17′ 57.78369″ [2]
Apparent magnitude  (V)10.2 to 15.1 [3]
Characteristics
Spectral type pec(UG) [3]
B−V color index -0.4556 [4]
Variable type UGZ [3]
Astrometry
Radial velocity (Rv)-12 [5]  km/s
Proper motion (μ)RA: 1.217 ± 2.221 [6]   mas/yr
Dec.: -22.225 ± 0.699 [6]   mas/yr
Parallax (π)5.0276 ± 0.0507  mas [2]
Distance 649 ± 7  ly
(199 ± 2  pc)
Orbit
Period (P)5.075 [7] hours
Details
White dwarf
Mass 0.8 [8]   M☉
Surface gravity (log g)8.2 [8]   cgs
Temperature 40,000 - 45,000 [8]   K
Rotational velocity (v sin i)200 [8]  km/s
Donor star
Surface gravity (log g)4.5 [9]   cgs
Temperature 3,500 [9]   K
Metallicity +0.07 [9]
Other designations
2MASS J01043553+4117577, TYC 2807-1623-1
Database references
SIMBAD data

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. [10] 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. [3]

Contents

System

RX Andromedae is a cataclysmic variable system, where a white dwarf with a mass of 0.8 M☉ and an M2 main sequence star [9] are rotating around their center of mass. The main sequence star is overfilling its Roche lobe, so the white dwarf is stripping away matter from the companion star and accreting it through an accretion disk. [10]

Variability

Like the Z Camelopardalis variables, RX Andromedae shows some periods of roughly constant luminosity and others where its brightness oscillates between a magnitude of 10.2 at its maximum and one of 15.1 at its minimum. However, between 1996 and 1997 it was stuck at its minimum brightness like cataclysmic variables of VY Sculptoris type, before going back to the usual behaviour. This places RX Andromedae in a transitional state between those two kind of objects. [10] The white dwarf and its accretion disk seems to be entirely responsible for this variability, and it's driven by changes in the accretion rate of the white dwarf. [8]

Spectrum

RX Andromedae has been extensively studied in optical and ultraviolet. It's also one of the few dwarf nova systems that have been detected at radio wavelengths. [11]

Related Research Articles

<span class="mw-page-title-main">Cataclysmic variable star</span> Stars with irregular large fluctuations in brightness

In astronomy, cataclysmic variable stars (CVs) are stars which irregularly increase in brightness by a large factor, then drop back down to a quiescent state. They were initially called novae, since ones with an outburst brightness visible to the naked eye and an invisible quiescent brightness appeared as new stars in the sky.

<span class="mw-page-title-main">V1494 Aquilae</span> Nova seen in 1999 in the constellation of Aquila

V1494 Aquilae or Nova Aquilae 1999 b was a nova which occurred during 1999 in the constellation Aquila and reached a brightness of magnitude 3.9 on 2 December 1999. making it easily visible to the naked eye. The nova was discovered with 14×100 binoculars by Alfredo Pereira of Cabo da Roca, Portugal at 18:50 UT on 1 December 1999, when it had a visual magnitude of 6.0.

<span class="mw-page-title-main">AM Herculis</span> Star in the constellation Hercules

AM Herculis is a binary variable star located in the constellation Hercules. This star, along with the star AN Ursae Majoris, is the prototype for a category of cataclysmic variable stars called polars, or AM Her type stars.

Z Andromedae is a binary star system consisting of a red giant and a white dwarf. It is the prototype of a type of cataclysmic variable star known as symbiotic variable stars or simply Z Andromedae variables. The brightness of those stars vary over time, showing a quiescent, more stable phase and then an active one with a more pronounced variability and stronger brightening and/or dimming.

<span class="mw-page-title-main">BB Doradus</span> Cataclysmic variable star in the constellation Dorado

BB Doradus or BB Dor is a cataclysmic variable, a pre-nova star, thus a close pair binary star system. It is composed of a red dwarf and a white dwarf. Observations of the white dwarf's faint but certain accretion disk are consistent with it being at ~10° inclination.

<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">EX Hydrae</span> Cataclysmic binary star system in the constellation Hydra

EX Hydrae is a variable star classified as an eclipsing intermediate polar-type cataclysmic variable, specifically of the DQ Herculis type. The system varies in apparent magnitude from 9.6 to 14. The system consists of a white dwarf primary and an M-type secondary, of masses of 0.4–0.7 M☉ and 0.07–0.10 M☉ respectively. The orbital period is 98.25696 minutes (0.068233846 days). The system is 65±11 parsecs distant, making EX Hya one of the closest cataclysmic variable stars. The cataclysmic outbursts appear to be caused by accretion of material from the M-star to the white dwarf.

Z Camelopardalis (Z Cam) is a cataclysmic variable star system in the northern constellation of Camelopardalis. It has an apparent visual magnitude which varies between 9.8 and 14.5. This system is the prototype star for the family of Z Camelopardalis variable stars: dwarf novae with standstills at a brightness intermediate between their maxima and minima. It may be the same bright nova that was recorded by Chinese astrologers in the autumn of 77 BCE.

<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">TU Andromedae</span> Star in the constellation Andromeda

TU Andromedae is a variable star of the Mira type in the constellation Andromeda. It has a spectral type of M5e and a visual magnitude which varies between extremes of 7.6 and 13.5.

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

AR Andromedae 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.

<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">OS Andromedae</span> Nova event seen in 1986

OS Andromedae, known also as Nova Andromedae 1986, is a classical nova that appeared in the constellation Andromeda during 1986. It was discovered at 10:34 UT on 5 December 1986 by Mitsuri Suzuki, a 28-year-old school teacher living in Ena, Japan. He photographed the portion of the Milky Way that passes through northern Andromeda with a 200-mm telephoto lens, and found the nova when its apparent magnitude was 8.0. Two days later it reached a peak apparent visual magnitude of 6.3.

<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">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">YZ Reticuli</span> 2020 Nova in the constellation Reticulum

YZ Reticuli, also known as Nova Reticuli 2020 was a naked eye nova in the constellation Reticulum discovered on July 15, 2020. Previously it was known as a VY Sculptoris type object with the designation MGAB-V207.

<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">DW Ursae Majoris</span> Variable star in the constellation Ursa Major

DW Ursae Majoris is an eclipsing binary star system in the northern circumpolar constellation of Ursa Major, abbreviated DW UMa. It is a cataclysmic variable of the SX Sextanis type, consisting of a compact white dwarf that is accreting matter from an orbiting companion star. The brightness of this source ranges from an apparent visual magnitude of 13.6 down to magnitude 18, which is too faint to be viewed with the naked eye. The distance to this system is approximately 1,920 light years 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 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 .
  3. 1 2 3 4 RX 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 2009-06-30.
  4. ↑ Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (2000), "The Tycho-2 catalogue of the 2.5 million brightest stars", Astronomy & Astrophysics, 355: L27–L30, Bibcode:2000A&A...355L..27H.
  5. ↑ Kraft, R. P. (March 1962). "Binary Stars among Cataclysmic Variables. I. U Geminorum Stars (dwarf Novae)". Astrophysical Journal. 135: 408. Bibcode:1962ApJ...135..408K. doi:10.1086/147280.
  6. 1 2 Gaia Collaboration; Brown, A. G. A; Vallenari, A; Prusti, T; De Bruijne, J. H. J; Mignard, F; Drimmel, R; Babusiaux, C; Bailer-Jones, C. A. L; Bastian, U; Biermann, M; Evans, D. W.; Eyer, L; Jansen, F; Jordi, C; Katz, D; Klioner, S. A.; Lammers, U; Lindegren, L; Luri, X; O'Mullane, W; Panem, C; Pourbaix, D; Randich, S; Sartoretti, P; Siddiqui, H. I.; Soubiran, C; Valette, V; Van Leeuwen, F; et al. (2016). "Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties". Astronomy & Astrophysics. 595: A2. arXiv: 1609.04172 . Bibcode:2016A&A...595A...2G. doi:10.1051/0004-6361/201629512. S2CID   1828208.
  7. ↑ Kaitchuck, R. H. (1989), "The Orbital Period of RX Andromedae", Publications of the Astronomical Society of the Pacific, 101: 1129, Bibcode:1989PASP..101.1129K, doi: 10.1086/132587 .
  8. 1 2 3 4 5 Sepinsky, J. F.; Sion, E. M.; Szkody, P.; Gänsicke, B. T. (2002), "Hubble Space Telescope Spectroscopy of the Dwarf Nova RX Andromedae during Outburst Rise and Decline", The Astrophysical Journal, 574 (2): 937–941, Bibcode:2002ApJ...574..937S, doi: 10.1086/341009 .
  9. 1 2 3 4 Harrison, T. E. (2018), "The Identification of Hydrogen-deficient Cataclysmic Variable Donor Stars", The Astrophysical Journal, 861 (2): 102, arXiv: 1806.04612 , Bibcode:2018ApJ...861..102H, doi: 10.3847/1538-4357/aacbd9 , S2CID   119531169.
  10. 1 2 3 Schreiber, M. R.; Gänsicke, B. T.; Mattei, J. A. (2002), "RX And: An intermediate between Z Cam and VY Scl stars", Astronomy and Astrophysics, 384: L6–L9, Bibcode:2002A&A...384L...6S, doi: 10.1051/0004-6361:20020122 .
  11. ↑ Coppejans, D. L.; Körding, E. G.; Miller-Jones, J. C. A.; Rupen, M. P.; Sivakoff, G. R.; Knigge, C.; Groot, P. J.; Woudt, P. A.; Waagen, E. O.; Templeton, M. (2016). "Dwarf nova-type cataclysmic variable stars are significant radio emitters". Monthly Notices of the Royal Astronomical Society. 463 (2): 2229–2241. arXiv: 1608.06295 . Bibcode:2016MNRAS.463.2229C. doi:10.1093/mnras/stw2133. S2CID   31287217.


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