V455 Andromedae

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V455 Andromedae
V455AndLightCurve.png
The visual band light curve of the 2007 outburst of V455 Andromedae, from AAVSO data and Kato et al. (2008) [1] [2]
Observation data
Epoch J2000       Equinox J2000
Constellation Andromeda
Right ascension 23h 34m 01.4485s [3]
Declination +39° 21′ 40.8665″ [3]
Apparent magnitude  (V)8.5 – 16.5 variable [4]
Characteristics
Spectral type pec(UG) [5]
Apparent magnitude  (B)16.22 [6]
Apparent magnitude  (R)16.14 [6]
Apparent magnitude  (G)16.0635 [3]
Apparent magnitude  (J)15.528 [7]
Apparent magnitude  (H)15.199 [7]
Apparent magnitude  (K)14.567 [7]
Variable type Dwarf Nova [5]
Astrometry
Proper motion (μ)RA: −57.141±0.075 [3]   mas/yr
Dec.: −139.317±0.060 [3]   mas/yr
Parallax (π)13.2403 ± 0.0556  mas [3]
Distance 246 ± 1  ly
(75.5 ± 0.3  pc)
Orbit [8]
Period (P)81.08 minutes
Inclination (i)75°
Semi-amplitude (K1)
(primary)		36 km/s
Details [4]
White dwarf
Mass 0.6  M☉
Rotation 67.61970396±0.00000072 s
Donor star
Mass 0.07  M☉
Other designations
2MASS J23340144+3921408
Database references
SIMBAD data

V455 Andromedae (often abbreviated to V455 And) 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.

Contents

System

When it was discovered in 2003, during the quiescent phase, V455 Andromedae was classified as a cataclysmic variable, since its spectrum is similar to U Geminorum. V455 Andromedae is therefore a binary star where the primary is a white dwarf that is accreting matter from the secondary donor star. The rotation period of the white dwarf, slightly less than 68 seconds, is shorter than the orbital period so the white dwarf must possess a magnetic field channelling the material from the accretion disk to the poles of the white dwarf. This qualifies V455 Andromedae as a cataclysmic variable of the intermediate polar type. The spin period is expected to become shorter with time, but to date only upper limits on its decreasing trend has been determined. [4]

The mass of the donor star is only 0.07 M☉. This low mass makes V455 Andromedae similar to WZ Sagittae dwarf novae, which are expected to have a long period between outbursts. [4]

Variability

Eclipses in the light curve of V455 Andromedae revealed the binary nature of this star and its orbital period. Only one outburst event has been observed so far: V455 Andromedae brightened by 8 magnitudes during 2007. Such a large increase in brightness implies that this was a superoutburst, and V455 Andromedae is therefore a dwarf nova of the SU Ursae Majoris type. Superhumps were observed during the outburst. [4]

Superhumps have also been reported during quiescence, known as permanent superhumps. An 83.38  min positive superhump was observed in 2000 - 2003, [8] while 80.376 min negative superhumps were seen in 2013 and 2014. This is the first time negative superhumps have been detected in WZ sagittae dwarf novae during quiescence. [9]

V455 Andromedae shows spectroscopic variations in its line profiles with a period of 3.5 hours. This is taken to be the precession period of a warped accretion disk, possibly retrograde precession. [9]

The white dwarf primary pulsates radially with periods of about five or six minutes. [8] [10] These are considered to be incoherent, or possibly to consist of too many different periods to be analysed. [9] [10] Further brightness oscillations are seen with a period of 67.28  s , which is a beat period between the spin period and the spectroscopic period. [9]

The brightness of V455 And has been gradually fading since 2008, mainly due to the gradual cooling of the white dwarf and the hot spot on the accretion disk and/or lower mass transfer, until an equilibrium level has been reached. [10]

Related Research Articles

<span class="mw-page-title-main">Dwarf nova</span> Cataclysmic variable star, consisting of a close binary star system

A dwarf nova, or U Geminorum variable, is one of several types of cataclysmic variable star, consisting of a close binary star system in which one of the components is a white dwarf that accretes matter from its companion. Dwarf novae are dimmer and repeat more frequently than "classical" novae.

<span class="mw-page-title-main">Symbiotic binary</span> Class of astronomical objects

A symbiotic binary is a type of binary star system, often simply called a symbiotic star. They usually contain a white dwarf with a companion red giant. The cool giant star loses material via Roche lobe overflow or through its stellar wind, which flows onto the hot compact star, usually via an accretion disk.

<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.

<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">EK Trianguli Australis</span> Star system in the constellation Triangulum Australe

EK Trianguli Australis is a star in the constellation Triangulum Australe. It is a dwarf nova of the SU Ursae Majoris type that officially classified as such in 1980, after the characteristic eruptions of a short eruption and a supereruption were observed in May 1978 and June 1979 respectively. These systems are characterised by frequent eruptions and less frequent supereruptions. The former are smooth, while the latter exhibit short "superhumps" of heightened activity. The distance of the system has been assumed at 180 parsecs from the Solar System, for the donor star. Spectroscopic analysis and calculation gave an estimate of 125 parsecs.

<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">BV Centauri</span> Star in the constellation Centaurus


BV Centauri is a cataclysmic variable binary star in the constellation Centaurus. It is a dwarf nova, and undergoes rapid increases in brightness that are recurrent with a mean period of 150 days. This period seems to have increased in the last few decades. During quiescence, its visual apparent magnitude is about 13, with variations of a few tenths of magnitude over an orbit due to differences in the star's visible surface area, brightening to a maximum magnitude of 10.7 during outbursts. From its luminosity, it is estimated that the system is about 500 parsecs (1,600 ly) away from Earth. A Gaia parallax of 2.81 mas has been measured, corresponding to about 360 pc.

<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">TU Mensae</span> Star in the constellation Mensa

TU Mensae is a cataclysmic variable star of in the constellation Mensa. A close binary, it consists of a white dwarf and low-mass star orbiting each other in 2 hours 49 minutes. The stars are close enough that the white dwarf strips material off the other star, creating an accretion disc that periodically ignites with a resulting brightening of the system. These result in an increase in brightness lasting around a day every 37 days. Brighter outbursts, known as superhumps, last 5-20 days and take place every 194 days. The properties of TU Mensae have been difficult to calculate, as the calculated mass ratio between the two stars mean there should not be superhumps.

<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">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">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">GI Monocerotis</span> 1918 Nova in the constellation Monoceros

GI Monocerotis, also known as Nova Monocerotis 1918, was a nova that erupted in the constellation Monoceros during 1918. It was discovered by Max Wolf on a photographic plate taken at the Heidelberg Observatory on 4 February 1918. At the time of its discovery, it had a photographic magnitude of 8.5, and had already passed its peak brightness. A search of plates taken at the Harvard College Observatory showed that it had a photographic magnitude of 5.4 on 1 January 1918, so it would have been visible to the naked eye around that time. By March 1918 it had dropped to ninth or tenth magnitude. By November 1920 it was a little fainter than 15th magnitude.

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

SW Ursae Majoris is a cataclysmic binary star system in the northern circumpolar constellation of Ursa Major, abbreviated SW UMa. During quiescence it has an apparent visual magnitude of 16.5–17, which is too faint to be visible to the naked eye. Based on parallax measurements, it is located at a distance of approximately 526 light years from the Sun.

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

ER Ursae Majoris is a variable star in the northern circumpolar constellation of Ursa Major, abbreviated ER UMa. It is a prototype system for a subclass of SU Ursae Majoris dwarf novae. The system ranges in brightness from a peak apparent visual magnitude of 12.4 down to 15.2, which is too faint to be visible to the naked eye. The distance to this system, based on parallax measurements, is approximately 1,163 light years.

References

  1. ↑ "Download Data". aavso.org. AAVSO. Retrieved 1 October 2021.
  2. ↑ Kato, Taichi; Maehara, Hiroyuki; Monard, Berto (August 2008). "Late Superhumps in WZ Sge-Type Dwarf Novae". Publications of the Astronomical Society of Japan. 60 (4): L23–L26. arXiv: 0806.4248 . doi: 10.1093/pasj/60.4.L23 . Retrieved 12 October 2021.
  3. 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.
  4. 1 2 3 4 5 Mukadam, Anjum S.; Pyrzas, Stylianos; Townsley, D. M.; Gänsicke, B. T.; Hermes, J. J.; Szkody, Paula; Kemp, Jonathan; Patterson, J.; Ding, Claire; Wolf, Katie; Gemma, Marina; Karamehmetoglu, Emir; Rock, John (2016). "Constraining the Angular Momentum Evolution of V455 Andromedae" (PDF). The Astrophysical Journal. 821 (1): 14. Bibcode:2016ApJ...821...14M. doi: 10.3847/0004-637X/821/1/14 . S2CID   124885011.
  5. 1 2 N. N. Samus; O. V. Durlevich; et al. "V455 And database entry". Combined General Catalog of Variable Stars (2017 ed.). CDS . Retrieved 2018-11-12.
  6. 1 2 Database entry, VizieR Online Data Catalog: UCAC4 Catalogue (Zacharias+, 2012), N. Zacharias et al., CDS ID I/322A Accessed on line 2018-11-06.
  7. 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.
  8. 1 2 3 Araujo-Betancor, S.; Gänsicke, B. T.; Hagen, H.-J.; Marsh, T. R.; Harlaftis, E. T.; Thorstensen, J.; Fried, R. E.; Schmeer, P.; Engels, D. (2005). "HS 2331+3905: The cataclysmic variable that has it all". Astronomy & Astrophysics. 430 (2): 629–642. arXiv: astro-ph/0410223 . doi:10.1051/0004-6361:20041736. S2CID   53724468.
  9. 1 2 3 4 Kozhevnikov, V. P. (2015). "Extensive photometry of the WZ Sge-type dwarf nova V455 and (HS2331+3905): Detection of negative superhumps and coherence features of the short-period oscillations". New Astronomy. 41: 59–66. arXiv: 1506.03217 . Bibcode:2015NewA...41...59K. doi:10.1016/j.newast.2015.06.002. S2CID   118634431.
  10. 1 2 3 Ghaderpour, E.; Ghaderpour, S. (2020). "Least-squares spectral and wavelet analyses of V455 Andromedae time series: The life after the super-outburst". Publications of the Astronomical Society of the Pacific. 132 (1017): 1017. doi:10.1088/1538-3873/abaf04. hdl: 11573/1655309 . S2CID   234674260.
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