BV Centauri

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BV Centauri
BVCenLightCurve.png
A near infrared (I band) light curve for BV Centauri from ASAS data, adapted from Kiraga (2012) [1]
Observation data
Epoch J2000       Equinox J2000
Constellation Centaurus
Right ascension 13h 31m 19.485s [2]
Declination −54° 58′ 33.52″ [2]
Apparent magnitude  (V)13.05 [3] (10.7 to 14.0) [4]
Characteristics
Spectral type G5-G8IV-V (secondary) [3]
U−B color index -0.22 [3]
B−V color index 0.77 [3]
Variable type SS Cyg [4]
Astrometry
Radial velocity (Rv)-22.3 [5]  km/s
Proper motion (μ)RA: -25.8 [2]   mas/yr
Dec.: -1.4 [2]   mas/yr
Parallax (π)2.81 ± 0.38  mas [6]
Distance approx. 1,200  ly
(approx. 360  pc)
Absolute magnitude  (MV)+3.0 - +5.8 [6]
Orbit
Period (P)0.611±0.002 days [5]
Semi-major axis (a)2.53×1011 cm(0.017 au) [7]
Inclination (i)53±4, [5] 62±5 [7] °
Semi-amplitude (K1)
(primary)		128±3 [7] km/s
Semi-amplitude (K2)
(secondary)		137.3±0.3 [5] km/s
Details
Primary (white dwarf)
Mass 1.18+0.28
−0.16 [5]   M☉
Surface gravity (log g)8.3 [8]   cgs
Temperature 40000 ± 1000 [8]   K
Rotational velocity (v sin i)500 ± 100 [8]  km/s
Secondary
Mass 1.05+0.23
−0.14 [5]   M☉
Radius 1.41 ± 0.04 [7]   R☉
Surface gravity (log g)3.5 [5]   cgs
Temperature 5250 [5]   K
Other designations
BV  Centauri, 2MASS  J13311951-5458335, AAVSO  1325-54 [9]
Database references
SIMBAD data


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. [10] 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 (ellipsoidal variability), [7] brightening to a maximum magnitude of 10.7 during outbursts. [4] From its luminosity, it is estimated that the system is about 500 parsecs (1,600 ly) away from Earth. [3] [7] A Gaia parallax of 2.81 mas has been measured, corresponding to about 360 pc. [6]

Cataclysmic variables are short-period binary systems in which a white dwarf primary accretes matter from a secondary star. For BV Centauri, the white dwarf and its companion have estimated masses of 1.18 and 1.05 times the mass of the Sun respectively, [5] although alternate, conflicting mass measurements were reported too. [11] The secondary is a conventional star with a spectral type of G5-G8IV-V and it is assumed to contribute to half of the visual luminosity of the system. It is thought to have a radius of 1.4 R☉ and so to be significantly evolved away from the zero age main sequence. [3] [7] The reconstruction of its surface by Doppler imaging revealed it to be a highly magnetically active star, with about 25% of its surface covered in starspots which are much more abundant on the hemisphere facing the white dwarf. Furthermore, a prominence was detected above the secondary star's surface, also in the side facing the white dwarf. [5] The white dwarf primary can be observed clearly at ultraviolet wavelengths where it is the strongest source. Any accretion disk in the system appears relatively faint. [8]

The system has a period of 0.611179 days (16.7 hours), one of the longest periods for a dwarf nova, and is inclined by 53 ± 4° in relation to the plane of the sky. [5]

It has been noted that BV Centauri's light curve during outbursts has anomalous behavior for a dwarf nova, with a long interval of up to 15 days before reaching peak brightness and no plateau at maximum brightness, and it has been compared to the classic nova GK Persei. Based on this, it has been proposed that BV Centauri could have generated an unobserved nova outburst in the 19th century, which was missed by the observers at the time. [10] [12]

Related Research Articles

<span class="mw-page-title-main">Nova</span> Nuclear explosion in a white dwarf star

A nova is a transient astronomical event that causes the sudden appearance of a bright, apparently "new" star that slowly fades over weeks or months. All observed novae involve white dwarfs in close binary systems, but causes of the dramatic appearance of a nova vary, depending on the circumstances of the two progenitor stars. The main sub-classes of novae are classical novae, recurrent novae (RNe), and dwarf novae. They are all considered to be cataclysmic variable stars.

<span class="mw-page-title-main">V603 Aquilae</span> 1918 Nova event in the constellation Aquila

V603 Aquilae was a bright nova first observed in the constellation Aquila in 1918. It was the brightest "new star" to appear in the sky since Kepler's Supernova in 1604. Like all novae, it is a binary system, comprising a white dwarf and donor low-mass star in close orbit to the point of being only semidetached. The white dwarf sucks matter off its companion, which has filled its Roche lobe, onto its accretion disk and surface until the excess material is blown off in a thermonuclear event. This material then forms an expanding shell, which eventually thins out and disappears.

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

DQ Herculis, or Nova Herculis 1934, was a slow, bright nova occurring in the northern constellation of Hercules in December 1934. This cataclysmic variable star was discovered on 13 December 1934 by J. P. M. Prentice from Stowmarket, Suffolk. It reached peak brightness on 22 December 1934 with an apparent magnitude of 1.5. The nova remained visible to the naked eye for several months.

<span class="mw-page-title-main">DI Lacertae</span> 1910 Nova in the constellation Lacerta

DI Lacertae or Nova Lacertae 1910 was a nova in constellation Lacerta which appeared in 1910. It was discovered by Thomas Henry Espinell Compton Espin at Wolsingham Observatory on 30 Dec 1910, at which time it was an 8th magnitude object. Subsequent examination of pre-discovery photographic plates showed that the outburst occurred sometime between 17 November 1910 and 23 November 1910. It reached a peak brightness of magnitude 4.6 on 26 November 1910, making it visible to the naked eye. Before the nova event DI Lacertae was a 14th magnitude star, and by 1950 it had returned to 14th magnitude.

<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">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.

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">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">V803 Centauri</span> Star in the constellation Centaurus

V803 Centauri is a cataclysmic binary consisting of a dwarf helium star losing mass to a white dwarf. It is an example of the AM Canum Venaticorum type of cataclysmic variable 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">RW Ursae Minoris</span> Nova that appeared in 1956

RW Ursae Minoris is a cataclysmic variable star system that flared up as a nova in the constellation Ursa Minor in 1956.

<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">V392 Persei</span> Nova in the constellation Perseus

V392 Persei, also known as Nova Persei 2018, is a bright nova in the constellation Perseus discovered on April 29, 2018. It was previously known as a dwarf nova.

<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">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">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">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.

<span class="mw-page-title-main">DO Draconis/YY Draconis</span> Binary star in the constellation of Draco

YY Draconis and DO Draconis are separate identifiers for what is likely the same cataclysmic variable system in the northern constellation of Draco, abbreviated YY Dra and DO Dra, respectively. The DO Dra binary star system is classified as a U Geminorum variable that ranges in luminosity from an apparent visual magnitude of 10.0 down to 15.1. It is located at a distance of approximately 639 light years from the Sun.

References

  1. ↑ Kiraga, M. (March 2012). "ASAS Photometry of ROSAT Sources. I. Periodic Variable Stars Coincident with Bright Sources from the ROSAT All Sky Survey". Acta Astronomica. 62 (1): 67–95. arXiv: 1204.3825 . Bibcode:2012AcA....62...67K . Retrieved 28 November 2021.
  2. 1 2 3 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 and Astrophysics. 355: L27. Bibcode:2000A&A...355L..27H.
  3. 1 2 3 4 5 6 Vogt, N; Breysacher, J (February 1980). "The dwarf nova BV Centauri - A spectroscopic binary". Astrophysical Journal. 235: 945–954. Bibcode:1980ApJ...235..945V. doi: 10.1086/157699 .
  4. 1 2 3 Samus, N. N; Durlevich, O. V; et al. (January 2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/gcvs. 1. Bibcode:2009yCat....102025S. VizieR table entry
  5. 1 2 3 4 5 6 7 8 9 10 11 Watson, C. A; Steeghs, D; Shahbaz, T; Dhillon, V. S (December 2007). "Roche tomography of cataclysmic variables - IV. Star-spots and slingshot prominences on BV Cen". Monthly Notices of the Royal Astronomical Society. 382 (3): 1105–1118. arXiv: 0707.0739 . Bibcode:2007MNRAS.382.1105W. doi: 10.1111/j.1365-2966.2007.12173.x . S2CID   2073273.
  6. 1 2 3 Ramsay, Gavin; Schreiber, Matthias R; Gänsicke, Boris T; Wheatley, Peter J (2017). "Distances of cataclysmic variables and related objects derived from Gaia Data Release 1". Astronomy & Astrophysics. 604: A107. arXiv: 1704.00496 . Bibcode:2017A&A...604A.107R. doi:10.1051/0004-6361/201730679. S2CID   56464882.
  7. 1 2 3 4 5 6 7 Gilliland, R. L. (December 1982). "A time-resolved spectroscopic study and modeling of the dwarf nova BV Centauri". Astrophysical Journal. 263: 302–311. Bibcode:1982ApJ...263..302G. doi:10.1086/160504.
  8. 1 2 3 4 Sion, Edward M; Godon, Patrick; Cheng, Fuhua; Szkody, Paula (August 2007). "FUSE Observations of the Dwarf Novae UU Aql, BV Cen, and CH UMa in Quiescence". The Astronomical Journal. 134 (2): 886–895. arXiv: 0704.1133 . Bibcode:2007AJ....134..886S. doi:10.1086/518829. S2CID   14393007.
  9. ↑ "V* BV Cen -- Dwarf Nova". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2017-11-07.
  10. 1 2 Plummer, A; Horn, P (June 2009). "The Changing Nature of the Dwarf Nova BV Centauri". The Journal of the American Association of Variable Star Observers. 37 (1): 23. Bibcode:2009JAVSO..37...23P.
  11. ↑ Xu, Xiao-jie; Yu, Zhuo-li; Li, Xiang-Dong (2019). "The Fe Line Flux Ratio as a Diagnostic of the Maximum Temperature and the White Dwarf Mass of Cataclysmic Variables". The Astrophysical Journal. 878 (1): 53. arXiv: 1905.03399 . Bibcode:2019ApJ...878...53X. doi: 10.3847/1538-4357/ab1fe1 . S2CID   148571913.
  12. ↑ Menzies, J. W; Odonoghue, D; Warner, B (May 1986). "BV Centauri - Dwarf or classical nova?" . Astrophysics and Space Science. 122 (1): 73–80. Bibcode:1986Ap&SS.122...73M. doi:10.1007/BF00654382. S2CID   123400202.
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