UX Ursae Majoris

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UX Ursae Majoris
UXUMaLightCurve.png
A visual band light curve for UX Ursae Majoris, adapted from de Miguel et al. (2016). [1] The top plot shows the variation over several weeks, and the bottom plot shows the mean light curve over one orbital period.
Observation data
Epoch J2000.0       Equinox J2000.0
Constellation Ursa Major
Right ascension 13h 36m 40.953s [2]
Declination +51° 54′ 49.42″ [2]
Apparent magnitude  (V)12.57 to 14.15 [3]
Characteristics
Spectral type sdOB [4] + M4+ [5]
Variable type β Per, nova-like [3]
Astrometry
Radial velocity (Rv)112.0 [6]  km/s
Proper motion (μ)RA: −41.614  mas/yr [2]
Dec.: 17.180  mas/yr [2]
Parallax (π)3.4252 ± 0.0157  mas [2]
Distance 952 ± 4  ly
(292 ± 1  pc)
Orbit [7]
Period (P)4.72 hours
Semi-major axis (a)1.51 – 1.61  R☉
Inclination (i)65 – 75°
Semi-amplitude (K1)
(primary)		113±11 km/s
Semi-amplitude (K2)
(secondary)		262±14 km/s
Details
White dwarf
Mass 0.47 [8]   M☉
Radius 9,700 [8]   km
Surface gravity (log g)7.7 [9]   cgs
Temperature 20,000 [9]   K
Donor star
Mass 0.47 [8]   M☉
Radius 0.496 – 0.697 [9]   R☉
Surface gravity (log g)−4.65 – 4.73 [9]   cgs
Accretion disk
Radius 0.488 [9]   R☉
Temperature 88,450±21,230 [4]   K
Other designations
UX UMa, AAVSO 1332+52 [10]
Database references
SIMBAD data

UX Ursae Majoris is an Algol type binary star system in the northern circumpolar constellation of Ursa Major. It is classified as a nova-like variable star similar to DQ Herculis, although no eruptions have been reported. [11] Since its discovery in 1933, this system has been the subject of numerous studies attempting to determine its properties. [12] The combined apparent visual magnitude of UX UMa ranges from 12.57 down to 14.15. [3] The system is located at a distance of approximately 952  light years from the Sun based on parallax, [2] and is drifting further away with a radial velocity of 112 km/s. [6]

This system was found to be an eclipsing binary by the Soviet astronomer S. Belyavsky in 1933. At the time, the period of 4.73 hours was the shortest known for a binary star system. [12] M. Zverev and B. Kukarkin published elements from a light curve made from visual observations in 1937, while in 1939 V. A. Krat at Pulkovo Observatory produced a solution based on his photographic observations. [13] G. P. Kuiper in 1941 classified the star as a B3 subdwarf. [14] O. Struve in 1948 noted that the system underwent significant variations in its spectrum. [15] A. P. Linnell produced the first photoelectric light curve of the system in 1950, finding that the brightness underwent an increase just prior to the primary eclipse. He also noted that the system underwent rapid light variation. [13]

Observations of this system up to 1962 showed the period was changing: it increased up until 1953 then began decreasing. The depth of the eclipse was found to vary with wavelength, decreasing in depth with increasing wavelength possibly due to contributions by a cooler stellar component or surrounding material. [16] M. F. Walker and G. H. Herbig in 1954 suggested that the hump in the light curve is due to a hot spot. In 1974, R. E. Nather and E. L. Robinson proposed that the hot component is a white dwarf surrounded by a optically thick, orbiting disk of gas. The hot spot on the disk is formed by a stream of gas from the donor secondary star, and is the main source of the rapid flickering from the system. [14] The observed light curve can be reproduced by an orbital inclination of ~75° to the line of sight to the earth, with the white dwarf being almost completely obscured by its accretion disk. [11]

UX UMa is considered an archetypal example of nova-like variables that are always in a high accretion state, showing bright steady disks. [17] A photometric study of the system during 2015 found a cyclical signal with a mean period of 3.680 days and an amplitude of 0.44 in magnitude. This is interpreted as retrograde nodal precession of the accretion disk. [1] The infalling matter is creating a compact clump in the accretion disk. This is shielding illumination from the hot inner disk, forming a dark spot. Doppler tomography of the disk shows a spiral structure. [7] Observations during 1999 showed spectral features characteristic of an SW Sextantis variable, but at other times these features disappeared. [7]

Related Research Articles

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Omicron Ursae Majoris, formally named Muscida, is a star system in the northern circumpolar constellation of Ursa Major. It has an apparent visual magnitude of +3.35 and is located at a distance of around 179 light-years from the Sun. In 2012, an exoplanet designated Omicron Ursae Majoris Ab was found to be orbiting the primary.

<span class="mw-page-title-main">S Antliae</span> Star in the constellation Antlia

S Antliae is a W Ursae Majoris-type eclipsing binary star in Antlia.

<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">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">RW Aurigae</span> Young binary star system in the constellation Auriga

RW Aurigae is a young binary system in the constellation of Auriga about 530 light years away, belonging to the Taurus-Auriga association of the Taurus Molecular Cloud. RW Aurigae B was discovered in 1944.

<span class="mw-page-title-main">TU Ursae Majoris</span>

TU Ursae Majoris is a variable star in the northern circumpolar constellation of Ursa Major. It is classified as a Bailey-type 'ab' RR Lyrae variable with a period of 0.557648 days that ranges in brightness from apparent visual magnitude of 9.26 down to 10.24. The distance to this star is approximately 2,090 light years based on parallax measurements. It is located near the north galactic pole at a distance that indicates this is a member of the galactic halo.

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

TX Ursae Majoris is an eclipsing binary star system in the northern circumpolar constellation of Ursa Major. With a combined apparent visual magnitude of 6.97, the system is too faint to be readily viewed with the naked eye. The pair orbit each other with a period of 3.063 days in a circular orbit, with their orbital plane aligned close to the line of sight from the Earth. During the primary eclipse, the net brightness decreases by 1.74 magnitudes, while the secondary eclipse results in a drop of just 0.07 magnitude. TX UMa is located at a distance of approximately 780 light years from the Sun based on parallax measurements, but is drifting closer with a mean radial velocity of −13 km/s.

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

XY Ursae Majoris is a short period binary star system in the northern circumpolar constellation of Ursa Major. It is an eclipsing binary with a baseline apparent visual magnitude of 9.50. The system is located at a distance of 221.5 light years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −10 km/s. It has a relatively high proper motion, traversing the celestial sphere at the angular rate of 0.191″·yr−1.

<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">CQ Tauri</span> Star in the constellation Taurus

CQ Tauri is a young variable star in the equatorial constellation of Taurus. It is too faint to be visible to the naked eye with an apparent visual magnitude that ranges from 8.7 to 12.25. The distance to this star is approximately 487 light years based on parallax measurements, and it is drifting further away with a radial velocity of ~23 km/s. It appears to be part of the T-association Tau 4. CQ Tauri lies close enough to the ecliptic to undergo lunar occultations.

<span class="mw-page-title-main">AH Virginis</span> Star in the constellation Virgo

AH Virginis is a contact binary star system in the equatorial constellation of Virgo, abbreviated AH Vir. It is a variable star with a brightness that peaks at an apparent visual magnitude of 9.18, making it too faint to be viewed with the naked eye. The distance to this system is approximately 338 light years based on parallax measurements, and it is drifting further away with a mean radial velocity of 7 km/s. O. J. Eggen in 1969 included this system as a probable member of the Wolf 630 group of co-moving stars.

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

VV Ursae Majoris is a binary star system in the northern circumpolar constellation of Ursa Major, abbreviated VV UMa. It is a variable star system with a brightness that cycles around an apparent visual magnitude of 10.19, making it too faint to be visible to the naked eye. The system is located at a distance of approximately 1,500 light years based on parallax measurements.

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

AW Ursae Majoris is a binary star system in the northern circumpolar constellation of Ursa Major, abbreviated AW UMa. It is an A-type W Ursae Majoris variable with an apparent visual magnitude of 6.83, which is near the lower limit of visibility to the naked eye. This is an eclipsing binary with the brightness dropping to magnitude 7.13 during the primary eclipse and to 7.08 with the secondary eclipse. Parallax measurements give a distance estimate of 221 light years from the Sun. It is drifting closer to the Sun with a radial velocity of approximately −17 km/s. The system has a high proper motion, traversing the celestial sphere at the rate of 0.216 arc second per annum.

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

BE Ursae Majoris is a binary star system in the northern circumpolar constellation of Ursa Major, abbreviated BE UMa. The two components are an unusual M-class dwarf star and a subdwarf O star, borderline white dwarf. It is classified as a detached Algol variable and ranges in brightness from an apparent visual magnitude of 14.8 down to 17.8. This is too faint to be visible to the naked eye. The distance to this system is approximately 4,600 light years based on parallax measurements.

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

CQ Ursae Majoris is a variable star in the northern circumpolar constellation of Ursa Major, abbreviated CQ UMa. It is sometimes identified as HR 5153 from the Bright Star Catalogue or HD 119213 in the Henry Draper Catalogue; CQ UMa is the variable star designation. The star ranges in apparent visual magnitude from 6.28 to 6.30, which is bright enough to be dimly visible to the naked eye. It is located at a distance of 296 light years from the Sun based on parallax measurements.

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

DM Ursae Majoris is a binary star system in the northern circumpolar constellation of Ursa Major, abbreviated DM UMa. It is sometimes identified by the Bonner Durchmusterung catalogue designation BD +61 1211; DM UMa is the variable star designation. The system has a combined apparent visual magnitude of 9.29, which is too faint to be visible to the naked eye. Based on parallax measurements, the system is located at a distance of approximately 606 light years from the Sun, but it is drifting closer with a heliocentric radial velocity of −7 km/s.

<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.

References

  1. 1 2 de Miguel, E.; et al. (April 2016), "Accretion-disc precession in UX Ursae Majoris", Monthly Notices of the Royal Astronomical Society, 457 (2): 1447–1455, arXiv: 1512.08687 , Bibcode:2016MNRAS.457.1447D, doi:10.1093/mnras/stv3014.
  2. 1 2 3 4 5 6 Brown, A. G. A.; et al. (Gaia collaboration) (2021), "Gaia Early Data Release 3: Summary of the contents and survey properties", Astronomy & Astrophysics , 649: A1, arXiv: 2012.01533 , Bibcode:2021A&A...649A...1G, doi: 10.1051/0004-6361/202039657 , S2CID   227254300 (Erratum:  doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  3. 1 2 3 Samus', N. N; et al. (2017), "General catalogue of variable stars", Astronomy Reports, GCVS 5.1, 61 (1): 80, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID   125853869.
  4. 1 2 Lei, Zhenxin; et al. (April 2019), "Searching for hot subdwarf stars from the LAMOST Spectra. II. Pure spectroscopic identification method for hot subdwarfs", Publications of the Astronomical Society of Japan, 71 (2): 41, arXiv: 1907.00132 , Bibcode:2019PASJ...71...41L, doi:10.1093/pasj/psz006.
  5. ↑ Putte, D. V.; et al. (2003), "A spectroscopic search for faint secondaries in cataclysmic variables", Monthly Notices of the Royal Astronomical Society, 342 (1): 151–162, arXiv: astro-ph/0302507 , Bibcode:2003MNRAS.342..151V, doi:10.1046/j.1365-8711.2003.06524.x, S2CID   119383913.
  6. 1 2 Duflot, M.; et al. (1995), "Vitesses radiales. Catalogue WEB: Wilson Evans Batten. Subtittle: Radial velocities: The Wilson-Evans-Batten catalogue", Astronomy and Astrophysics Supplement Series, 114: 269, Bibcode:1995A&AS..114..269D.
  7. 1 2 3 Neustroev, V. V.; et al. (2011), "Dark spot, spiral waves and the SW Sextantis behaviour: It is all about UX Ursae Majoris", Monthly Notices of the Royal Astronomical Society, 410 (2): 963–977, arXiv: 1006.3106 , Bibcode:2011MNRAS.410..963N, doi:10.1111/j.1365-2966.2010.17495.x, S2CID   118555373.
  8. 1 2 3 Noebauer, Ulrich M.; et al. (August 2010), "The Geometry and Ionization Structure of the Wind in the Eclipsing Nova-like Variables RW Tri and UX UMa", The Astrophysical Journal, 719 (2): 1932–1945, arXiv: 1007.0209 , Bibcode:2010ApJ...719.1932N, doi:10.1088/0004-637X/719/2/1932, S2CID   119208187.
  9. 1 2 3 4 5 Linnell, Albert P.; et al. (2008), "Modeling UX Ursae Majoris: An Abundance of Challenges", The Astrophysical Journal, 688 (1): 568–582, arXiv: 0807.3920 , Bibcode:2008ApJ...688..568L, doi:10.1086/592104, S2CID   1648147.
  10. ↑ "UX UMa", SIMBAD , Centre de données astronomiques de Strasbourg , retrieved 2022-02-27.
  11. 1 2 Petterson, J. A. (October 1980), "Accretion disks in cataclysmic variables. I. The eclipse-related phase shifts in DQ Herculis and UX Ursae Majoris", Astrophysical Journal, 241: 247–256, Bibcode:1980ApJ...241..247P, doi:10.1086/158337.
  12. 1 2 Smak, J. (January 1994), "Eclipses in Cataclysmic Variables with Stationary Accretion Disks. II. UX UMa", Acta Astronomica, 44: 59–74, Bibcode:1994AcA....44...59S.
  13. 1 2 Linnell, Albert P. (1950), "A Study of UX Ursae Majoris", Harvard College Observatory Circular, 455: 1–13, Bibcode:1950HarCi.455....1L.
  14. 1 2 Nather, R. E.; Robinson, E. L. (June 1974), "Coherent oscillations in UX Ursae Majoris", Astrophysical Journal, 190: 637–651, Bibcode:1974ApJ...190..637N, doi:10.1086/152921.
  15. ↑ Struve, Otto (July 1948), "The Spectrum of the Eclipsing Binary UX Ursae Majoris", Astrophysical Journal, 108: 153, Bibcode:1948ApJ...108..153S, doi: 10.1086/145052 .
  16. ↑ Krzeminski, W.; Walker, Merle F. (July 1963), "Photoelectric Observations of UX Ursae Majoris, 1955-1962", Astrophysical Journal, 138: 146, Bibcode:1963ApJ...138..146K, doi: 10.1086/147624 .
  17. ↑ 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.

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