Astronomy:SW Ursae Majoris
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Short description: Variable star in the constellation Ursa Major
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Ursa Major |
| Right ascension | 08h 36m 42.749s[2] |
| Declination | +53° 28′ 37.98″[2] |
| Apparent magnitude (V) | 9.7 to 16.5[3] |
| Characteristics | |
| Variable type | U Gem[3] |
| Astrometry | |
| Proper motion (μ) | RA: −28.713[2] mas/yr Dec.: 5.928[2] mas/yr |
| Parallax (π) | 6.2002 ± 0.0602[2] mas |
| Distance | 526 ± 5 ly (161 ± 2 pc) |
| Absolute magnitude (MV) | +4.9 (at maximum)[4] |
| Details | |
| White dwarf | |
| Mass | 0.61+0.06−0.04[5] M☉ |
| Radius | 0.0129+0.0009−0.0010[5] R☉ |
| Surface gravity (log g) | 8.01+0.11−0.09[5] cgs |
| Temperature | 13,854+189−131[5] K |
| donor | |
| Mass | 0.1[6] M☉ |
| Luminosity | 0.001[6] L☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
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.[8] Based on parallax measurements, it is located at a distance of approximately 526 light years from the Sun.[2]
The variable nature of this object was noted by L. Tseraskaya in 1909 when it increased in brightness to 10th magnitude.[9][10] It was determined to be a U Geminorum star, indicating this is a binary star system.[11] A short orbital period of 81.8 minutes was determined by A. W. Shafter and associates in 1986.[12] The same year, E. L. Robinson and associates detected superhumps with a period of 84.0 minutes.[1] Large amplitude quasi-periodic oscillations were observed by T. Kato and associates in 1992, which is a property of SU UMa-type dwarf novae.[13]
When the system is in a quiet period, it displays a periodicity of 15.9 minutes and has a marginal emission of soft X-rays. This is likely the rotation period of the white dwarf, and the system resembles an intermediate polar with a strongly-magnetized white dwarf as the accreting component.[8] It undergoes outbursts that vary in brightness and duration.[14] During quiescence, it is estimated that about 70% of the bolometric luminosity of the system is produced by the white dwarf, with almost all the rest produced by the accretion disk.[15]
References
- ↑ 1.0 1.1 Robinson, Edward L. et al. (February 1987), "Detection of Superhumps and Quasi-periodic Oscillations in the Light Curve of the Dwarf Nova SW Ursae Majoris", Astrophysical Journal 313: 772, doi:10.1086/165015, Bibcode: 1987ApJ...313..772R.
- ↑ 2.0 2.1 2.2 2.3 2.4 Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode: 2021A&A...649A...1G. Gaia EDR3 record for this source at VizieR.
- ↑ 3.0 3.1 Samus, N. N. et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1 61 (1): 80–88, doi:10.1134/S1063772917010085, Bibcode: 2017ARep...61...80S.
- ↑ Patterson, Joseph (2011), "Distances and absolute magnitudes of dwarf novae: Murmurs of period bounce", Monthly Notices of the Royal Astronomical Society 411 (4): 2695–2716, doi:10.1111/j.1365-2966.2010.17881.x, Bibcode: 2011MNRAS.411.2695P.
- ↑ 5.0 5.1 5.2 5.3 Pala, A. F. et al. (March 2022), "Constraining the evolution of cataclysmic variables via the masses and accretion rates of their underlying white dwarfs", Monthly Notices of the Royal Astronomical Society 510 (4): 6110–6132, doi:10.1093/mnras/stab3449, Bibcode: 2022MNRAS.510.6110P.
- ↑ 6.0 6.1 Povich, M. S. et al. (September 24, 2004), "Far Ultraviolet Spectroscopic Explorer Observations of the Dwarf Nova SW Ursae Majoris during Quiescence", arXiv 617 (1): pp. 500–507, doi:10.1086/425213, Bibcode: 2004ApJ...617..500P.
- ↑ "SW UMa". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=SW+UMa.
- ↑ 8.0 8.1 Soejima, Yuichi et al. (August 2009), "Photometry of Three Superoutbursts of the SU UMa-Type Dwarf Nova, SW Ursae Majoris", Publications of the Astronomical Society of Japan 61 (4): 659–674, doi:10.1093/pasj/61.4.659, Bibcode: 2009PASJ...61..659S.
- ↑ Ceraski, W. (December 1909), "Note sur un astre qui est probablement une étoile variable (44.1909 Ursae majoris)" (in Fr), Astronomische Nachrichten 183 (7): 109, doi:10.1002/asna.19091830705, Bibcode: 1909AN....183..109C, https://zenodo.org/record/1803660.
- ↑ Hornby, P. W. (October 1975), "Two U Geminorum variables: UV Per 1926–69 and SW UMa 1963–69", Journal of the British Astronomical Association 85: 528–531, Bibcode: 1975JBAA...85..528H.
- ↑ Wellmann, P. (1952), "Lichtkurve und Maximumspektrum des U Geminorum-Veränderlichen SW Ursae maioris. Mit 7 Textabbildungen" (in de), Zeitschrift für Astrophysik 31: 123, Bibcode: 1952ZA.....31..123W.
- ↑ Shafter, A. W. et al. (September 1986), "X-Ray and Optical Observations of the Ultrashort Period Dwarf Nova SW Ursae Majoris: A Likely New DQ Herculis Star", Astrophysical Journal 308: 765, doi:10.1086/164549, Bibcode: 1986ApJ...308..765S.
- ↑ Kato, Taichi et al. (October 1992), "Discovery of "Super-Quasi-Periodic Oscillations" during Superoutburst of Dwarf Nova SW Ursae Majoris", Publications of the Astronomical Society of Japan 44: L215–L219, Bibcode: 1992PASJ...44L.215K.
- ↑ Howell, Steve B. et al. (November 1995), "Ultraviolet Observations of SW Ursae Majoris, BC Ursae Majoris, and TV Corvi (1217--18): IUE Spectroscopy and Outburst Light Curves", Astrophysical Journal 453: 454, doi:10.1086/176407, Bibcode: 1995ApJ...453..454H.
- ↑ Urban, Joel A; Sion, Edward M (2006). "The Dwarf Novae during Quiescence". The Astrophysical Journal 642 (2): 1029–1041. doi:10.1086/501430. Bibcode: 2006ApJ...642.1029U.
Further reading
- Perez-Garcia, I. et al. (October 2021), "Observations with the BOOTES Network of the current outburst in the dwarf-nova SW UMa", The Astronomer's Telegram 14960: 1, Bibcode: 2021ATel14960....1P.
- İkis Gün, G. et al. (December 2013), "Preliminary results of the spectral analysis of Suzaku data of SW Ursae Majoris and BZ Ursae Majoris", New Astronomy 25: 1–6, doi:10.1016/j.newast.2013.03.011, Bibcode: 2013NewA...25....1I.
- Waagen, E. O. et al. (September 2006), Green, D. W. E., ed., "SW Ursae Majoris", IAU Circular 8748: p. 2, Bibcode: 2006IAUC.8748....2W.
- Povich, M. S. et al. (December 2004), "Far Ultraviolet Spectroscopic Explorer Observations of the Dwarf Nova SW Ursae Majoris during Quiescence", The Astrophysical Journal 617 (1): 500–507, doi:10.1086/425213, Bibcode: 2004ApJ...617..500P.
- Burleigh, M. R. et al. (August 2001), "A ROSAT WFC observation of SW UMa: the EUV behaviour of dwarf novae in superoutburst explained", Monthly Notices of the Royal Astronomical Society 325 (4): 1458–1462, doi:10.1046/j.1365-8711.2001.04551.x, Bibcode: 2001MNRAS.325.1458B.
- Pavlenko, E. P. et al. (October 2000), "CCD Photometry of the Cataclysmic Variable SW Ursae Majoris at a Late Stage of the 2000 Superoutburst", Astrophysics (English translation of Astrofizika) 43 (4): pp. 419–429, doi:10.1023/A:1010914924206, Bibcode: 2000Ap.....43..419P.</ref>
- Mattei, J. A. et al. (February 2000), Green, D. W. E., ed., "SW Ursae Majoris", IAU Circular 7365: p. 2, Bibcode: 2000IAUC.7365....2M.
- Gänsicke, B. T.; Koester, D. (June 1999), "SW Ursae Majoris, CU Velorum and AH Mensae: three more accreting white dwarfs unveiled?", Astronomy and Astrophysics 346: 151–157, Bibcode: 1999A&A...346..151G.
- Nogami, Daisaku et al. (April 1998), "CCD Photometry of SW Ursae Majoris during the 1996 Superoutburst", Publications of the Astronomical Society of Japan 50 (2): 297–302, doi:10.1093/pasj/50.2.297, Bibcode: 1998PASJ...50..297N.
- Mobberley, M. P. et al. (April 1997), "C. R. d'Esterre and the mysteries of UV and UW Per", Journal of the British Astronomical Association 107 (2): 65–71, Bibcode: 1997JBAA..107...65M.
- Semeniuk, I. et al. (January 1997), "CCD Photometry of SW Ursae Majoris during the 1996 Superoutburst", Acta Astronomica 47: 201–209, Bibcode: 1997AcA....47..201S.
- Rosen, S. R. et al. (August 1994), "ROSAT constraints on the intermediate polar candidates V426 Oph, SW UMa and 1H 0709-360.", Monthly Notices of the Royal Astronomical Society 269 (4): 913–920, doi:10.1093/mnras/269.4.913, Bibcode: 1994MNRAS.269..913R, https://figshare.com/articles/journal_contribution/ROSAT_constraints_on_the_intermediate_polar_candidates_V_426_Oph_SW_UMa_and_1H0709_360/10166150/1/files/18321392.pdf.
- Szkody, Paula et al. (May 1988), "EXOSAT and IUE Observations of SW UMa during Superoutburst", Astrophysical Journal 328: 243, doi:10.1086/166286, Bibcode: 1988ApJ...328..243S.
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