ER Ursae Majoris
 A visual band light curve for ER Ursae Majoris. The main plot shows a normal outburst in 2004, with the estimated value for the unobserved maximum plotted in red. The inset plot shows superhump oscillations. Adapted from Zhao et al. (2006).[1] | |
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Ursa Major |
| Right ascension | 09h 47m 11.941s[2] |
| Declination | +51° 54′ 08.95″[2] |
| Apparent magnitude (V) | 12.4 to 15.2[3] |
| Characteristics | |
| Variable type | Dwarf nova(?)[3] |
| Astrometry | |
| Proper motion (μ) | RA: 33.659 mas/yr[2] Dec.: −6.209 mas/yr[2] |
| Parallax (π) | 2.8039±0.0205 mas[2] |
| Distance | 1,163 ± 9 ly (357 ± 3 pc) |
| Orbit[4] | |
| Period (P) | 0.06366±0.00003 d |
| Eccentricity (e) | 0.00 (assumed) |
| Inclination (i) | 18–50[5]° |
| Periastron epoch (T) | 2,449,740.0637±0.0008 HJD |
| Argument of periastron (ω) (secondary) | 0.00 (assumed)° |
| Semi-amplitude (K1) (primary) | 48±4 km/s |
| Details | |
| White dwarf | |
| Mass | 1.0±0.2[5] M☉ |
| Temperature | 32,000[5] K |
| Donor star | |
| Mass | 0.10[5] M☉ |
| Other designations | |
| PG 0943+521, ER UMa, AAVSO 0939+52, GSC 03439-00550, 2MASS J09471193+5154089[6] | |
| Database references | |
| SIMBAD | data |
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.[5] The system ranges in brightness from a peak apparent visual magnitude of 12.4 down to 15.2,[3] 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.[2]
This system was identified as an ultraviolet excess object as part of the Palomar-Green (PG) survey by R. F. Green and associate in 1986. It was given the catalog identifier PG 0943+521, and was confirmed to be cataclysmic variable. In 1992, it was determined this is a dwarf nova that ranges in brightness from magnitude 12.3 down to 15.2. F. A. Ringwald in 1993 found a candidate orbital period of 0.1997 days based on radial velocity variation, but with some uncertainty.[7]
In 1995, T. Kato and C. Kunjaya confirmed this is a SU Ursae Majoris-type dwarf nova, and noted the unusual nature of this system, finding it has a long superoutburst lasting about 20 days and the supercycle (the time between superoutbursts) is very short at around 43 days.[8] Large amplitude superhumps were found to occur near the start of a superoutburst, with a brightness increase of around 0.35 magnitude.[9] The properties of the system suggest a high mass transfer rate and the white dwarf component is hotter than in other typical dwarf novae. During periods of quiescence, the accretion rate is 7.3×10−11 M☉·yr−1.[5]
References
[edit]- ↑ Zhao, Yinghe; Li, Zongyun; Wu, Xiaoan; Peng, Qiuhe; Zhang, Zhousheng; Li, Zili (April 2006), "Superhumps Behavior during Normal Outbursts in ER Ursae Majoris: Spectroscopy and Photometry", Publications of the Astronomical Society of Japan, 58 (2): 367–373, arXiv:astro-ph/0602181, Bibcode:2006PASJ...58..367Z, doi:10.1093/pasj/58.2.367, retrieved 25 October 2022.
- 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.
- 1 2 3 Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
- ↑ Thorstensen, J. R.; et al. (April 1997), "Orbital Periods for the Unusual Dwarf Novae ER Ursae Majoris and V1159 Orionis", Publications of the Astronomical Society of the Pacific, 109: 477–482, Bibcode:1997PASP..109..477T, doi:10.1086/133904, S2CID 121582607.
- 1 2 3 4 5 6 Guzman, Giannina; et al. (September 2019), "FUSE and IUE Spectroscopy of the Prototype Dwarf Nova ER Ursa Majoris During Quiescence", The Astronomical Journal, 158 (3): 99, arXiv:1907.06513, Bibcode:2019AJ....158...99G, doi:10.3847/1538-3881/ab322f, S2CID 196622682, 99.
- ↑ "ER UMa". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2022-10-15.
- ↑ Green, R. F.; et al. (June 1982), "Cataclysmic variable candidates from the Palomar Green Survey", Publications of the Astronomical Society of the Pacific, 94: 560–564, Bibcode:1982PASP...94..560G, doi:10.1086/131022, S2CID 120644760.
- ↑ Kato, Taichi; Kunjaya, Chatief (April 1995), "Discovery of a Peculiar SU UMa-Type Dwarf Nova ER Ursae Majoris", Publications of the Astronomical Society of Japan, 47: 163–168, Bibcode:1995PASJ...47..163K.
- ↑ Kato, Taichi; et al. (February 1996), "Large-Amplitude Superhumps in ER Ursae Majoris during the Earliest Stage of a Superoutburst", Publications of the Astronomical Society of Japan, 48: L5–L7, Bibcode:1996PASJ...48L...5K, doi:10.1093/pasj/48.1.L5.
Further reading
[edit]- Zemko, P.; et al. (March 2014), "Study of a long and short—term variability of ER Ursae Majoris", Contributions of the Astronomical Observatory Skalnaté Pleso, 43 (3): 319–324, Bibcode:2014CoSka..43..319Z.
- Zemko, Polina; et al. (June 2013), "Detection of Change in Supercycles in ER Ursae Majoris", Publications of the Astronomical Society of Japan, 65 (3): 8, arXiv:1212.5940, Bibcode:2013PASJ...65...54Z, doi:10.1093/pasj/65.3.54, 54.
- Ohshima, Tomohito; et al. (August 2012), "Discovery of Negative Superhumps during a Superoutburst of 2011 January in ER Ursae Majoris", Publications of the Astronomical Society of Japan, 64 (4): L3, arXiv:1207.2705, Bibcode:2012PASJ...64L...3O, doi:10.1093/pasj/64.4.L3.
- Kjurkchieva, D.; Marchev, D. (September 2010), "Large-Amplitude Modulations of the Cataclysmic Star ER UMa", Publications of the Astronomical Observatory of Belgrade, 90: 147–150, Bibcode:2010POBeo..90..147K.
- Kato, Taichi; et al. (April 2003), "Unusual Phase Reversal of Superhumps in ER Ursae Majoris", Publications of the Astronomical Society of Japan, 55 (2): L7–L10, arXiv:astro-ph/0211520, Bibcode:2003PASJ...55L...7K, doi:10.1093/pasj/55.2.L7.
- Gao, Weihong; et al. (December 1999), "Superhumps in a Peculiar SU Ursae Majoris-Type Dwarf Nova, ER Ursae Majoris", The Astrophysical Journal, 527 (1): L55–L59, arXiv:astro-ph/9910558, Bibcode:1999ApJ...527L..55G, doi:10.1086/312398, PMID 10566998, S2CID 16090638.
- Szkody, P.; et al. (1996), "IUE and Optical Spectra of RZ LMi and ER UMa Throughout their 19 and 43 Day Cycles", in Evans, A.; Wood, Janet H. (eds.), Cataclysmic variables and related objects. Proceedings of the 158th colloquium of the International Astronomical Union (IAU); held at Keele; United Kingdom; June 26-30; 1995, Astrophysics and Space Science Library, vol. 208, Dordrecht: Kluwer Academic Publishers, p. 55, Bibcode:1996ASSL..208...55S, doi:10.1007/978-94-009-0325-8_15, ISBN 978-94-010-6632-7, S2CID 197532794.
- Kato, Taichi; et al. (August 1995), "Photometric Detection of the Orbital Period in ER UMa", Information Bulletin on Variable Stars, 4233: 1, Bibcode:1995IBVS.4233....1K.
- Osaki, Yoji (April 1995), "A Model for a Peculiar SU Ursae Majoris-Type Dwarf Nova ER Ursae Majoris", Publications of the Astronomical Society of Japan, 47: L11–L14, Bibcode:1995PASJ...47L..11O.
- Robertson, J. W.; et al. (May 1995), "RZ Leonis Minoris, PG 0943+521, and V1159 Orionis: Three Cataclysmic Variables with Similar and Unusual Outburst Behavior", Publications of the Astronomical Society of the Pacific, 107: 443, Bibcode:1995PASP..107..443R, doi:10.1086/133572, S2CID 119609461.
