Astronomy: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 Equinox J2000.0]] (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[2] mas/yr Dec.: −6.209[2] mas/yr |
Parallax (π) | 2.8039 ± 0.0205[2] mas |
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 | |
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
- ↑ 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, doi:10.1093/pasj/58.2.367, Bibcode: 2006PASJ...58..367Z, https://academic.oup.com/pasj/article/58/2/367/1515863, retrieved 25 October 2022.
- ↑ 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 3.2 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.
- ↑ 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, doi:10.1086/133904, Bibcode: 1997PASP..109..477T.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 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, doi:10.3847/1538-3881/ab322f, 99, Bibcode: 2019AJ....158...99G.
- ↑ "ER UMa". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=ER+UMa.
- ↑ 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, doi:10.1086/131022, Bibcode: 1982PASP...94..560G.
- ↑ 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, doi:10.1093/pasj/48.1.L5, Bibcode: 1996PASJ...48L...5K.
Further reading
- 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, doi:10.1093/pasj/65.3.54, 54, Bibcode: 2013PASJ...65...54Z.
- 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, doi:10.1093/pasj/64.4.L3, Bibcode: 2012PASJ...64L...3O.
- 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, doi:10.1093/pasj/55.2.L7, Bibcode: 2003PASJ...55L...7K.
- 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, doi:10.1086/312398, PMID 10566998, Bibcode: 1999ApJ...527L..55G.
- Szkody, P. et al. (1996), Evans, A.; Wood, Janet H., eds., "IUE and Optical Spectra of RZ LMi and ER UMa Throughout their 19 and 43 Day Cycles", 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 (Dordrecht: Kluwer Academic Publishers) 208: p. 55, doi:10.1007/978-94-009-0325-8_15, ISBN 978-94-010-6632-7, Bibcode: 1996ASSL..208...55S.
- 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, doi:10.1086/133572, Bibcode: 1995PASP..107..443R.
![]() | Original source: https://en.wikipedia.org/wiki/ER Ursae Majoris.
Read more |