 A visual band light curve for CR Boötis, plotted from 2019 AAVSO data. [1] The data have been folded with the supercycle period found by Kato et al. [2] | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Boötes |
| Right ascension | 13h 48m 55.222s [3] |
| Declination | +07° 57′ 35.72″ [3] |
| Apparent magnitude (V) | 13.0 to 17.5 [4] |
| Characteristics | |
| Evolutionary stage | Double white dwarf [5] |
| Variable type | Dwarf nova(?) [4] |
| Astrometry | |
| Proper motion (μ) |
RA: –34.412
[3]
mas/
yr Dec.: 13.105 [3] mas/ yr |
| Parallax (π) | 2.8438 ± 0.0367 mas [3] |
| Distance | 1,150 ± 10
ly (352 ± 5 pc) |
| Details | |
| Primary | |
| Mass | 0.80 [6] M☉ |
| Radius | 0.012 [6] R☉ |
| Donor star | |
| Mass | 0.07 [6] M☉ |
| Radius | 0.0526 [6] R☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
CR Boötis is an interacting binary system in the northern constellation of Boötes, abbreviated CR Boo. It is one of the best-known AM Canum Venaticorum stars. [8] The system varies widely in brightness, ranging in apparent visual magnitude from 13.6 down to 17.5. [2] The distance to this system is approximately 1,150 light years from the Sun, based on parallax measurements. [3]
The variable luminosity of this object was discovered in 1983 by M. A. Wood and associates, with a light curve that is very similar to that of AM Canum Venaticorum. [9] It was found to have an ultraviolet excess by the Palomar-Green survey and assigned the identifier PG 1346+082 in 1986. [10] The system varies in both its photometric and spectroscopic properties, with a photometric quasi-period of 4–5 days. The optical spectrum displays only lines of helium. [9]
Rapid flickering suggests this is a close binary system undergoing mass transfer, while emission by neutral helium indicates there is a thick accretion disk orbiting a compact object. The lack of X-ray emission means this accreting object is a white dwarf, rather than something more massive. The lack of hydrogen in the spectrum demonstrates that the donor star is a helium white dwarf with a lower mass than the primary. [9] The pair have a brief orbital period of 24.522 minutes with a mass ratio of 0.101±0.004. [8] The orbital plane is inclined at an angle of about 30° to the line of sight from the Earth. [5]
This system displays two different states. The first is a lower state of quiescence that displays regular superoutbursts similar to ER Ursae Majoris on a roughly 46 day cycle. The second state is brighter with frequent outbursts. [8] The system becomes bluer during superoutbursts, with a higher temperature. [5]
References
- ^ "Download Data". aavso.org. AAVSO. Retrieved 26 March 2023.
- ^ a b Kato, Taichi; et al. (June 2000), "CR Boo: the 'helium ER UMa star' with a 46.3-d supercycle", Monthly Notices of the Royal Astronomical Society, 315 (1): 140–148, Bibcode: 2000MNRAS.315..140K, doi: 10.1046/j.1365-8711.2000.03440.x, S2CID 121203405.
- ^ a b c d e f 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.
- ^ a b 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.
- ^ a b c Boneva, Daniela; et al. (November 2022), "Recent observations of humps and superhumps and an estimation of outburst parameters of the AM CVn star CR Boo", Astrophysics and Space Science, 367 (11): 110, arXiv: 2212.07189, Bibcode: 2022Ap&SS.367..110B, doi: 10.1007/s10509-022-04149-z, S2CID 253631390, 110.
- ^ a b c d Boneva, Daniela; et al. (August 2021), "Mid-Cycle Observations of CR Boo and Estimation of the System's Parameters", Data, 5 (4): 113, arXiv: 2108.10421, doi: 10.3390/data5040113.
- ^ "CR Boo". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2023-03-06.
- ^ a b c Isogai, Keisuke; et al. (August 2016), "Superoutburst of CR Bootis: Estimation of mass ratio of a typical AM CVn star by stage A superhumps", Publications of the Astronomical Society of Japan, 68 (4): 64, arXiv: 1605.05408, Bibcode: 2016PASJ...68...64I, doi: 10.1093/pasj/psw063, 64.
- ^ a b c Wood, M. A.; et al. (February 1987), "The Exotic Helium Variable PG 1346+082", Astrophysical Journal, 313: 757, Bibcode: 1987ApJ...313..757W, doi: 10.1086/165014.
- ^ Green, R. F.; et al. (1986). "The Palomar-Green Catalog of Ultraviolet-Excess Stellar Objects". The Astrophysical Journal Supplement Series. 61: 305. Bibcode: 1986ApJS...61..305G. doi: 10.1086/191115.
Further reading
- Kato, Taichi; et al. (February 2023), "Genuine standstill in the AM CVn star CR Boo", arXiv: 2302.04454 [ astro-ph.SR
- Isogai, K.; et al. (2015), "Research on AM CVn stars: ASASSN-14ei and CR Boo", Proceedings of The Golden Age of Cataclysmic Variables and Related Objects - III (Golden2015). 7-12 September 2015. Palermo, Italy, p. 049, Bibcode: 2015gacv.workE..49I, doi: 10.22323/1.255.0049, 49.
- Honeycutt, R. Kent; et al. (February 2013), "Light Curve of CR Bootis 1990-2012 from the Indiana Long-Term Monitoring Program", Publications of the Astronomical Society of the Pacific, 125 (924): 126, Bibcode: 2013PASP..125..126H, doi: 10.1086/669542, S2CID 125036114.
- Kato, Taichi; et al. (June 2001), "The Second Supercycle of the Helium ER UMa Star, CR Boo", Information Bulletin on Variable Stars, 5120: 1, Bibcode: 2001IBVS.5120....1K.
- Patterson, Joseph.; et al. (October 1997), "Superhumps in Cataclysmic Binaries. XII. CR Bootis, a Helium Dwarf Nova", Publications of the Astronomical Society of the Pacific, 109: 1100–1113, Bibcode: 1997PASP..109.1100P, doi: 10.1086/133982, S2CID 122373469.
- Provencal, J. L.; et al. (May 1997), "Whole Earth Telescope Observations of the Helium Interacting Binary PG 1346+082 (CR Bootis)", The Astrophysical Journal, 480 (1): 383–394, Bibcode: 1997ApJ...480..383P, doi: 10.1086/303971, hdl: 10183/108834, S2CID 20591761.
- Wood, M. A.; et al. (1987), Cox, A. N.; Sparks, W. M.; Starrfield, S. G. (eds.), "PG 1346+082: An interacting binary white dwarf system", Stellar Pulsation: Proceedings of a Conference Held as a Memorial to John P. Cox at the Los Alamos National Laboratory Los Alamos, New Mexico, USA, August 11-15,1986, Lecture Notes in Physics, vol. 274, pp. 348–351, Bibcode: 1987LNP...274..348W, doi: 10.1007/3-540-17668-3_233, ISBN 978-3-540-17668-8.
- Wood, M. A.; et al. (September 1985), "The Exotic Helium Variable PG 1346+082", Bulletin of the American Astronomical Society, 17: 886, Bibcode: 1985BAAS...17..886W.
- Nather, R. E.; et al. (December 1984), Marsden, B. G. (ed.), "PG 1346+082", IAU Circular, 4021 (2): 2, Bibcode: 1984IAUC.4021....2N.
A visual band light curve for CR Boötis, plotted from 2019 AAVSO data. [1] The data have been folded with the supercycle period found by Kato et al. [2] | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Boötes |
| Right ascension | 13h 48m 55.222s [3] |
| Declination | +07° 57′ 35.72″ [3] |
| Apparent magnitude (V) | 13.0 to 17.5 [4] |
| Characteristics | |
| Evolutionary stage | Double white dwarf [5] |
| Variable type | Dwarf nova(?) [4] |
| Astrometry | |
| Proper motion (μ) |
RA: –34.412
[3]
mas/
yr Dec.: 13.105 [3] mas/ yr |
| Parallax (π) | 2.8438 ± 0.0367 mas [3] |
| Distance | 1,150 ± 10
ly (352 ± 5 pc) |
| Details | |
| Primary | |
| Mass | 0.80 [6] M☉ |
| Radius | 0.012 [6] R☉ |
| Donor star | |
| Mass | 0.07 [6] M☉ |
| Radius | 0.0526 [6] R☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
CR Boötis is an interacting binary system in the northern constellation of Boötes, abbreviated CR Boo. It is one of the best-known AM Canum Venaticorum stars. [8] The system varies widely in brightness, ranging in apparent visual magnitude from 13.6 down to 17.5. [2] The distance to this system is approximately 1,150 light years from the Sun, based on parallax measurements. [3]
The variable luminosity of this object was discovered in 1983 by M. A. Wood and associates, with a light curve that is very similar to that of AM Canum Venaticorum. [9] It was found to have an ultraviolet excess by the Palomar-Green survey and assigned the identifier PG 1346+082 in 1986. [10] The system varies in both its photometric and spectroscopic properties, with a photometric quasi-period of 4–5 days. The optical spectrum displays only lines of helium. [9]
Rapid flickering suggests this is a close binary system undergoing mass transfer, while emission by neutral helium indicates there is a thick accretion disk orbiting a compact object. The lack of X-ray emission means this accreting object is a white dwarf, rather than something more massive. The lack of hydrogen in the spectrum demonstrates that the donor star is a helium white dwarf with a lower mass than the primary. [9] The pair have a brief orbital period of 24.522 minutes with a mass ratio of 0.101±0.004. [8] The orbital plane is inclined at an angle of about 30° to the line of sight from the Earth. [5]
This system displays two different states. The first is a lower state of quiescence that displays regular superoutbursts similar to ER Ursae Majoris on a roughly 46 day cycle. The second state is brighter with frequent outbursts. [8] The system becomes bluer during superoutbursts, with a higher temperature. [5]
References
- ^ "Download Data". aavso.org. AAVSO. Retrieved 26 March 2023.
- ^ a b Kato, Taichi; et al. (June 2000), "CR Boo: the 'helium ER UMa star' with a 46.3-d supercycle", Monthly Notices of the Royal Astronomical Society, 315 (1): 140–148, Bibcode: 2000MNRAS.315..140K, doi: 10.1046/j.1365-8711.2000.03440.x, S2CID 121203405.
- ^ a b c d e f 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.
- ^ a b 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.
- ^ a b c Boneva, Daniela; et al. (November 2022), "Recent observations of humps and superhumps and an estimation of outburst parameters of the AM CVn star CR Boo", Astrophysics and Space Science, 367 (11): 110, arXiv: 2212.07189, Bibcode: 2022Ap&SS.367..110B, doi: 10.1007/s10509-022-04149-z, S2CID 253631390, 110.
- ^ a b c d Boneva, Daniela; et al. (August 2021), "Mid-Cycle Observations of CR Boo and Estimation of the System's Parameters", Data, 5 (4): 113, arXiv: 2108.10421, doi: 10.3390/data5040113.
- ^ "CR Boo". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2023-03-06.
- ^ a b c Isogai, Keisuke; et al. (August 2016), "Superoutburst of CR Bootis: Estimation of mass ratio of a typical AM CVn star by stage A superhumps", Publications of the Astronomical Society of Japan, 68 (4): 64, arXiv: 1605.05408, Bibcode: 2016PASJ...68...64I, doi: 10.1093/pasj/psw063, 64.
- ^ a b c Wood, M. A.; et al. (February 1987), "The Exotic Helium Variable PG 1346+082", Astrophysical Journal, 313: 757, Bibcode: 1987ApJ...313..757W, doi: 10.1086/165014.
- ^ Green, R. F.; et al. (1986). "The Palomar-Green Catalog of Ultraviolet-Excess Stellar Objects". The Astrophysical Journal Supplement Series. 61: 305. Bibcode: 1986ApJS...61..305G. doi: 10.1086/191115.
Further reading
- Kato, Taichi; et al. (February 2023), "Genuine standstill in the AM CVn star CR Boo", arXiv: 2302.04454 [ astro-ph.SR
- Isogai, K.; et al. (2015), "Research on AM CVn stars: ASASSN-14ei and CR Boo", Proceedings of The Golden Age of Cataclysmic Variables and Related Objects - III (Golden2015). 7-12 September 2015. Palermo, Italy, p. 049, Bibcode: 2015gacv.workE..49I, doi: 10.22323/1.255.0049, 49.
- Honeycutt, R. Kent; et al. (February 2013), "Light Curve of CR Bootis 1990-2012 from the Indiana Long-Term Monitoring Program", Publications of the Astronomical Society of the Pacific, 125 (924): 126, Bibcode: 2013PASP..125..126H, doi: 10.1086/669542, S2CID 125036114.
- Kato, Taichi; et al. (June 2001), "The Second Supercycle of the Helium ER UMa Star, CR Boo", Information Bulletin on Variable Stars, 5120: 1, Bibcode: 2001IBVS.5120....1K.
- Patterson, Joseph.; et al. (October 1997), "Superhumps in Cataclysmic Binaries. XII. CR Bootis, a Helium Dwarf Nova", Publications of the Astronomical Society of the Pacific, 109: 1100–1113, Bibcode: 1997PASP..109.1100P, doi: 10.1086/133982, S2CID 122373469.
- Provencal, J. L.; et al. (May 1997), "Whole Earth Telescope Observations of the Helium Interacting Binary PG 1346+082 (CR Bootis)", The Astrophysical Journal, 480 (1): 383–394, Bibcode: 1997ApJ...480..383P, doi: 10.1086/303971, hdl: 10183/108834, S2CID 20591761.
- Wood, M. A.; et al. (1987), Cox, A. N.; Sparks, W. M.; Starrfield, S. G. (eds.), "PG 1346+082: An interacting binary white dwarf system", Stellar Pulsation: Proceedings of a Conference Held as a Memorial to John P. Cox at the Los Alamos National Laboratory Los Alamos, New Mexico, USA, August 11-15,1986, Lecture Notes in Physics, vol. 274, pp. 348–351, Bibcode: 1987LNP...274..348W, doi: 10.1007/3-540-17668-3_233, ISBN 978-3-540-17668-8.
- Wood, M. A.; et al. (September 1985), "The Exotic Helium Variable PG 1346+082", Bulletin of the American Astronomical Society, 17: 886, Bibcode: 1985BAAS...17..886W.
- Nather, R. E.; et al. (December 1984), Marsden, B. G. (ed.), "PG 1346+082", IAU Circular, 4021 (2): 2, Bibcode: 1984IAUC.4021....2N.
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