DW Cancri
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cancer |
| Right ascension | 07h 58m 53.04s[1] |
| Declination | +16° 16′ 45.2″[1] |
| Apparent magnitude (V) | 11.36 - 16.3[2] |
| Characteristics | |
| Evolutionary stage | White dwarf + Red dwarf |
| Variable type | U Gem[2] |
| Astrometry | |
| Radial velocity (Rv) | 38.970486[1] km/s |
| Proper motion (μ) | RA: -25.973[1] mas/yr Dec.: -0.142[1] mas/yr |
| Parallax (π) | 4.8818±0.0395 mas[3] |
| Distance | 668 ± 5 ly (205 ± 2 pc) |
| Other designations | |
| DW Cnc, AAVSO 0753+16, TIC 19028616[1] | |
| Database references | |
| SIMBAD | data |
DW Cancri (DW Cnc) is a cataclysmic variable (CV) star system located in the constellation of Cancer.[1] It is classified as an intermediate polar (IP), a subtype of magnetic CV characterized by a white dwarf primary with a moderately strong magnetic field that channels accretion from a low-mass companion star.[4][5] The system exhibits behaviors typical of VY Scl-type variables, including prolonged low states and occasional brightenings.[6] DW Cnc has an orbital period of approximately 86 minutes, placing it below the period gap for CVs.[4][5]
Discovery
DW Cancri was identified as a potential CV during the Byurakan survey for blue galaxies and quasars, where it appeared as an emission-line object due to strong Balmer series lines in its spectrum.[4] Further spectroscopic confirmation established it as a CV, with initial studies noting its nova-like characteristics and lack of typical dwarf nova outbursts. The system's magnetic nature was inferred from periodic photometric and spectroscopic modulations consistent with an intermediate polar.[4]
Characteristics
DW Cnc is a close binary system consisting of a white dwarf primary and a low-mass main-sequence secondary, likely a red dwarf, from which material is accreted via Roche lobe overflow.[4][5] The white dwarf's magnetic field, estimated to be moderately strong, disrupts the inner accretion disk and funnels material to its magnetic poles, producing characteristic spin-period modulations.[4]
Variability
DW Cnc displays two distinct states: a high state at V ≈ 14.5–15 magnitude and prolonged low states ≈2 magnitudes fainter (V ≈ 16.5–17.5), characteristic of VY Scl stars where reduced mass transfer dims the system.[7][6] In low states, the accretion disk may be depleted, weakening periodic signals like the spin period.[5]
The first observed outburst occurred in 2007, brightening by ≈4 magnitudes to V ≈ 11.36 before fading ≈2.25 magnitudes in 27 hours.[8] More recent observations identified three short high-state outbursts lasting ≈1 day each, with a recurrence time of ≈60 days and amplitude ≈1 magnitude, potentially magnetically gated.[7] These events contrast with the typical quiescence of intermediate polars and suggest episodic mass transfer enhancements.[5]
Kilo-second quasi-periodic oscillations (QPOs) have been detected, with continuous signals over 61 days, interpreted as accretion instabilities or disk modes.[9]
References
- ^ a b c d e f g "DW Cancri". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2026-02-13.
- ^ a b Samus', N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports. 61 (1): 80. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085.
- ^ European Space Agency; Gaia collaboration (2020), Gaia EDR3, Centre de Donnees Strasbourg (CDS), doi:10.26093/CDS/VIZIER.1350, retrieved 2026-03-22
- ^ a b c d e f Warner, Brian (2004). "Rapid Oscillations in Cataclysmic Variables". Publications of the Astronomical Society of the Pacific. 116 (816): 115. arXiv:astro-ph/0312182. Bibcode:2004PASP..116..115W. doi:10.1086/381742.
- ^ a b c d e Ramírez, S. H.; Segura Montero, O.; Michel, R.; Echevarría, J. (2022). "New Photometry and Spectroscopy of DW Cancri". Revista Mexicana de Astronomia y Astrofisica. 58: 47. arXiv:2112.03433. Bibcode:2022RMxAA..58...47R. doi:10.22201/ia.01851101p.2022.58.01.04.
- ^ a b Rodríguez-Gil, P.; Gänsicke, B. T.; Araujo-Betancor, S.; Casares, J. (2004). "DW Cancri: A magnetic VY SCL star with an orbital period of 86 min". Monthly Notices of the Royal Astronomical Society. 349 (1): 367. arXiv:astro-ph/0312149. Bibcode:2004MNRAS.349..367R. doi:10.1111/j.1365-2966.2004.07512.x.
- ^ a b Duffy, C.; Ramsay, G.; Steeghs, D.; Kennedy, M. R.; West, R. G.; Wheatley, P. J.; Dhillon, V. S.; Ackley, K.; Dyer, M. J.; Galloway, D. K.; Gill, S.; Acton, J. S.; Burleigh, M. R.; Casewell, S. L.; Goad, M. R.; Henderson, B. A.; Tilbrook, R. H.; Strøm, P. A.; Anderson, D. R. (2022). "The return of the spin period in DW CNC and evidence of new high state outbursts". Monthly Notices of the Royal Astronomical Society. 510 (1): 1002. arXiv:2111.10416. Bibcode:2022MNRAS.510.1002D. doi:10.1093/mnras/stab3402.
- ^ Crawford, T.; Boyd, D.; Gualdoni, C.; Gomez, T.; MacDonald, W., II ; Oksanen, A. (2008). "Detection of the First Obeserved Outburst of DW Cancri". Journal of the American Association of Variable Star Observers (Jaavso). 36 (1): 60. Bibcode:2008JAVSO..36...60C.
- ^ Uemura, Makoto; Kato, Taichi; Ishioka, Ryoko; Novak, Rudolf; Pietz, Jochen (2002). "Kilo-Second Quasi-Periodic Oscillations in the Cataclysmic Variable DW Cancri". Publications of the Astronomical Society of Japan. 54 (2): 299. arXiv:astro-ph/0203247. Bibcode:2002PASJ...54..299U. doi:10.1093/pasj/54.2.299.