Journal of Astronomy and Space Sciences

The Korean Space Science Society (한국우주과학회)
권호 표지
DOI QR코드

DOI QR Code

Long-Term Variation of the Spin Period of a Magnetic Cataclysmic Variable, MU Camelopardalis

  • Yun, A-Mi (University Observatory, Chungbuk National University) ;
  • Kim, Yong-Gi (University Observatory, Chungbuk National University) ;
  • Choi, Chul-Sung (Korea Astronomy and Space Science Institute)
  • Received : 2010.12.20
  • Accepted : 2011.02.11
  • Published : 2011.03.15
Download PDF
⟨ Previous Next ⟩

Abstract

Results of an analysis of 11 nights of R-filter CCD photometry data of an intermediate polar MU Camelopardalis (MU Cam) obtained at the Korean 1.0 m telescope at Mt. Lemmon are reported. After checking the spin period with our data, $P_{spin}=0.^d01373801(59)$, we compiled the reported data of maxima timing and an O-C diagram analysis has been carried out to understand the spin period variation. A significant spin period variation was detected, and fitting the O-C points to a cubic parabola led to an ephemeris of $BJD_{max}=2453682.4178(94)+0.0137380(13)E-2.07(55){\times}10^{-11}E^2+2.28(52){\times}10^{-15}E^3$. The torque experienced by the magnetic compact star accreting in a disk is estimated as ${\tau}{\approx}1.815{\times}10^{35}gcm^2/s^2$ in a simple approximation in order to show how important monitoring the period variation is. Thus we conclude that monitoring the long-term spin period variation will help to understand the physical condition of magnetic compact stars.

Keywords

References

  1. Araujo-Betancor S, Gansicke BT, Hagen H-J, Rodriguez-Gil P, Engels D, 1RXS J062518.2+733433: a new intermediate polar, A&A, 406, 213-219 (2003). doi: 10.1051/0004-6361:20030787
  2. Andronov IL, Antoniuk KA, Augusto P, Baklanov AV, Chinarova LL, et al., Inter-longitude astronomy project: some results and perspectives, A&AT, 22, 793-798 (2003). doi: 10.1080/1055679031000124501
  3. Andronov IL, Baklanov AV, Monitoring of cataclysmic variables at Kolonica Observatory, Astron Sch Rep, 5, 264-272 (2004).
  4. Andronov IL, Ostrova NI, Burwitz V, O-C analysis of FO Aqr, King of Intermediate Polars, in Proceedings of Astronomical Society of Pacific Conference Series, vol. 335, The light-time effect in astrophysics, ed. Sterken C (Astronomical Society of the Pacific, San Francisco, CA, 2005), 229.
  5. Ghosh P, Lamb FK, Accretion by rotating magnetic neutron stars. III - Accretion torques and period changes in pulsating X-ray sources, ApJ, 234, 296-316 (1979). doi: 10.1086/157498
  6. Hellier C, Cataclysmic variable stars: how and why they vary (Springer Verlag, Berlin, 2001).
  7. Kazarovets EV, Samus NN, Durlevich OV, Kireeva NN, Pastukhova EN, The 78th name-list of variable stars, IBVS, 5721, 1 (2006).
  8. Kim YG, Andronov IL, Jeon YB, CCD photometry using multiple comparison stars, JASS, 21, 191-200 (2004). doi: 10.5140/JASS.2004.21.3.191
  9. Kim YG, Andronov IL, Park SS, Chinarova LL, Baklanov AV, et al., Two-color VR CCD photometry of the intermediate polar 1RXS J062518.2+733433, JASS, 22, 197-210 (2005a). doi: 10.5140/JASS.2005.22.3.197
  10. Kim Y, Androniv IL, Park SS, Jeon Y-B, Orbital and spin variability of the intermediate polar BG CMi, A&A, 441, 663-674 (2005b). doi: 10.1051/0004-6361:20052995
  11. King AR, Frank J, Raine DJ, Accretion power in astrophysics, 3rd ed. (Cambridge University Press, Cambridge, 2002).
  12. Kozhevnikov VP, Zakharova PE, Nikiforova TP, Photometry of the intermediate polar 1RXS J062518.2+733433: characteristics of its periodic brightness variations, ARep, 50, 902-914 (2006). doi: 10.1134/S1063772906110047
  13. Lenz P, Breger M, Period04 user guide, CoAst, 146, 53-136 (2005). doi: 10.1553/cia146s53
  14. Massey P, Davis LE, A user’s guide to Stellar CCD photometry with IRAF (1992).
  15. Patterson J, The DQ Herculis stars, PASP, 106, 209-238 (1994). doi: 10.1086/133375
  16. Staude A, Schwope AD, Krumpe M, Hambaryan V, Schwarz R, 1RXS J062518.2+733433: a bright, soft intermediate polar, A&A, 406, 253-257 (2003). doi: 10.1051/0004-6361:20030705
  17. Staude A, Schwope AD, Schwarz R, Vogel J, Krumpe M, et al., The changing accretion states of the intermediate polar MU Camelopardalis, A&A, 486, 899-909 (2008). doi: 10.1051/0004-6361:20067013
  18. Warner B, Cataclysmic variable stars (Cambridge University Press, Cambridge, 1995)
  19. Warner B, Multiple optical orbital sidebands in intermediate polars, MNRAS, 219, 347-356 (1986). https://doi.org/10.1093/mnras/219.2.347
  20. Wei JY, Xu DW, Dong XY, Hu JY, An AGN sample with high X-ray-to-optical flux ratio from RASS. I. The optical identification, A&AS, 139, 575-599 (1999). doi: 10.1051/aas:1999514

Cited by

  1. Extensive photometry of the intermediate polar MU Cam: detection of a spin period change vol.361, pp.8, 2016, https://doi.org/10.1007/s10509-016-2859-0