MULTIWAVELENGTH PHOTOMETRY AND HUBBLE SPACE TELESCOPE SPECTROSCOPY OF THE OLD NOVA V842 CENTAURUS
- Department of Astronomy and Astrophysics, Villanova University, 800 Lancaster Avenue, Villanova, PA 19085 (United States)
- Department of Astronomy, University of Washington, Seattle, WA 98195 (United States)
- Astrophysics, Cosmology and Gravity Centre, Department of Astronomy, University of Cape Town, Private Bag X3, Rondebosch 7701 (South Africa)
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794 (United States)
- AAVSO 49 Bay State Road, Cambridge, MA 02138 (United States)
- Department of Astronomy and Astrophysics, Villanova University, Villanova, PA 19085 (United States)
We present ground-based optical and near infrared photometric observations and Hubble Space Telescope (HST) COS spectroscopic observations of the old nova V842 Cen (Nova Cen 1986). Analysis of the optical light curves reveals a peak at 56.5 {+-} 0.3 s with an amplitude of 8.9 {+-} 4.2 mma, which is consistent with the rotation of a magnetic white dwarf primary in V842 Cen that was detected earlier by Woudt et al., and led to its classification as an intermediate polar. However, our UV lightcurve created from the COS time-tag spectra does not show this periodicity. Our synthetic spectral analysis of an HST COS spectrum rules out a hot white dwarf photosphere as the source of the FUV flux. The best-fitting model to the COS spectrum is a full optically thick accretion disk with no magnetic truncation, a low disk inclination angle, low accretion rate and a distance less than half the published distance that was determined on the basis of interstellar sodium D line strengths. Truncated accretion disks with truncation radii of 3 R{sub wd} and 5 R{sub wd} yielded unsatisfactory agreement with the COS data. The accretion rate is unexpectedly low for a classical nova only 24 yr after the explosion when the accretion rate is expected to be high and the white dwarf should still be very hot, especially if irradiation of the donor star took place. Our low accretion rate is consistent with those derived from X-ray and ground-based optical data.
- OSTI ID:
- 22121804
- Journal Information:
- Astrophysical Journal, Vol. 772, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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