Abstract
KL Dra is a helium-accreting AM CVn binary system with an orbital period close to 25min. Approximately every 60d there is a 4-mag optical outburst lasting ∼10d. We present the most sensitive X-ray observations made of an AM CVn system during an outburst cycle. A series of eight observations were made using XMM-Newton which started shortly after the onset of an optical outburst. We find that X-rays are suppressed during the optical outburst. There is some evidence for a spectral evolution of the X-ray spectrum during the course of the outburst. A periodic modulation is seen in the ultraviolet data at three epochs - this is a signature of the binary orbital or the superhump period. The temperature of the X-ray-emitting plasma is cooler compared to dwarf novae, which may suggest that a wind is the origin of a significant fraction of the X-ray flux.
Original language | English |
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Pages (from-to) | 1486-1491 |
Number of pages | 6 |
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 425 |
Issue number | 2 |
DOIs | |
Publication status | Published - 11 Sept 2012 |
Externally published | Yes |
Keywords
- Accretion, accretion discs
- Binaries: general
- Novae, cataclysmic variables
- Stars: dwarf novae
- Stars: individual: KL Dra
- X-rays: stars