The Open UniversitySkip to content
 

The nature of TW Pictoris

Norton, A. J.; Beardmore, A. P.; Retter, A. and Buckley, D. A. H. (2000). The nature of TW Pictoris. Monthly Notices of the Royal Astronomical Society, 312(2) pp. 362–370.

DOI (Digital Object Identifier) Link: http://dx.doi.org/10.1046/j.1365-8711.2000.03216.x
Google Scholar: Look up in Google Scholar

Abstract

The results of X-ray and optical observations of the candidate intermediate polar TW Pic are presented in an attempt to understand its nature. We find no sign of the previously proposed ∼2 h white-dwarf spin period and ∼6 h orbital period of TW Pic in its X-ray light curve. There is therefore no convincing evidence in support of its previous classification. The lack of X-ray pulsation could be the result of a low inclination angle, but in that case there would be no reason why an optical pulsation should have been seen previously. Negative results from polarimetry also preclude TW Pic from being a polar. One possibility may be that the shorter of the two periods is in fact the orbital period, whilst the longer one is a harmonic of a disc precession period. Alternatively, both the high accretion rate and period structure of TW Pic indicate that it may be a system that displays persistent negative superhumps. In this case the true orbital period of the binary may be around 6.36 h and the shorter of the two previously identified periods, 1.996 h, represents the (shifted) second harmonic of a negative superhump period of 6.06 h. Under this interpretation, it would be the longest period system to display such a phenomenon. Finally there is also evidence that TW Pic may be a VY Scl star, in which case it would be the longest period member of that subclass too.

Item Type: Journal Article
Copyright Holders: 2000 Royal Astronomical Society, Monthly Notices of the Royal Astronomical Society
ISSN: 1365-2966
Keywords: stars: individual; TW Pic - novae; cataclysmic variables - X-rays: stars
Academic Unit/Department: Science > Physical Sciences
Interdisciplinary Research Centre: Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)
Item ID: 24764
Depositing User: Andrew Norton
Date Deposited: 19 Nov 2010 22:41
Last Modified: 11 Jul 2013 15:25
URI: http://oro.open.ac.uk/id/eprint/24764
Share this page:

Actions (login may be required)

View Item
Report issue / request change

Policies | Disclaimer

© The Open University   + 44 (0)870 333 4340   general-enquiries@open.ac.uk