8 papers · 1 filter
ULTRACAM observations of two accreting white dwarf pulsators
C. M. Copperwheat, T. R. Marsh, V. S. Dhillon +6
In this paper we present high time-resolution observations of GW Librae and SDSS J161033.64-010223.3 -- two cataclysmic variables which have shown periodic variations attributed to…
Multiwavelength spectral and high time resolution observations of SWIFT J1753.5-0127: new activity?
M. Durant, P. Gandhi, T. Shahbaz +2
We have conducted an extensive observational campaign of SWIFT J1753.5-0127 during June 2007 after its bright outburst episode in 2005. We have performed multi-band optical photome…
Optical variability of the ultracool dwarf TVLM 513-46546: evidence for inhomogeneous dust clouds
S. P. Littlefair, V. S. Dhillon, T. R. Marsh +3
We present multi-colour photometry of the M8.5V ultracool dwarf "pulsar" TVLM 513-46546 (hereafter TVLM 513) obtained with the triple-beam photometer ULTRACAM. Data were obtained s…
Rapid optical and X-ray timing observations of GX 339-4: flux correlations at the onset of a low/hard state
P. Gandhi, K. Makishima, M. Durant +6
We present the discovery of optical/X-ray flux correlations on rapid timescales in the low/hard state of the Galactic black hole GX 339-4. The source had recently emerged from outb…
GD 552: a cataclysmic variable with a brown dwarf companion?
E. Unda-Sanzana, T. R. Marsh, B. T. Gansicke +7
GD 552 is a high proper motion star with the strong, double-peaked emission lines characteristic of the dwarf nova class of cataclysmic variable star, and yet no outburst has been…
SWIFT J1753.5-0127: a surprising optical/X-ray cross-correlation function
Martin Durant, Poshak Gandhi, Tariq Shahbaz +4
We have conducted optical and X-ray simultaneous observations of SWIFT J1753.5-0127 with RXTE and ULTRACAM, while the system persisted in its relatively bright low/hard state. In t…