We present the analysis of high-speed photometric observations of FSAur taken with the 4.2-m William Herschel Telescope and the high-speed camera ULTRACAM in late 2003. These observations were intended to determine whether there was any evidence of photometric variability with a period in the range 50–100 seconds. The discovery of such variations would help to explain existence, in FS Aur, of t...

UltraCamXp is the new flagship camera product which introduced in 2008 at the ISPRS Conference and Exhibition in Beijing by Vexcel Imaging (a Microsoft Company). This paper will give a technical overview about the advantages and concept of the camera. The focus is set on a large scale project which was carried out in late 2008 near Graz, Austria. Radiometric and geometric aspects of this flight...

V407 Vul (RXJ1914.4+2456) and HM Cnc (RXJ0806.3+1527) are X-ray emitting stars with X-ray light curves that are 100% modulated on periods of 569 and 321 seconds respectively. These periods are thought possibly to represent the orbital periods of close pairs of white dwarfs. In this paper we present optical light curves taken with the highspeed CCD camera ULTRACAM on the 4.2m WHT in May 2003 and...

High time resolution observations of a white–light flare on the active star EQ PegB show evidence of intensity variations with a period of ≈10 s. The period drifts to longer values during the decay phase of the flare. If the oscillation is interpreted as an impulsively–excited, standing–acoustic wave in a flare loop, the period implies a loop length of ≈1.7 Mm and ≈3.4 Mm for the case of the fu...

We present high-speed, three-colour photometry of the eclipsing cataclysmic variable SDSS J170213.26+322954.1 (hereafter SDSS J1702+3229). This system has an orbital period of 2.4 hours, placing it within the “period gap” for cataclysmic variables. We determine the system parameters via a parameterized model of the eclipse fitted to the observed light curve by χ minimization. We obtain a mass r...

AR Scorpii (AR Sco) is the only radio-pulsing white dwarf known to date. It shows a broad-band spectrum extending from radio X-rays whose luminosity cannot be explained by thermal emission system components alone, and instead through synchrotron powered spin-down of dwarf. We analysed NTT/ULTRACAM, TNT/ULTRASPEC, GTC/HiPERCAM high-speed photometric data for Sco spanning almost seven years obtai...

We report on a multi-epoch campaign of rapid optical/X-ray timing observations the superbright 2018 outburst MAXI J1820+070, black hole low-mass X-ray binary system. The spanned 80 days in initial hard-state, and were taken with NTT/ULTRACAM GTC/HiPERCAM optical (ugriz filters at time resolutions 8--300 Hz) ISS/NICER X-rays. find (i) growing anti-correlation between lightcurves, (ii) steady, po...

ABSTRACT We present a rapid timing analysis of optical (HiPERCAM and ULTRACAM) X-ray (NICER) observations the transient Swift J1858.6−0814 during 2018 2019. The light curves show relatively slow, large amplitude (∼1 mag in gs) ‘blue’ flares (i.e. stronger at shorter wavelengths) on time-scales ∼minutes as well fast, small (∼0.1 ‘red’ longer ∼seconds. are consistent with reprocessing optically t...