Browsing Researchers in Statistics and Population Studies by Issue Date
Now showing items 41-55 of 55
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More on the nature of the variable star UNSW-V-760
(Oxford University Press, 2012)The results of two multicolour time-series photometric observing runs, separated by about two months, are presented. The same periodicities previously detected in photometry of UNSWV- 760 are still present, albeit at ... -
Detection of an increasing orbital period in the subdwarf B eclipsing system NSVS 14256825
(Oxford University Press, 2012)New timings of eclipses made in 2010 and 2011 are presented for the hot subdwarf B (sdB) eclipsing binary NSVS 14256825. Composed of an sdB star and a much cooler companion, with a period near 0.1104 days, this system ... -
An extensive search for rapid optical variability in ultracool dwarfs
(Oxford University Press, 2013)In this paper, a summary of optical time-series photometry of 125 ultracool dwarfs is given. The observing strategy was to monitor each object continuously for 2–3 h in order to ascertain whether itwas rapidly variable. ... -
Time series models of three sets of RXTE Observations of 4U 1543-47
(Oxford University Press, 2013)The X-ray nova 4U 1543−47 was in a different physical state (low/hard, high/soft, and very high) during the acquisition of each of the three time series analyzed in this paper. Standard time series models of the ... -
Multicolour time series photometry of three periodic ultracool dwarfs
(Oxford University Press, 2013)Photometry in I, or contemporaneously in I and R, of the known variable ultracool dwarfs Kelu-1 and 2MASS J11553952−3727350 is presented. The nature of the variability of Kelu-1 appears to evolve on time-scales of a day ... -
Linking multi-epoch CCD photometry of partially overlapping fields
(Oxford University Press, 2013)A common problem in CCD photometry is to combine measurements obtained at different epochs. This is especially challenging if the fields only overlap partially, and are sparse, so that not all calibrating stars are ... -
An O−C (and light travel time) method suitable for application to large photometric databases
(Oxford University Press, 2014)The standard method of studying period changes in variable stars is to study the timing residuals or O−C values of light-curve maxima or minima. The advent of photometric surveys for variability, covering large parts of ... -
Multicolour time series photometry of the variable star 1SWASP J234401.81−212229.1
(Oxford University Press, 2014)1SWASP J234401.81-212229.1 may be one of a handful of contact binaries comprising two Mdwarfs. Modelling of the available observations is complicated by the fact that the radiation of the eclipsing system is dominated ... -
A search for p-mode pulsations in white dwarf stars using the Berkeley Visible Imaging Tube detector
(Oxford University Press, 2014)We present high-speed photometry (resolution 0.1 s) obtained during the commissioning of the Berkely Visible Imaging Tube system on the Southern African Large Telescope (SALT). The observations were an attempt to search ... -
A detection threshold in the amplitude spectra calculated from Kepler data obtained during K2 mission.
(Oxford University Press, 2015)We present our analysis of simulated data in order to derive a detection threshold which can be used in the pre-whitening process of amplitude spectra. In case of ground-based data of pulsating stars, this threshold is ... -
The analysis of indexed astronomical time series – XI. The statistics of oversampled white noise periodograms
(Oxford University Press, 2015)The distribution of the maxima of periodograms is considered in the case where the time series is made up of regularly sampled, uncorrelated Gaussians. It is pointed out that if there is no oversampling, then for large ... -
Multicolour time series photometry of four short-period weak-lined T Tauri stars
(Oxford University Press, 2015)The paper describes continuous photometric monitoring of four pre-main-sequence stars, probable members of young stellar associations. Measurements, covering at least four nights per star, were obtained by cycling through ... -
Multicolour time series photometry of the T Tauri star CVSO 30
(Oxford University Press, 2015)Five consecutive runs of at least five hours, and two shorter runs, of V(RI)C time series photometry of CVSO 30 are presented. No evidence could be seen for planetary transits, previously claimed in the literature for ... -
The analysis of indexed astronomical time series – XII. The statistics of oversampled Fourier spectra of noise plus a single sinusoid
(Oxford University Press, 2015)With few exceptions, theoretical studies of periodogram properties focus on pure noise time series. This paper considers the case in which the time series consists of noise together with a single sinusoid, observed at ... -
Modelling the rotation period distribution of M dwarfs in the Kepler field
(Springer Verlag, 2018)McQuillan et al. (Mon. Not. R. Astron. Soc.432:1203, 2013) presented 1570 periods P of M dwarf stars in the field of view of the Kepler telescope. It is expected that most of these reflect rotation periods, due to starspots. ...