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Two large amplitude slowly pulsating hot subdwarf stars
(Oxford University Press, 2011)
The discovery observations of two new slowly pulsating subdwarf B stars (V1093 Her stars),
BPS CS22890−74 and PB 7032, are presented. Both stars are highly multiperiodic, and have –
for V1093 Her stars – large amplitudes. ...
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 ...
JL 82: a slowly pulsating hot subdwarf star in a close binary system
(Oxford University Press, 2009)
JL 82 is a known binary, consisting of an sdB star and a companion which is not directly
observable in the optical. Photometric measurements reported in this paper show it to variable
with both the binary period (∼0.75 ...
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 ...
What can be deduced from open cluster metallicity measurements?
(Oxford University Press, 2007)
The dependence of [Fe/H] on galactocentric distance, distance from the galactic mid-plane
and age is studied. Both ordinary least-squares and non-parametric regression in the form of a
‘generalized additive model’ are ...
Further observations of Hipparcos red stars and standards for UBV(RI)C photometry
(Oxford University Press, 2007)
We present homogeneous and standardized UBV(RI)C JHK photometry for over 100 M stars
selected from an earlier paper on the basis of apparent photometric constancy. L photometry
has been obtained for stars brighter than ...
Confidence intervals for the correlation between the gamma-ray burst peak energy and the associated supernova peak brightness
(Oxford University Press, 2009)
A strong correlation between the gamma-ray burster peak energy and the peak luminosity
of the associated supernova was discovered by Li for four GRBs. Despite the fact that the
formal significance level of the correlation ...
The detailed forms of the LMC Cepheid PL and PLC relations
(Oxford University Press, 2007)
Possible deviations from linearity of the Large Magellanic Cloud Cepheid period–luminosity
(PL) and period–luminosity–colour (PLC) relations are investigated. Two data sets are studied,
respectively from the Optical ...
The Nyquist frequency for time series with slight deviations from regular spacing
(Oxford University Press, 2009)
The paper is based on the notion that the Nyquist frequency νN is a symmetry point of the
periodogram of a time series: the power spectrum at frequencies above νN is a mirror image
of that below νN. Koen showed that the ...
HE 0230−4323 revisited: a new rapidly pulsating sdB star
(Oxford University Press, 2010)
HE 0230−4323 is a hot sdB star in a binary system. An earlier work demonstrated that the
light curve of the system shows a strong (∼4 per cent) reflection effect and also appears to
exhibit photometric variations of the ...