We present new B, V and I CCD time-series photometry for 177 variable stars in a 13 × 13arcmin2 field centred on the globular cluster M54 (lying at the centre...
The population, magnitudes, and sizes of Jupiter family comets
We analyze the sample of measured nuclear magnitudes of the observed Jupiter family (JF) comets (taken as those with orbital periods P 20 years and Tisserand...
The Possible Ascent of a Closed Magnetic System through the Photosphere
We present a comprehensive interpretation of the evolution of a small magnetic region observed during its entire disk passage. The vector magnetic field...
The possible connection between ionization in the atmosphere by cosmic rays and low level clouds
Recent analysis of monthly mean cloud data from the International Satellite Cloud Climatology Project uncovered a strong correlation between low cloud and the...
The possible origin of facular brightness in the solar atmosphere
This paper studies the dependence of the Ca ii H line core brightness on the strength and inclination of the photospheric magnetic field, and on the parameters...
The post-common envelope central stars of the planetary nebulae Henize 2-155 and Henize 2-161
We present a study of Hen 2-155 and Hen 2-161, two planetary nebulae which bear striking morphological similarities to other planetary nebulae known to host...
The post-common-envelope binary central star of the planetary nebula ETHOS 1
We present a detailed study of the binary central star of the planetary nebula ETHOS 1 (PN G068.1+11.0). Simultaneous modelling of light and radial velocity...
The post-common-envelope binary central star of the planetary nebula Ou 5: a doubly eclipsing post-red-giant-branch system
We present a detailed study of the stellar and orbital parameters of the post-common envelope binary central star of the planetary nebula Ou 5. Low-resolution...
The post-common-envelope binary central star of the planetary nebula PN G283.7-05.1. A possible post-red-giant-branch planetary nebula central star
We present the discovery and characterisation of the post-common-envelope central star system in the planetary nebula PN G283.7-05.1. Deep images taken as part...