Light curves and images of 67P/Churyumov-Gerasimenko are presented for the 2002-2003 apparition based on amateur CCD monitoring using a standardised method to produce consistent photometry in Johnson-Kron-Cousins system. Multiaperture data shows a large outburst at perihelion during which dust production increased by a factor of 2 to give a peak

We present deep images in H alpha +[NII] and [OIII] lambda 5007 of the region around NGC 7027 obtained with the wide field camera (WFC) at the Isaac Newton Telescope (INT). We observe the complex structure of the interstellar medium where the planetary is projected and identify a large spherically symmetric structure around the planetary nebula. A

We report our analysis of the stability of pulsation periods in the DAV star (pulsating hydrogen atmosphere white dwarf) ZZ Ceti, also called R548. On the basis of observations that span 31 years, we conclude that the period 213.13 s observed in ZZ Ceti drifts at a rate dP/dt=1.2 Gyr, comparable to the theoretical cooling timescale for the star

We present Heinrich Hertz Telescope CO (3-2) observations of a sample of 10 early-type galaxies detected both in far-infrared (IRAS) and in CO (1-0). Six of the objects (i.e., 60% of the sample) were detected in the CO (3-2) transition. Comparison of the beam-matched CO (3-2)/CO (1-0) and CO (2-1)/CO (1-0) intensity ratios with simple large

The faint end of the differential galaxy number counts n(m) in the Hubble Deep Field-North (HDF-N) has been determined for the F450W, F606W, and F814W filters by means of surface brightness fluctuation measurements. This technique allows us to explore n(m) beyond the limiting magnitude of the HDF, providing new, stronger constraints on the faint

We describe a Fourier-based method of separating bars from spirals in near-infrared images. The method takes advantage of the fact that a bar is typically a feature with a relatively fixed position angle and uses the simple assumption that the relative Fourier amplitudes due to the bar decline with radius past a maximum in the same or a similar