Section: PZ: main journal
The Recent Period Evolution of the RRc stars HY Com, RU Psc and AP Ser
The first overtone RR Lyrae stars HY Com, RU Psc and AP Ser have shown frequent sudden period changes in recent years, as calculated from NSVS and ASAS-3 data.
We present the discovery, photographic and V-band CCD observation of a new High Amplitude Delta Scuti star USNO-A2.0 0975-09853705.
The details for a serendipitously discovered R Coronae Borealis (RCB) variable are given.
New GCVS Versions for Three Southern Constellations
We are currently working on a version of the General Catalogue of Variable Stars (GCVS) revised taking into account the new data accumulated since the 4th GCVS edition. A draft new version will be released for each constellation as soon as the work for the constellation is finished. It will contain all stars of the 4th GCVS edition plus a complete catalogue of the stars added to the GCVS in the Name Lists of Variable Stars Nos. 67 - 78. Now we are ready for the first release, containing more than 1300 variable stars in the constellations of Antlia, Ara, and Telescopium. When preparing the release, we actively used modern data-mining possibilities to improve variability types and light elements. This paper introduces the first release of the new GCVS version and presents new results (types, light elements), based mainly on data mining, for 213 stars.
CCD VRI photometry is presented for SN 2002hh from 14 days after the outburst till day 347. SN 2002hh appears to be a normal IIP supernova regarding both luminosity and the shape of the light curve, which is similar to SN 1999gi.
Archival Photographic Light Curves of the Red Semiregular Star CPD -80 966 [1964 - 1976], and Modern CCD Multicolor Photometry
We used digitised scans of plates from the Bamberg Observatory Southern Photographic Patrol Survey to study the variation of the recently discovered semiregular variable star CPD -80 966 from 1964 to 1976. We present evidence to show that the star was varying during the course of the Bamberg survey, but was apparently overlooked at the time. We also present multicolour CCD photometry of CPD -80 966 from 2006 July to 2007 March.
Of the 379 candidate variables listed by F.E. Ross during 1925 - 1931, 97 appear in the NSV catalogue, and 51 of these were recorded on a single night. Ross recognized that some of the single-nighters were likely to be minor planets, and a few years ago J.R. Bedient identified six such cases. The present author has identified nine further Ross objects as long-known minor planets.
Variable Stars in NSVS Database I. 86 New Variables in Andromeda
A search for light curves with variability in the NSVS data was carried out in a 46 square-degree area in Andromeda. The field contains 51955 light curves. We found 136 variables, 86 of them were not known previously. Extrapolating the density of the variables in the field to the whole NSVS, the total number of variables in the survey is estimated to be 52000 - 61000.
CCD B & V Photometry of the Young, Active, Late-type Star PZ Telescopii
We present new CCD B and V photometry, obtained at the Brightwater Observatory in June and July 2006, of PZ Telescopii (HD 174429), a young, rapidly rotating late-type star with an active chromosphere. The CCD data were collected with a short focal-length telescope, giving a field of view near 0.80 x 0.55 deg, so target and comparison stars could be observed simultaneously. A periodogram analysis of the PZ Tel data returned a value of 0.94 d, consistent with earlier photometry. We found the amplitude of variation was ~0.06 mag in B and V, with evidence for a small colour variation of between 0.01 and 0.02 mag, the star being redder when fainter. From a comparison with previously published photometry we find that the amplitude of V-light variation is amongst the smallest ever observed. There is an indication that there was a maximum in the long-term brightness level near V=8.28 around the year 2000, with the current data being several hundredths of a magnitude fainter.
We present the results of our long-term homogeneous spectroscopy of T~Tau, the prototype T~Tauri star. We demonstrate that the star's absorption spectrum varies in time and is weakly correlated with variations of brightness and emission spectrum. With increasing intensities of emission lines, the veiling of the photospheric absorption decreases. It is suggested that the absorption-spectrum variations are due to variable additional emission superimposed on the photospheric spectrum and that the amount of veiling is inversely correlated with the emission-line strength in the spectrum of the star.