ISSN 2309-5539 (online)
Published by The VS-COMPAS Project © 2011-2014
Hrodna, 230005, Belarus

Variable Stars Observer Bulletin is all about variable stars science. It's made by amateurs and for amateurs. Here simplified contemporary data about different aspects of variable stars research is published. The bulletin is scheduled for six issues per year.

July-August 2013 (#1)

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Contents

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NSVS 15314262 - A new ACV variable by Ivan Adamin

A new fairly bright ACV variable star has been discovered by Alexandr Ditkovsky recently. With the median nearly 10.42m, it is the sixth-brightest ACV variable in the constellation of Canis Major. Read more >>

Six new close binary systems with O'Connell effect by Ivan Adamin

As part of the VS-COMPAS research program, here are six new objects proposed for which the presence of O'Connell effect in the light curve is clearly noted. All of them are short-periodic close binaries of EW type, except one: NSVS 3878776 is an interesting Beta Lyrae-like system. Read more >>

Elements for two T Tauri variables in Taurus by Ivan Adamin

There are two T Tauri-alike variable sources were discovered in the constellation of Taurus by the VS-COMPAS team. Elements are refined. Read more >>

NSV 13636 Classification Revised by Ivan Adamin

Being initially referenced by C.Hoffmeister as S 10089 Cyg, a long-periodic suspect, the NSV 13636 was finally resolved to SRA variable with period of 168.5 days. Read more >>

HST Reveals Debris Disk Around T Pyxidis by Ivan Adamin

T Pyx is a recurrent nova, erupting every 12 to 50 years and ejecting material that has formed the disk around the bright star. Hubble Space Telescope photographed T Pyx's latest outburst in April 2011, giving a rare look at stellar eruption in details. Read more >>

Expanding the list of W Virginis variable stars by Ivan Adamin

As of August 2013, the VSX database contains 252 records of CWA variables with only 32 of them known in the Northern hemisphere. Here are two new CWA stars are presented, discovered by the VS-COMPAS team members: NSVS 13622006 and 2MASS J18144389+5531238. Read more >>

Bright and interesting Cepheids by Ivan Adamin

Cepheids are yellow supergiant pulsating variable stars, which are probably the best-known and important of all pulsating variables. Generally, Cepheids have large amplitudes, making it possible to find them even in distant galaxies. The reason Cepheids change their brightness is believed due to pulsations mechanizm. Read more >>

What are the R Coronae Borealis stars? by Ivan Adamin

The RCB stars are interesting and important as they represent a short-lived stage of stellar evolution and reveal some detail on dust formation processes. Thus, R Coronae Borealis and other RCB stars are quite unusual and worthy of much attention. Since the Pigott's first observation, only about 100 RCB variables have been discovered, making this class a very rare kind of variable stars. Read more >>

Six new RR Lyrae stars with Blazhko effect by Ivan Adamin

As part of VS-COMPAS data-mining program, here are six new pulsating RR Lyrae variables with the presence of the Blazhko effect listed. The research result on these objects is submitted to the VSX catalog for the first time by the VS-COMPAS team members. Photometric data from publicly available surveys (NSVS, CRTS, ASAS) was used a a source for light curves. Read more >>

The Blazhko Effect mystery by Ivan Adamin

The Blazhko effect is a long-term, irregular modulation of the amplitude and period that occurs in some RR Lyrae stars and related pulsating variables The physical origin of the effect remains unknown for over a century. Read more >>

Public Photometry Banks as a Source for Data Mining by Ivan Adamin

Photometric surveys are essential for variable stars science. Nowadays an individual may access publicly available photometry sources for a research instead of maintaining own one. Surveys usually cover a significant area of the sky with millions of light measurements. This provides some advantages and allows a "fast start" though an user is restricted to only a data gathered during a pre-defined period in the past. Read more >>

Want to contribute an article? Feel free to contact us at:
http://www.vs-compas.belastro.net/bulletin-contribute

or please simply drop an email to [ivan dot adamin at gmail dot com]