CV Watch List
Post date: 27-Mar-2009 17:01:51
Please report outbursts or unusual activity of these CVs as soon as possible.
An observing campaign is defined as a request for observations to achieve a specific goal, usually over a finite amount of time. Long-term monitoring campaigns for specific objects and research efforts will be listed here.
AAVSO CV Campaigns
The BAAVSS Long Term Polar Monitoring Programme has been set up to monitor over a period of years a selection of AM Her stars (see list below), which are in need of further investigation.
The objective is to observe on a nightly basis both visually and with CCD's, and to report any change in high/low state activity. The programme is supported by Dr Boris Gaensicke, Warwick University, whose article on Polars appeared in the September 2006 issue of the BAAVSS Circular (No. 129), and was the catalyst for this programme to be launched. You can read the article here.
A new picture of polar accretion is evolving
Image credit: S. Howell / P. Marenfeld/NOAO
The main aims of the programme are...
To monitor for outbursts or unusual behaviour either visually or with CCD's, in order to determine an outburst cycle, and with the help of CCD photometry, the orbital period.
To obtain high quality photometry during outburst.
To raise the profile of the objects on the programme in order that greater observational coverage will be obtained.
To provide Professional astronomers with much needed data on these stars.
At present there are 79 objects on the programme (see below). Most are Dwarf Novae, but several Novae have been included where more than one outburst has been detected, or is suspected of being recurrent from professional literature. Other interesting NL objects appear too!
Most cataclysmic variables (CVs) have been discovered either because of their variability, strong X-ray emission, or very blue colours. We have started a program to find CVs because of their peculiar emission line spectra, selecting candidates from the Hamburg Quasar Survey.
The motivation of this project has been to test whether this selection would unravel new types of CVs (which it did, e.g. the low accretion rate polars such as HS1023+3900), and we had the hope to find the many short-period CVs that CV evolution theory predicts.
Interestingly enough, most of the new CVs have no or very rare outbursts, but instead of numerous short-period systems, we found a large fraction of long-period CVs, some of them clear members of the SW Sex class, but in some cases it is very difficult to unambiguously identify the CV subtype. While some systems appear to be rather normal dwarf novae, such as the recently outbursting HS0417+7445, it it is very important for the majority of the systems to gather detailed long-term light curves of these systems to better understand their nature.