Special Notice #416: Extension to 20 CVs campaign

May 25, 2016: Roque Ruiz-Carmona, the principal investigator on the observing campaign on 20 CVs that was announced in AAVSO Alert Notice 543, reports that the campaign has been revised due to telescope issues. He writes:

"I have just been notified that the there are technical issues with the alignment of the optics of William Herschel Telescope, and the instrument cannot be mounted until Friday 27. That means that my observing run will start on Friday rather than tonight. Moreover, the photometric camera will not be available, and I won't be able to check the state of the systems to pick the ones in which outbursts have just started.

"For this reason, *it will be very timely if we could continue with the monitoring three more nights.* So far, all systems observed are in quiescence. If any of them is found in outbursts in the following nights, it means that the outburst has started recently, and those systems are exactly what I aim to study. The images before the run starts will inform about systems in outburst, and I will study those systems. The images taken on the night of May 27 will provide additional information about the evolution of the outburst, or may identify new outbursts in case all targets remain in quiescence up to that point. New outbursts detected on the night of May 27 may change the targets I will study.

"One image of every target should be obtained:

 - between 25 May 17:00UT and 26 May 17:00 UT, posted no later than 27 May 18:00 UT
 - between 26 May 17:00UT and 27 May 17:00 UT, posted no later than 27 May 18:00 UT
 - between 27 May 17:00UT and 28 May 17:00 UT, posted no later than 28 May 18:00 UT

******On May 27, if you identify an outburst, please report it immediately in the forum (you can post the image later).******

"I hope this is clear enough; but if you have questions, don't hesitate contacting me [via the forum]."

The list of targets and a link to the finder charts to be used are given in Alert Notice 543.

The forum thread for this campaign - the place you should post your images and ask any questions - is:


Thank you very much for your continued imaging of these targets. Your assistance is essential to making the best use of the time the PI has on the William Herschel Telescope.

This AAVSO Special Notice was compiled by Elizabeth O. Waagen.


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