July 16, 2015: Roque Ruiz-Carmona (Ph.D. candidate, Institute of Mathematics, Astrophysics and Particle Physics, Radboud University Nijmegen, The Netherlands) has requested AAVSO assistance with his campaign to observe 17 cataclysmic variables (CVs) with the William Herschel Telescope (WHT) next week.
In order for WHT to observe each of the targets safely and to maximize the science value of the observations obtained, it is essential to know whether they are in outburst or quiescence. To this end, the PI has requested our observers to obtain an image of each of the targets so he may analyze them. For this campaign, it is not necessary for observers to determine and submit a magnitude estimate of each target, just to obtain an image and place it where the PI can access it.
Any filter may be used, and a raw or reduced image of each target may be submitted. Only one image per observer per target should be submitted. Please do not submit multiple images of any target.
Observers should post their images to a thread ("17 PTF CVs campaign") that has been created in the AAVSO Campaigns & Observation Reports forum, and include the date/time, filter, and exposure in the posting.
Timing is very important because the PI has to decide whether to exclude any target(s) 24 hours in advance of the WHT observations. Thus, the images must be taken and posted within a certain window.
The WHT observations will take place 2015 July 22-26 UT. The images must be taken between 21 July 20:00 UT and 22 July 15:00 UT. They must be posted to the thread not later than 22 July 19:00 UT.
The table of targets is given below (r values are Sloan magnitudes). Some of the targets are quite faint, and stacking of images may be necessary. The maximum size of an image file that can be uploaded to the Forum thread is 40 MB, so if any files are larger, please trim the image(s).
|PTF ID||Primary Name||RA (2000)||Dec (2000)||r_quiesc.||r_outb.||Type||Priority|
|PTFS1120ac||1RXS J203242.4+104937||20:32:42.44||+10:49:34.7||17.46||15.50||CV (X-ray)||Medium|
Observers should use a combination of AAVSO charts and charts supplied by the PI. Finder charts with sequences may be created using the AAVSO Variable Star Plotter (VSP). PDF images of PTF (Palomar Transient Factory) close-up finder charts containing the targets and offset stars chosen by the PI may be downloaded here. Please be sure that an image includes the offset stars, especially if you trim it so its size is less than 40MB.
Because the window for observation by AAVSO observers is relatively short and the target list is quite long, it is recommended that observers coordinate their observing plans so that all of the targets (both high and medium priority) are covered if at all possible. Please use the forum thread given above to post what targets you plan to observe; if you see that more difficult targets are not being covered and you can observe them, your doing so would be greatly appreciated.
Once all images have been posted to the campaign thread, observers are encouraged to reduce their images using the sequences available via VSP, and submit them to the AAVSO International Database using the primary names (not PTF names) as given in the table above. DO NOT USE magnitudes given in the PTF charts for data reduction.
This AAVSO Alert Notice was compiled by Elizabeth O. Waagen.
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