(vsnet-alert 455, Gary Poyner)
Outburst of DM Lyr (needs confirmation), which is monitored as part of the TA/BAAVSS Recurrent Objects Programme.
Jly 05.9771 UT mv=<14.8 Poyner 40cm 07.0431 14.5 " 07.0611 14.4 " 07.0819 14.3 "
My records show that the last outburst occurred on November 20 1995, when Jochen Pietz observed it at mag. 14.2
Has any recent photometry been done on comparison stars for DM Lyr?
Outburst CCD image
1996 July 12, 25-cm SCT + ST-7 unfiltered, 60s exposure (by T. Kato and D. Nogami)
(vsnet-alert 409, D. Nogami)
We, Ouda Team, observed DM Lyr last night (7/16) and detected superhumps with an amplitude of about 0.1 mag. DM Lyr has, thus, been proved to be a new member of SU UMa stars! Our preliminary period analysis gives 0.066 (+-0.002) day as the best estimated superhump period. The future behavior of this variable also deserves attention.
We thank all observers who have posted their observations of DM Lyr to VSNET!!!
At 16:48 17/07/96 +0100, Gary Poyner wrote: >Lyr DM 16.967 14.6 Could this have possibly been a > superoutburst?
Comparing the present outburst with photometric summaries of previous ones, one indeed gets the impression that the current outburst must be a superoutburst (hence establishing DM Lyr as a member of the UGSU dwarf novae). I have started a time series CCD photometry on DM Lyr last night (for about 3 hours), to find out if any superhumps are detectable. I haven't reduced the CCD images yet, but let you know my findings. Has anyone else attempted CCD photometry on this object ? Or does anyone know about published photometric results ?
The DM Lyr CCD photometry, obtained last night (July 16/17) at the CBA Belgium (unfiltered 90s exposures using a 25-cm SCT with ST-7 CCD) clearly shows the existence of superhumps in this system (hence proving the SU UMa nature). A very preliminary analysis of the superhump period yields a best value of 0.067d +/- 0.001d (PDM method) and a mean amplitude of 0.08 mag. These values correspond very well with the results obtained independently by the Ouda team of Kyoto University, Japan.
At the moment of this writing, the telescope is performing another CCD photometry run on DM Lyrae (July 17/18).
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