(Outburst CCD image by Peter Nelson)
(Outburst CCD image by Peter Nelson)
(Outburst CCD image by Donn Starkey)
V2527 Oph
appears to be in
outburst.
The outburst position agrees with the D&S chart.
No minor planets were found at this brightness, can someone confirm.
OPHV2527 030502.614 138 Stu.RASNZ Regards, Rod Stubbings
V2527 Oph outburst!!
As reported in [vsnet-outbust 5472], the (still poorly known) SU UMa-type dwarf nova V2527 Oph = 1E1719.1-1946 = 1RXS J172204.5-194913 is undergoing a very bright outburst! The current magnitude surpasses the past record, and the object is most likely undergoing a superoutburst! The outburst must be young, and the present outburst will provide *the best* opportunity to record the superhumps in this object first-ever in detail.
The semi-accurate location of the object is reported to be 17:22:04.3 -19:49:08 (J2000.0).
The object is an X-ray source selected from Einstein survey, and later spectroscopic observation cunfirmed its CV nature. The VSNET team has been monitoring the object upon knowing that this spectrum resembles that of a short-period (presumably SU UMa-type) dwarf nova. The spectrum suggests a dwarf nova with a low mass-transfer rate, just as in WZ Sge.
CCD time-resolve observations (as long as possible, preferrably several hours per night) are strongly encouraged. Please use the usual SU UMa-type observing prescription. We are also happy to receive representative images (in FITS) for accurate astrometry and quiescence identidication. The reported quiescent magnitude is V=19.02. I will make more comments on this object later.
Good luck with your observations! YYYYMMDD(UT) mag observer 20030311.758 <144 (Rod Stubbings) 20030315.726 <144 (Rod Stubbings) 20030331.647 <144 (Rod Stubbings) 20030402.614 <144 (Rod Stubbings) 20030404.642 <144 (Rod Stubbings) 20030405.681 <144 (Rod Stubbings) 20030406.716 <144 (Rod Stubbings) 20030409.651 <144 (Rod Stubbings) 20030413.762 <146 (Rod Stubbings) 20030424.573 <140 (Rod Stubbings) 20030425.601 <144 (Rod Stubbings) 20030426.608 <144 (Rod Stubbings) 20030428.576 <148 (Rod Stubbings) 20030429.596 <146 (Rod Stubbings) 20030502.614 138 (Rod Stubbings) Regards, Taichi Kato VSNET Collaboration team
Dear Colleagues,
We started tonight observation of V2527 Oph at 14:40 (UT) at Ouda. This object is at around 14 mag. Kiyota-san and OUS observatory also observe this object.
We plan 4 hour observation.
Best Regars, Ryoko Ishioka, Akira Imada
CVs from Einstein survey
Among CVs from the Einstein Galactic survey, I have noticed two of them in ApJ 364, 251 have not been given variable star designations (others are 1E0830.9-2238 = WX Pyx, 1E1449.7-6804 = BZ Cir).
(1950.0)
name h m s o ' " Vmag Lx/Lopt Mv Vo
1E1516.6-6826 15 16 42.8 -68 27 39 17.52 0.85 9.5 12.0
1E1719.1-1946 17 19 06.6 -19 46 17 19.02 10.8 12.6 10.4
Vo represents the expected magnitude when the system undergoes a typical
dwarf nova outburst. Are they still worthy of monitoring, or the nature
already revealed?
Regards, Taichi Kato
Last morning I detected 1E 1719.1-1946 in outburst (mag 15) on an unfiltered CCD image taken on Oct. 11.098 UT. On a CCD image from the previous night the object is faint. At my request both Taichi Kato and Robert Fried took images of the field that confirm the outburst beyond any doubt.
Simbad coordinates for 1E 1719.1-1946: 17:22:04.1 -19:49:09 (J2000.0) For a finding chart see P. Hertz et al. ApJ 364, 251-258 (1990). This CV is included in DS93 and DWS97 as 'Oph2'.
I'll send more details of my observations to vsnet-alert later today.
High-speed photometry, spectroscopy, and X-ray observations during the current outburst (the first ever recorded!) are most urgently required.
Regards, PatrickP.S.:
The dwarf nova 1E 1719.1-1946 was still bright (mag 15) on an unfiltered CCD image taken with the IRO on Apr. 20.435 UT, and I would bet several million dollars (if I had them) that the current outburst is a supermaximum. The only previously observed outburst was detected by me on a 1999 Oct. 11.098 (UT) IRO image (vsnet-alert 3571), but contrary to the current brightening this previous one was very short.
SIMBAD coordinates for 1E 1719.1-1946: 17:22:04.1 -19:49:09 (J2000.0) For a finding chart see P. Hertz et al. ApJ 364, 251-258 (1990). This CV is included in DS93 and DWS97 as 'Oph 2'. A VSNet comparison star chart is available (vsnet-chart 205). Also available is a sequence by Arne Henden at ftp://ftp.nofs.navy.mil/pub/outgoing/aah/sequence/1e1719.dat
Time-resolved photometry during the current outburst is urgently required.
Clear skies, Patrick
Patrick,
I just finished analysing a CCD run on 1E 1719.1-1946, which I obtained at CBA Belgium Observatory on Apr 19/20, 2000, using my 0.35-m f/6.3 telescope (unfiltered). The light curve supports your suggestion that the present outburst indeed is a supermaximum, as the curve shows part of (likely) a superhump - amplitude at least 0.3 mag. Unfortunately, the time basis of the observation was too short (object too low in Belgian morning sky) to derive any period.
It makes no sense for me to continue monitoring this object, given the low altitude, unless there's support from other observatories, willing to take over after I have to shutdown the observatory at dawn.
Magnitude estimate : 20000420.1242 UT, 14.4
Best regards, Tonny Vanmunster CBA Belgium Observatory
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