------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 2411 2008 Jan 10 18.49UT Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise, Basingstoke, Hants, RG22 4PP,England.Telephone/FAX(01256)471074Int:+441256471074 INTERNET: GUY@TAHQ.DEMON.CO.UK Backup: gmh@wdcc1.bnsc.rl.ac.uk WORLD WIDE WEB http://www.theastronomer.org ------------------------------------------------------------------- NEW WZ SGE VARIABLE IN HYA The AAVSO advise that charts for this object (cf TA E-Circular 2410) may be generated at the following URL: http://www.aavso.org/observing/charts/vsp/index.html?pickname=VSX%20J1112 17.4-353828 Hiroyuki Maehara of VSNET reported in vsnet-alert 9806 that this object was at magnitude 14.2 on 2008 January 9, and was exhibiting common superhumps. Visual and CCD observations are both valuable; CCD time-series observations are encouraged if possible. SUPERNOVA 2007uy IN NGC 2770 Yoji Hirose, Japan reports the discovery of a magnitude 17.2 supernova on ten unfiltered CCD frames taken around 2007 Dec.31.669 UT using a 0.35-m f/6.8 Schmidt-Cassegrain telescope (limiting mag 18.0). Nakano has measured the following position: RA 09h 09m 35.40s DEC +33 07' 09.9" (2000), which is 20.6"E and 15.5"S of the centre of NGC 2770. Nothing is visible at this position on red Digitized Sky Survey images from 1998 and 2000, though there are apparently numerous H II regions nearby according to IAUC 8908. Edo Berger and Alicia Soderberg (Princeton University) report on The Astronomer's Telegram 1353 follow-up observations with the Swift/XRT which reveal a new transient source about 95 arcsec away from the SN position at RA=09:09:30.7, Dec=+33:08:19 (J2000). This position coincides with the outskirts of the host galaxy of SN2007uy (NGC 2770). The object was not detected in the previous observation and is detected only in the first 1 ksec of the new observation. During that time the light curve is FRED-like with a rise time of about 50 sec and a decay to the background level by about 600 sec. The source is not detected in the subsequent 4 ksec of data that intermittently cover 5-24 ksec after the flare. The average count rate is about 1 cps, which at the distance of NGC2770 (d=27 Mpc) corresponds to a luminosity of about 4x10^42 erg/s. This is in excess of 10^4 times the Eddington luminosity of a solar mass object. No coincident object is detected in the simultaneous Swift/UVOT data or in archival DSS and 2MASS images. Alternatively, this may be a foreground bright stellar flare (with L_X/L_bol=10^-3), but this would require a solar-type star at a distance of only 25 pc or an M dwarf at 2 pc, both of which would be detectable in optical and near-IR images. An extreme stellar flare with L_X=L_bol would require distances of about 500 and 50 pc, respectively. Given the high luminosity at the distance of NGC 2770, the light curve shape, and the integrated energy of about 10^45 erg, we hypothesize that this object may be a weak X-ray Flash, perhaps analogous to GRB980425/SN1998bw. Deep optical and near-IR observations to search for a counterpart are encouraged. Radio observations are in progress. In a further report on Telegram 1354 Alice relays that beginning at 2008 Jan 10.2 UT, the radio bright Type Ibc SN 2007uy was observed with the VLA as part of a monitoring campaign to study the non-thermal emission from the SN. It is noted that the position of the extremely bright X-ray transient within NGC 2770 (ATEL 1353) lies within the field-of-view of the radio observation. No radio source is detected at the position of the X-ray transient. Guy M Hurst