------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 3087 2015 Jun 28 20.17UT 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 ------------------------------------------------------------------- ASASSN-15lp: PROBABLE SUPERNOVA IN MRK 0576 S. Kiyota, Japan et. al. report on The Astronomer's Telegram 7691 discovery of a probable supernova in MRK 0576 during the ongoing All Sky Automated Survey for SuperNovae (ASAS-SN), using data from the quadruple 14-cm "Brutus" telescope in Haleakala, Hawaii. It is located at: RA 01:49:10.32 DEC +05:38:23.32 (2000) ASASSN-15lp was discovered in images obtained on UT 2015 Jun 20.61UT at V~15.1 mag. It was also detected on images obtained on UT 2015 Jun 21.61 at V~15.2. It was not detected to V=16.8 in images taken of 2015 Feb 08.21UT and before. Multiple confirmation images, including an image obtained on 2015 Jun 20.98 with the LCOGT 1-m robotic telescope in Cerro Tololo, Chile, confirm the discovery of the transient. The position of ASASSN-15lp is approximately 1.1" South and 1.0" East from the centre of the host galaxy and an absolute V-band magnitude of approximately -19.3 is calculated. V404 CYGNI Further to TA E-Circular 3084, John Scarpaci, Wheaton College, MA reports on ATEL 7721 V-band observations of the transient X-ray binary system V404 Cygni using a 12" Meade LX600 telescope equipped with an SBIG STT-8300M CCD in Wheaton College Observatory during the night of 2015 June 24-25 (local time). The source is currently in outburst and observers at all wavelengths have reported strong variability and flaring activity. Their observations spanned from 2015 June 25 03:33-07:55 UT. During this time they employed an automated observing sequence consisting of repeated blocks of 30s science exposures followed by a 5s gap for CCD readout. This was continued throughout the night with the exception of a few 1-2 minute interruptions to clear condensation on the telescope optics, resulting in 429 usable images. Three field stars were used whose V-band magnitudes from the AAVSO database. Preliminary results indicate that the average V-band brightness during their observations was 12.1 mag, with no clear increasing or decreasing trend in the baseline optical flux. This is consistent with results presented by Martin-Carrillo et al. (ATEL #7718) who noted that the flux has remained constant since June 20. As noted in previous optical reports of this outburst, they also see strong variability and flaring in few-minute timescales. While flux changes were relatively small (~0.3mag) during the first hour of our observations, the source then entered a state of rapid variability with large amplitudes. Especially, They note that during one such fluctuations, starting at around MJD 57198.310, the flux dropped from ~11.5 mag (close to the highest flux they observed during our observing run) to ~13.5 mag (the lowest flux we observed during our run), i.e. by a factor of about 6.3x in ~15 minutes and then recovering to the baseline level in another ~15 minutes. Guy M Hurst