------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 2361 2007 Jly 31 13.25UT 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 ------------------------------------------------------------------- V5558 SAGITTARII U. Munari, et. al., Istituto Nazionale di Astrofisica, Padova Astronomical Observatory and others report on CBET 1010 that V5558 Sgr = Nova Sgr 2007 (cf TA E-Circulars 2329, 2350) spent the first seventy days following its discovery (on Apr. 14.78 UT) on an unusual, very protracted pre-maximum halt, during which it rose in brightness by just 1 magnitude, and they report on their CCD photometry of the nova, acquired almost daily with ANS telescopes since the object's discovery. On June 27 (when the nova was at V = 7.93, B-V = +0.90, V-Ic = +1.43), it suddenly entered a new phase characterised by a much steeper rise in brightness that took the nova to a maximum attained around July 10.0 at V = 6.53, B-V = +0.96, and V-Ic = +1.22. Starting at July 12.0 UT (when it was at V = 6.59, B-V = +1.09, and V-Ic = +1.32), V5558 Sgr entered a rapid decline that brought the nova down to V = 8.37, B-V = +1.12, V-Ic = +1.94 by July 19.96. The decline rate seems to have considerably slowed around July 19-20, in correspondence with the nova regaining the brightness of the extended pre-maximum halt. Only continued monitoring will tell if the occurring of the last month have been an isolated flare on top of an unusual, very slow, and flat photometric evolution or instead the start of a normal decline toward quiescence. So far, the light curve has been highly reminiscent of that displayed by Nova Cas 1995 = V723 Cas. Editor: This nova deserves high priority attention as its activity is clearly unusual. SUPERNOVAE 2007fu-2007gb The "Nearby Supernova Factory" collaboration reports on The Astronomer's Telegrams 1145 and 1148 the discovery of supernovae in images obtained during July 13-18 UT using the QUEST-II camera on the Palomar Oschin 1.2-m Schmidt telescope. Designations have now been added by the Central Bureau on CBETs 1007 and 1009. The discovery magnitudes are in the R-band: SN 2007 UT R.A. (2000.0) Decl. Mag. Type 2007fu July 13.3 20 30 28.88 -13 15 34.9 19.0 Ia 2007fv July 13.4 23 03 51.58 -21 08 52.2 19.7 II 2007fw July 14.2 15 21 09.14 + 2 26 26.3 19.5 IIn 2007fx July 14.3 20 55 57.48 - 5 41 54.9 18.5 Ia 2007fy July 18.2 14 47 49.47 +29 30 16.5 20.0 0.05 II 2007fz July 18.2 16 02 05.41 +29 43 34.8 16.5 0.01 II 2007ga July 18.3 22 22 07.95 -14 18 48.3 19.0 0.03 II 2007gb July 18.5 22 42 37.33 +28 18 56.4 19.4 0.10 Ia R CORONAE BOREALIS Although current reports display a scatter of over one magnitude on the same night, most observers are indicating it has faded below magnitude 8 and thus may be entering a full decline. We encourage observers to monitor it nightly and send reports monthly to the TA variable star editor for inclusion in the magazine vs column. Guy M Hurst