2007CBET.1099....1M

U. Munari and A. Siviero, Istituto Nazionale di Astrofisica, Padova Astronomical Observatory; A. Henden, AAVSO; and P. Ochner, C. Simoncelli, S. Tomasoni, F. Moschini, and S. Dallaporta, ANS (Asiago Novae and Symbiotic stars) collaboration, report that the nova V1280 Sco is steadily regaining brightness after a prolonged faint state during its advanced decline. Discovered around magnitude 9.7 on Feb. 4.85 UT (cf. IAUC 8803), V1280 Sco peaked in brightness on Feb. 16 (cf. IAUC 8807, 8809); on that date, Munari et al. measured B = 4.75, B-V = +0.51, V-R_c = +0.34, V-I_c = +0.70 with respect to the B/V/R_c/Ic photometric sequence calibrated by Henden and Munari (2007, IBVS 5771). An initial slow decline turned into a rapid decline eleven days past maximum, taking the nova from B = 7.07, B-V = +0.20, V-R = +1.04, and V-I_c = +1.29 on Mar. 2.49 to B = 13.25, B-V = +0.22, V-R = +1.28, and V-I_c = +2.00 on Mar. 20.44, according to their measurements. The nova then continued to decline at a slower rate and with an irregular pattern until a minimum brightness was reached around 80 days past maximum: in the first week of May, B = 15.18, B-V = +0.69, V-R = +1.25, and V-I_c = +2.37. This was followed by a re-brightening phase lasting a month, which peaked at B = 13.31, B-V = +1.08, V-R = +1.20, and V-I_c = +2.51 on May 22. The following two months (between June 18 and Aug. 18) were spent by the light curve of V1280 Sco being in a flat and faint state characterized by mean values B = 17.0, V-R = +1.1, V-I_c = +1.5, and B-V increasing from +0.7 to +1.4. After this faint state, the nova is on the rise again, gaining 2.4 mag in B in twenty-six days. On Sept. 12.8, B = 15.50, B-V = +1.65, V-R = +1.03, V-I_c = +1.94, while on Oct. 8.74, B = 13.11, B-V = +1.19, V-R = +0.87, V-I_c = +1.51. Spectroscopic observations of this unexpected large re-brightening are encouraged.