2008CBET.1431....1M

U. Munari and A. Siviero, Istituto Nazionale di Astrofisica, Padova Astronomical Observatory; and P. Valisa, S. Dallaporta, G. Cherini, P. Ochner, F. Castellani, L. Buzzi, M. Brienza, and V. Luppi, ANS ("Asiago Novae and Symbiotic stars") collaboration, report that the nova V2468 Cyg (cf. IAUC 8927, 8928, 8936) is experiencing a large re-brightening during its current advanced evolution. Close to maximum brightness, on Mar. 12.10 UT, the nova was measured at V = 8.09, B-V = +0.94, V-R_c = 0.71, V-I_c = +1.43. Since then, it has been showing a normal decline with superimposed rapid and irregular fluctuations of a few tenths of a magnitude in amplitude. A flat minimum in brightness was reached during the period June 8 to 17, when the nova was shining at V = 12.44, B-V = +0.44, V-R_c = +1.39, V-I_c = +1.14. Since then, its has been steadily re-brightening, reaching V = 11.64, B-V = +0.32, V-R_c = +1.18, V-I_c = +1.17 on July 2.91, thus with no significant color change associated with the re-brightening. Low-resolution spectra obtained on July 4.91 show He I, the blend at 464.0 nm, and the Balmer series in strong emission – the integrated flux of H-beta amounting to 8.2 x 10**(-12) erg/cm**2/s. [N II] 575.5-nm and [O II] 732.5-nm – with integrated fluxes of 1.6 and 1.0 x 10**(-11) erg/cm**2/s, respectively – are the strongest emission lines after H-alpha. The H-alpha emission shows more evidently the multi-peaks profile that it has been displaying during the last few months. On July 5.90, the H-alpha profile was characterized by an overall Gaussian shape with FWHM = 1430 km/s and +93 km/s heliocentric radial velocity, with major peaks at heliocentric radial velocities -585, -345, -185, -30, +120, +300, and +630 km/s.