Electronic Telegram
No. 2034
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138,
U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT@CFA.HARVARD.EDU (science)
URL http://www.cfa.harvard.edu/iau/cbat.html


V496 SCUTI
U. Munari and A. Siviero, Istituto Nazionale di Astrofisica, Padova Astronomical Observatory; 
and P. Valisa, S. Dallaporta, and L. Baldinelli, Asiago Novae and Symbiotic Stars (ANS) 
collaboration, report that a tight monitoring of Nova Sct 2009 has been carried out daily 
since announcement of its discovery (cf. IAUC 9093). The nova has displayed a steady 
rise toward maximum, which was reached around Nov. 19.2 UT at B = 7.86, B-V = +0.76, 
V-R_c = +0.50, V-I_c = +1.02. The latest measurement on Nov. 20.7 gives B =8.01, 
B-V = +0.71, V-R_c = +0.49, V-I_c = +1.02. It took 8.0 days for the nova to rise 
the final 1 mag in brightness toward maximum. 
Low-resolution absolute spectrophotometry (range 390-860 nm, dispersion 0.21 nm/pixel) 
and high-resolution echelle spectroscopy (resolving power 20000, range 395-865 nm) has 
been obtained with the Asiago 1.82-m and Varese 0.6-m telescopes at various dates, 
showing that the nova has significantly changed its spectral
appearance while rising toward maximum. On Nov. 19.8 and 20.8 UT, the spectra are still 
dominated by Balmer and Fe II emission lines, as they were at the time of discovery 
(cf. IAUC 9093), with now also strong Na I, Ca II (393, 397, 849, 854, 866 nm), 
and O I (777 and 845 nm). All emission lines present similar and highly structured 
P-Cyg profiles. The broad and single absorption component, which dominated the P-Cyg 
profile at the time of discovery, is now replaced by two much-sharper components. For 
the Fe II multiplet-42 lines, the two absorptions are located at heliocentric velocities 
of -785 and -360 km/s, and their FWHM are 260 and 90 km/s, respectively. Also, the 
FWHM of the emission lines has decreased, now being 600 km/s. The H_alpha:H_beta:H_gamma:
H_delta integrated emission flux ratio is now 3.05:1.00:0.35:0.23, flatter than at the 
time of discovery, and that of O I 777.2/844.6 has reversed to 1.18. 
The integrated flux of the H_beta emission has increased from 3.0 x 10**(-11) 
erg cm**(-2) s**(-1) on Nov. 9.8 to 1.1 x 10**(-10) erg cm**(-2) s**(-1) on Nov. 19.8.

NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
superseded by text appearing later in the printed IAU Circulars.

(C) Copyright 2009 CBAT
2009 November 21 (CBET 2034) Daniel W. E.
Green