[IAUC] IAUC 8948: V5579 Sgr; N Oph 2008 [25139-2008/05-R1]
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Mie Mayo 28 00:51:23 ART 2008
Circular No. 8948
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
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V5579 SAGITTARII
R. W. Russell, R. J. Rudy, and D. K. Lynch, The Aerospace
Corporation; C. E. Woodward, University of Minnesota; and H. Marion,
University of Texas and Texas State University, report observations
of V5579 Sgr (cf. IAUC 8937, 8940) on May 9 UT at the Infrared
Telescope Facility (+ SPEX; range 0.8-5.2 microns). D. Griep, IRTF,
helped to acquire the data. The nova was at a very early stage of
its spectral development, showing lines of O I, N I, and Ca II, and
exceptionally strong lines of C I. Lines widths were approximately
1600 km/s at FWHM. Fe II features were weak, but -- despite that
fact -- this is almost certainly an "Fe II"-type of nova. Lines of
neutral helium had not yet formed. The strongest lines in the
infrared spectrum are the O I lines that are fluourescently excited
by Lyman_beta. These lines indicate a reddening of E(B-V) = 1.2,
some of which may be local to the nova, which has already formed
dust. In fact, the infrared continuum is dominated by thermal
emission from dust at a single temperature of 1370 K.
NOVA OPHIUCHI 2008
K. Ayani and N. Murakami, Bisei Astronomical Observatory (BAO),
write that low-resolution spectra (range 400-800 nm; resolution 0.5
nm at H_alpha) of the apparent nova announced on IAUC 8947,
obtained with the BAO 1.01-m telescope on May 26.7 UT, confirms
that the object is a nova. They show H_alpha emission (FWHM about
600 km/s) with a P-Cyg profile, its absorption minimum being blue-
shifted by 730 km/s with respect to the emission peak. H_beta and
Fe II (multiplet 42) lines also have P-Cyg profiles, although the
absorption component dominates on lines of shorter wavelength.
Further to IAUC 8947, S. Nakano reports that co-discoverers
K. Nishiyama and F. Kabashima obtained additional unfiltered CCD
frames with a 0.40-m reflector on May 26.562 UT, yielding mag 9.8
for the nova and position R.A. = 17h39m50s.94, Decl. = -23o50'01".0
(equinox 2000.0). Nakano also forwards an unfiltered CCD
observation by K. Kadota (Ageo, Japan, 0.25-m reflector) on May
26.609 that yielded mag 9.9 and a measured position identical to
that above.
Visual magnitude estimate of N Oph 2008 by W. Vollmann, Vienna,
Austria: May 26.969 UT, 10.4. Photoelectric V magnitudes by L.
Elenin, Lubertsy, Russia, contributed by E. Waagen, AAVSO: May
26.457, 10.30; 27.380, 10.14.
(C) Copyright 2008 CBAT
2008 May 27 (8948) Daniel W. E. Green
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