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IAUC 7982: V838 Mon; 2001gd; V4743 Sgr

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IAUC number

                                                  Circular No. 7982
Central Bureau for Astronomical Telegrams
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
URL http://cfa-www.harvard.edu/iau/cbat.html  ISSN 0081-0304
Phone 617-495-7440/7244/7444 (for emergency use only)

     S. Desidera and U. Munari, Asiago Astrophysical Observatory,
report:  "Spectroscopic observations (ranges 437-774 nm at 0.32
nm/pixel, 625-805 nm at 0.18 nm/pixel, and 819-921 nm at 0.10
nm/pixel) of V838 Mon were obtained on Oct. 2.17 UT with the Asiago
1.82-m telescope (+ AFOSC), following conjunction with the sun.
Longward of 700 nm, the spectrum is dominated by TiO and
particularly VO absorption bands, suggesting a spectral type
slightly later than the M10-III star U Her.  Thus, a dramatic
temperature decrease of the outbursting star is contributing to the
fading at optical wavelengths and to the brightening in the
infrared observed over the last few months.  We see no H-alpha in
emission, no Ca II triplet absorption in the far red, and no P-Cyg
profiles elsewhere, thus marking a sharp contrast with the last
spectra recorded in April-May.  Shortward of 700 nm, a weak blue
continuum dominates the spectrum.  At the low S/N of our
observations, the spectrum could resemble the F0 type estimated in
quiescence for V838 Mon by Munari et al. (2002, A.Ap. 389, L51), in
which case the eruption that took V838 Mon to V = 6.7 in Feb. could
have occurred in a binary companion to the F0 star.  Deeper
observations of the blue continuum are in progress."

SUPERNOVA 2001gd IN NGC 5033
     P. Chandra and A. Ray, Tata Institute of Fundamental Research,
Mumbai; and S. Bhatnagar, National Radio Astronomy Observatory,
Socorro, report the detection of SN 2001gd at 1396.75 MHz (flux
density 3.55 +/- 0.22 mJy) with the Giant Meterwave Radio Telescope
(GMRT) on Sept. 22.22 UT.  The extended emission from the host
galaxy had a flux density of 16.2 +/- 1.7 mJy in a  8".6 x 6".8 box
centered at R.A. = 13h13m27s.5, Decl. = +36o35'36" (equinox
2000.0).  SN 2001gd was not detected (2-sigma upper limit of 0.50
mJy) with the GMRT at 616.75 MHz on May 19.84.  The flux from the
host-galaxy's center at this frequency was 92 +/- 7.2 mJy in a
29".9 x 28".2 box centered at R.A. = 13h13m27s.4, Decl. =

     N. Brown, Quinns Rocks, W. Australia, reports that this nova
was not present on nova patrol films taken on Sept. 9.6 UT
(limiting mag 12.0).  Visual magnitude estimates by A. Pearce,
Nedlands, W. Australia:  Sept. 25.505, 6.5; 26.486, 6.8; 27.498,
7.1; 29.480, 8.1; Oct. 2.535, 8.1.

                      (C) Copyright 2002 CBAT
2002 October 3                 (7982)            Daniel W. E. Green

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