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IAUC 7245: V368 Cep; 1999dn; 1999dm

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IAUC number

                                                  Circular No. 7245
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 617-495-7244/7440/7444 (for emergency use only)

     D. A. Smith and R. Remillard, Massachusetts Institute of
Technology (MIT), report on behalf of the All-Sky Monitor (ASM)
team at MIT and NASA Goddard Space Flight Center:  "During Aug. 28,
the RXTE ASM reported three significant and consecutive detections
of a bright x-ray flare, likely to originate in the variable star
HD 220140 (= V368 Cep).  This star is also the counterpart for the
weak HEAO 1 x-ray source H2311+77.  The net ASM error box is a
parallelogram (7'.5 x 16'.2) with corners (90-percent confidence,
including systematic effects; equinox J2000.0) at: R.A. =
23h19m58s.7, Decl. = +79o00'18"; 23h17m05s.2, +79o12'51";
23h17m25s.9, +79o06'00"; 23h20m17s.5, +78o53'27".  SIMBAD
catalogues show only HD 220140 within the ASM error box.  The
average source intensity (2-12 keV) in 90-s exposures was 34 +/- 13
mCrab on Aug. 28.93237, 110 +/- 14 mCrab on Aug. 28.93348, and 150
+/- 13 mCrab on Aug. 28.93460.  Observations of this location
before and after the flare measured 2-sigma upper limits on the
source intensity of 37 mCrab on Aug. 28.56274 and 20 mCrab on Aug.
29.06626.  For a distance of 20 pc (Halliwell 1979, Ap.J. Suppl.
41, 173), the maximum luminosity observed with the ASM during this
flare was 2 x 10**32 erg/s."

SUPERNOVA 1999dn IN NGC 7714
     A. Pastorello, M. Turatto, L. Rizzi, and E. Cappellaro, Padua;
S. Benetti, Telescopio Nazionale Galileo; and F. Patat, European
Southern Observatory, report: "A new spectrogram (range 350-900 nm,
resolution 0.1 nm) of SN 1999dn was obtained with the 1.5-m
Danish telescope (+ DFOSC) at La Silla on Aug. 28.3 UT.  The
spectrum has evolved little with respect to Aug. 25.3, confirming
the strong resemblance to SNe 1997X, 1994I, and 1996aq around
maximum.  The continuum is slightly redder than at the previous
epoch and the line profiles of Ca II and Si II are more pronounced.
The Na I D line is blended with He I 587.6-nm.  Other He I lines
(667.8 and 701.5 nm) are visible, showing an expansion velocity of
about 12000 km/s.  Since the He I is not as strong as in
prototypical type-Ib supernovae, SN 1999dn should be classified as
a type-Ib/c object."

SUPERNOVA 1999dm IN MCG +05-36-022
     Corrigendum.  On IAUC 7237, line 7, for  13".1 south  read
13".1 north

                      (C) Copyright 1999 CBAT
1999 September 2               (7245)            Daniel W. E. Green

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