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IAUC 7206: 1999co; 1999cp; V382 Vel

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IAUC number

                                                  Circular No. 7206
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)

     S. Jha, P. Garnavich, P. Challis, and R. Kirshner, Harvard-
Smithsonian Center for Astrophysics, report that a spectrum of SN
1999co (cf. IAUC 7205), obtained by M. Calkins with the F. L.
Whipple Observatory 1.5-m telescope (+ FAST spectrograph) on June
20.5 UT, shows it to be a type-II supernova at an early epoch.  The
spectrum exhibits a blue continuum with P-Cyg Balmer lines and He I
absorption.  Narrow emission lines of H-alpha and [O III] yield a
recession velocity for the host galaxy of 9260 km/s.  The
photospheric expansion velocity of the supernova is 9000 km/s,
measured from the absorption minima of H-beta and H-gamma.  A. V.
Filippenko, University of California at Berkeley, reports that a
CCD spectrum of SN 1999co, obtained by D. Stern on June 20 UT with
the Shane 3-m reflector at Lick Observatory, exhibits prominent
H-alpha emission, indicating a type-II event; the P-Cyg profiles
are well developed.

SUPERNOVA 1999cp IN NGC 5468
     Jha et al. write:  "A spectrum of SN 1999cp, obtained by M.
Calkins on June 19.2 UT with the F. L. Whipple Obs. 1.5-m telescope
(+ FAST spectrograph), reveals it to be a type-Ia supernova well
before maximum light.  Narrow H-alpha emission from the host galaxy
yields a recession velocity of 2870 +/- 20 km/s for NGC 5468.  The
supernova photospheric expansion velocities of Ca II H+K and Si II
(rest 635.5 nm) are 19 700 km/s and 14 100 km/s, respectively,
implying that SN 1999cp is about 10 days before maximum light."
Filippenko adds (from a spectrum taken as above by Stern):  "SN
1999cp is of type Ia, at least a week before maximum brightness,
with strong Si II absorption near 610 nm.  Continued monitoring of
SN 1999cp through the coming bright run is encouraged, as it may
reach mag 14."

     K. Mukai and J. Swank, Goddard Space Flight Center, write:
"The Rossi X-ray Timing Explorer performed a public TOO observation
of V382 Vel during May 26.22-26.26 UT, about 3 days after optical
maximum.  In the band 2.5-10 keV, a nominal excess over the
estimated background of 0.58 +/- 0.11 counts/s was obtained in four
Proportional Counter Units (PCUs); however, given the fluctuations
in the cosmic x-ray background, this should not be considered a
detection.  As an approximate upper limit, 0.8 counts/s in four
PCUs would correspond to 2.5 x 10**-12 erg cm**-2 s**-1 in the band
2.5-10 keV, significantly below the BeppoSAX and ASCA detections."

                      (C) Copyright 1999 CBAT
1999 June 21                   (7206)            Daniel W. E. Green

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