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IAUC 7612: 2001ay; C/1998 V7; 2001V

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                                                  Circular No. 7612
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 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://cfa-www.harvard.edu/iau/cbat.html  ISSN 0081-0304
Phone 617-495-7440/7244/7444 (for emergency use only)


SUPERNOVA 2001ay IN IC 4423
     P. Nugent, Lawrence Berkeley National Laboratory (LBNL), on
behalf of G. Aldering, I. Hook, S. Perlmutter, and L. Wang, write:
"A spectrum (range 0.5-1.0 micron) obtained on Apr. 22 UT at Keck
II (+ ESI) shows that SN 2001ay (cf. IAUC 7611) is a type-Ia
supernova, about 1 week prior to maximum light.  The redshift of
the supernova is consistent with its host galaxy.  The Si II
feature near 580 nm is pratically absent, while the Si II feature
near 615 nm is quite strong (features typical of a normal type-Ia
event at an early epoch)."
     A. Conley and R. Gibbons, LBNL, report that photometry taken
with the Cerro Tololo 0.9-m telescope show that SN 2001ay has
brightened since Apr. 18 (see IAUC 7611) and is currently at V =
16.7.
     T. Matheson, S. Jha, P. Challis, and R. Kirshner, Harvard-
Smithsonian Center for Astrophysics, report that a spectrum of SN
2001ay, obtained by M. Calkins on Apr. 21.47 UT with the F. L.
Whipple Observatory (FLWO) 1.5-m telescope (+ FAST spectrograph),
confirms it to be a type-Ia supernova near maximum.  Adopting the
NASA/IPAC Extragalactic Database recession velocity of 9067 km/s
for the host galaxy, the supernova expansion velocity is about
14 700 km/s for Si II (rest 635.5 nm).  The spectral-feature age of
the supernova (Riess et al. 1997, A.J. 114, 722) is 1 +/- 2 days
before maximum light.  An image taken by Matheson and Jha on Apr.
23.43 with the FLWO 1.2-m telescope (+ 4Shooter) shows the
supernova at V = 16.7.


COMET C/1998 V7 (SOHO)
     Further to IAUCs 7585 and 7606, D. Hammer reports his
measurements of another very faint Kreutz sungrazing comet found by
M. Oates in archival C2 coronagraph images at the SOHO website.
The reduced measurements and orbital elements by B. G. Marsden
appear on MPEC 2001-G34.

     1998 UT           R.A. (2000) Decl.
     Nov.  7.221      14 43.9      -17 34


SUPERNOVA 2001V IN NGC 3987
     CCD R photometry by K. Hornoch, Lelekovice, Czech Republic
(0.35-m reflector):  Feb. 24.880 UT, 15.1; 27.837, 14.8; Mar.
6.910, 14.7; 18.851, 15.1; Apr. 1.845, 15.3; 2.843, 15.2; 3.863,
15.4; 14.844, 15.6.

                      (C) Copyright 2001 CBAT
2001 April 23                  (7612)            Daniel W. E. Green

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