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IAUC 7639: 2001ai, 2001aj,, 2001ak; 2001bg; V1548 Aql = N Aql 2001

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                                                  Circular No. 7639
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)

SUPERNOVAE 2001ai, 2001aj, AND 2001ak
     A. V. Filippenko and R. Chornock, University of California at
Berkeley, report that CCD spectra (range 390-1000 nm), obtained on
May 30 UT with the Keck-II 10-m reflector, reveal that SN 2001aj
(IAUC 7606) is a type-II supernova beginning to enter the nebular
phase (NED recession velocity 7940 km/s), SN 2001ak (IAUC 7607) is
a type-II supernova in the nebular phase (NED recession velocity
5280 km/s), and SN 2001ai (IAUC 7605) is a type-Ic supernova about
2 months past maximum brightness (in agreement with the report of
Matheson et al., IAUC 7605).

SUPERNOVA 2001bg IN NGC 2608
     S. Benetti, G. Altavilla, E. Cappellaro, A. Pastorello, and M.
Turatto, Padova; R. Cosentino and A. Zacchei, Telescopio Nazionale
Galileo (TNG); I. J. Danziger, Trieste; and F. Patat, European
Southern Observatory, communicate:  "On May 12.92 UT, we obtained a
high-resolution spectrum (range 464-782 nm, resolution 0.011 nm)
with the TNG (+ SARG) of the type-Ia SN 2001bg (cf. IAUC 7626).
The spectrum shows Na I D absorptions originating both in the Milky
Way (equivalent width, EW = 0.026 nm for the doublet) and in two
extragalactic clouds with recession velocities of 2136 and 2171
km/s, respectively -- likely associated with the supernova's parent
galaxy (the recession velocity for NGC 2068 archived in NED is 2135
km/s).  The total Na I D EW from the extragalactic clouds is 0.125
nm.  Schlegel et al. (1998, Ap.J. 500, 525) give E(B-V) = 0.039 for
the galactic absorption in the direction of NGC 2068.  Assuming
that the (Na I D)-dust ratio for the extragalactic clouds is the
same as for the galactic component, we estimate E(B-V) about 0.19
for the extinction of SN 2001bg in the parent galaxy.  The presence
of possible nearby dust clouds makes SN 2001bg a good candidate for
the search of a late light echo.  We found no sign in the spectrum
of narrow H-alpha absorptions/emissions (EW < 0.007 nm for
unresolved features)."
     CCD R photometry by K. Hornoch, Lelekovice, Czech Republic:
May 10.836 UT, 13.78; 11.919, 13.74; 13.876, 13.77; 20.847, 14.01;
25.843, 14.27.

     N. N. Samus, Institute of Astronomy, Moscow, informs us that
the designation V1548 Aql has been given to this nova (cf. IAUC
7627, 7628).

                      (C) Copyright 2001 CBAT
2001 May 30                    (7639)            Daniel W. E. Green

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