Electronic Telegram No. 422
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 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


SUPERNOVAE 2006Y AND 2006ai
     N. Morrell and G. Folatelli, on behalf of the Carnegie Supernova
Project, report that spectroscopy (range 380-930 nm) of SN 2006Y (cf.
IAUC 8668), obtained on Feb. 27.14 UT with the Las Campanas 2.5-m du
Pont telescope (+ WFCCD spectrograph), showing it to be a type-II
event, nearly one month after explosion.  A spectrum of the apparent
nucleus of the host galaxy was also obtained, from which is derived a
recession velocity of 10074 km/s (redshift 0.0336 +/- 0.0001).  From
nebular emission lines superimposed on the supernova spectrum, a
slightly different redshift of 0.0333 +/- 0.0001 is derived; using
this value, an expansion velocity of 7650 km/s for this supernova is
derived from the minimum of the H_beta absorption.  A redshift of
0.0341 +/- 0.0002 was also measured for ESO 207-G27 (a galaxy located
southeast of the supernova host).
     A spectrum of SN 2006ai (cf. IAUC 8674), obtained on Mar. 5.12 with
the same instrumental configuration, shows it to be a type-II supernova,
at least one month after explosion, for which an expansion velocity of
8050 km/s is derived from the minimum of the H_beta absorption,
considering a redshift of 7426 km/s (z = 0.0158 +/- 0.0001) measured
from emission lines in the spectrum of the host galaxy.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2006 CBAT
2006 March 7                     (CBET 422)               Daniel W. E. Green