Electronic Telegram No. 850
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)
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SUPERNOVA 2007aa IN NGC 4030
     G. Folatelli, Las Campanas Observatory, La Serena, reports the
confirmation of 2007aa (cf. CBET 848), which was detected in a series
of dithered Y-, J-, and H-band images obtained by S. Gonzalez on Feb.
19.26-19.28 UT with the 1-m Swope telescope (+ RetroCam) at Las
Campanas Observatory.  The supernova is located at R.A. = 12h00m27s.67,
Decl. = -1o04'51".5 (equinox 2000.0), as measured on the mosaic of
Y-band images; the offset is 60".8 east and 68".5 north of the nucleus
of NGC 4030.  An approximate J-band magnitude of 15.1 was computed for
2007aa by comparison with a nearby star in the 2-MASS catalogue.
A spectrogram was obtained by N. Morrell on Feb. 19.24 with the 2.5-m
du Pont telescope (+ WFCCD spectrograph) at Las Campanas Observatory,
revealing 2007aa to be a type-II supernova.  The spectrogram resembles
that of SN 1999em obtained 20 days after explosion.  Strong Balmer, Ca
II, and Fe II lines are present with P-Cyg profiles.  Adopting the NED
recession velocity of 1465 km/s for the host galaxy (Koribalski et al.
2004, A.J. 128, 16), the following expansion velocities are derived
from the absorption minima of different spectral lines:  H-beta, 6000
km/s; Fe II 5169, 5300 km/s; Ca II H and K (blend), 6800 km/s.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2007 CBAT
2007 February 19                 (CBET 850)               Daniel W. E. Green