[IAUC] CBET 2704: 20110421 : SUPERNOVAE 2011R AND 2011bs-2011bx

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                                                  Electronic Telegram No. 2704
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau en eps.harvard.edu (alternate cbat en iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


SUPERNOVAE 2011R AND 2011bs-2011bx
     [NOTE:  This item replaces that on CBET 2703; the object designated
therein as 2011by is apparently the previously-announced supernova 2011R
(cf. CBET 2645).  The designation 2011by will be re-used.]
     A. J. Drake, S. G. Djorgovski, A. Mahabal, M. J. Graham, and R. Williams,
California Institute of Technology; J. L. Prieto, Carnegie Observatories;
M. Catelan, Pontificia Universidad Catolica de Chile; E. C. Beshore and S. M.
Larson, Lunar and Planetary Laboratory, University of Arizona; and E.
Christensen, Gemini Observatory, report the Catalina Real-time Transient
Survey's discovery of several apparent supernovae in unfiltered survey images
taken at Catalina, Mt. Lemmon, and Siding Spring:

 SN       2011 UT        R.A. (2000.0) Decl.      Mag.      Offset
 2011bs   Mar. 27.35   14 36 49.84  +23 01 50.4   18.5      1" W
 2011bt   Mar. 28.30   12 52 55.22  + 7 46 51.7   19.2
 2011bu   Mar. 30.26   12 29 31.80  - 7 30 39.1   19.8
 2011bv   Mar. 30.35   13 02 53.57  - 4 02 36.0   18.8
 2011bw   Mar. 30.50   15 35 58.75  +21 18 42.8   19.2
 2011bx   Apr.  2.45    4 42 12.57  -48 44 12.6   17.1     2" W, 1" S

SN 2011bx was given the provisional designation PSN J04421257-4844126 when
posted by Drake on the Central Bureau's TOCP webpage.  Joseph Brimacombe,
Cairns, Australia, reports that he imaged 2011bx remotely using a 41-cm RCOS
telescope + U9000 CCD camera at the Macedon Ranges Observatory, near Melbourne,
Victoria, on Apr. 6.456 UT, measuring unfiltered mag 16.7 and position end
figures 12s.52, 13".8; he has posted his image at the following website URL:
http://www.flickr.com/photos/43846774@N02/5596333415/.

     J. L. Prieto, Carnegie Observatories, reports that optical spectra (range
380-920 nm; resolution 0.7 nm) were obtained of the above variables with the
du Pont 2.5-m telescope (+ WFCCD) at Las Campanas Observatory on Apr. 9 and 11
UT, showing that all are indeed supernovae.  After cross-correlation with a
library of supernova spectra using SNID (Blondin and Tonry 2007, Ap.J. 666,
1024), the following spectral classes, redshifts, and approximate phases (in
days after maximum light) were obtained:

    SN        Type    Redshift    phase
    2011R      II       0.03
    2011bs     II       0.036      +16
    2011bt     Ia       0.114      +15
    2011bu     Ia       0.149      +10
    2011bv     IIb      0.077      + 1
    2011bw     Ia       0.089      +36
    2011bx     Ia       0.058      + 1


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

                         (C) Copyright 2011 CBAT
2011 April 21                    (CBET 2704)              Daniel W. E. Green