Central Bureau for Astronomical Telegrams

Central Bureau for Astronomical Telegrams -- Image credits

IAUC 7693: 2001dy; 2001dr; V857 Cen

The following International Astronomical Union Circular may be linked-to from your own Web pages, but must not otherwise be redistributed (see these notes on the conditions under which circulars are made available on our WWW site).

Read IAUC 7692  SEARCH Read IAUC 7694

View IAUC 7693 in .dvi or .ps format.
IAUC number

                                                  Circular No. 7693
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)

SUPERNOVA 2001dy IN MCG +04-40-16
     T. Puckett and M. Marcus, Mountain Town, GA, report the
discovery of an apparent supernova (mag 18.0) on an unfiltered CCD
frame (limiting mag 19.4) taken with the Puckett Observatory 0.30-m
automated patrol telescope on Aug. 27.12 UT.  SN 2001dy is located
at R.A. = 17h04m59s.42, Decl. = +23o10'06".2 (equinox 2000.0),
which is 5".9 west and 2".8 south of the center of MCG +04-40-16.
The new object was confirmed on CCD frames taken on Aug. 28.07 by
Puckett with a 0.60-m reflector.  SN 2001dy is not present on
images taken by Puckett in 1999 (Aug. 10 and 17) and 2000 (Mar. 31,
Apr. 30, May 9, and June 2; limiting mag about 20.5), neither is it
present on Palomar Sky Survey images taken on 1992 Sept. 7, 1990
Apr. 28 (limiting mag about 21.0), and 1955 Apr. 1 (limiting mag
about 19.7).

SUPERNOVA 2001dr IN NGC 4932
     S. Benetti, G. Altavilla, E. Cappellaro, A. Pastorello, and M.
Turatto, Astronomical Observatory, Padua; and A. Della Valle,
Astronomy Department, Padua, write:  "A reduced CCD spectrum (range
380-770 nm, resolution 2.5 nm) of SN 2001dr (cf. IAUC 7684),
obtained on Aug. 25.83 UT with the Asiago 1.82-m telescope (+
AFOSC), is that of a type-II supernova, about 1 week after maximum
light.  The spectrum shows a broad H-alpha emission with a P-Cyg
absorption having a minimum measured at 649.7 nm.  Adopting the
NASA/IPAC Extragalactic Database recession velocity for NGC 4932 of
7088 km/s, we find an expansion velocity of about 9800 km/s."

     J. J. M. in 't Zand, Astronomical Institute, Utrecht
University, and Space Research Organization Netherlands (SRON),
Utrecht; R. Mewe and J. Heise, SRON, write:  "Analysis of archival
data from the Wide Field Cameras on BeppoSAX has revealed an
energetic x-ray flare from a position consistent with that of V857
Cen = Gliese 431, a dM4.5e star (V = 11.5) at a distance of 10.5 pc
that was seen to flare once before in the optical (Doyle et al.
1990, A.Ap. Suppl. 86, 403).  The x-ray flare occurred on May
28.739 UT, had a rise time of 1 to 3 min, and lasted at least 12
min.  After a data gap from 12 to 88 min after the onset, the flare
was over.  The peak luminosity is 3 x 10**31 erg s**-1 cm**-2 (2-28
keV), and the fluence at least 2 x 10**34 ergs.  The spectral shape
is consistent with thermal bremsstrahlung at 11 +/- 4 keV.  This is
the only flare detected from Gl 431 above 1 x 10**31 erg s**-1
cm**-2 in 1 month of net exposure time over the past five years."

                      (C) Copyright 2001 CBAT
2001 August 28                 (7693)            Daniel W. E. Green

Read IAUC 7692  SEARCH Read IAUC 7694

View IAUC 7693 in .dvi or .ps format.

Our Web policy. Index to the CBAT/MPC/ICQ pages.

Valid HTML 4.01!