Brandt, Søren

Castro-Tirado, A. J.

Lund, Niels

Online Research Database In Technology

                       General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.  • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal   If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.     Downloaded from orbit.dtu.dk on: Dec 20, 2017GRB J0444-0700Brandt, Søren; Lund, Niels;  Castro-Tirado, A. J.Published in:International Astronomical Union Circulars (IAUC)Publication date:1993Document VersionPublisher's PDF, also known as Version of recordLink back to DTU OrbitCitation (APA):Brandt, S., Lund, N., &  Castro-Tirado, A. J. (1993). GRB J0444-0700. International Astronomical UnionCirculars (IAUC), (5759).                                                 Circular No. 5759 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Postal Address: Central Bureau for Astronomical Telegrams Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. Telephone 617-495-7244/7440/7444 (for emergency use only) TWX 710-320-6842 ASTROGRAM CAM     EASYLINK 62794505 MARSDEN@CFA or GREEN@CFA (.SPAN, .BITNET or .HARVARD.EDU)   SUPERNOVA 1993J IN NGC 3031      S. D. Van Dyk and K. W. Weiler, Naval Research Laboratory; M. P. Rupen and R. A. Sramek, National Radio Astronomy Observatory; and N. Panagia, Space Telescope Science Institute, report:  "New observations of SN 1993J made on Apr. 8.33 UT with the Very Large Array in 'B' configuration show that the source is now detectable in at least three frequency bands.  This confirms the first weak detection (IAUC 5752) of the supernova at 1.3 cm (22.5 GHz) on Apr. 2.30.  The source has now risen dramatically in flux density at 1.3 cm to 18.94 +/- 0.20 mJy at R.A. = 9h51m19s.042, Decl. = +69 15'26".45 (equinox 1950.0; +/- 0".2 in each coordinate), in excellent agreement with the previously reported position.  The radio position for SN 1993J, compared with the radio position for the nucleus of NGC 3031 given on IAUC 5752, yields an offset for the supernova of 44".0 west, 161".8 south.  The supernova is also detected at 2.0 cm (14.9 GHz) with flux density 8.04 +/- 0.18 mJy, confirming the previous detection made at this wavelength by Pooley and Green (IAUC 5751), and at 3.6 cm (8.4 GHz) with flux density 0.74 +/- 0.05 mJy.  The radio spectrum of the supernova is optically thick, as is expected at this time.  Comparison with the type-II linear radio supernovae 1979C and 1980K shows that SN 1993J has turned on in the radio significantly earlier than the two previous supernovae.  This implies that there is less absorption external to the radio emitting source for SN 1993J and therefore, from modelling, that the progenitor of SN 1993J was probably less massive than the progenitors of the other two radio supernovae, assuming that SN 1993J is type-II/linear as were SNe 1979C and 1980K; if the supernova is type-II/plateau, then its behavior in the radio is unpredictable, since a supernova with this subtype has never been previously detected at radio wavelengths.  Radio monitoring is continuing on a nearly daily basis at these and other wavelengths in order to follow the supernova's rapidly changing behavior."   GRB J0444-0700      S. Brandt, N. Lund, and A. J. Castro-Tirado, Danish Space Research Institute, report: "A bright gamma-ray burst was detected by the WATCH wide-field instrument on EURECA on Apr. 10.59661 UT.  The burst was located at R.A. = 4h44m, Decl. = -7 00' (equinox 2000.0). The radius of the error circle is 45'.  Follow-up observations in the optical and radio are encouraged."   1993 April 12                  (5759)            Daniel W. E. Green  

GRB J0444-0700

http://orbit.dtu.dk/ws/files/52280739/IAU_Circular_5759_1993.pdf

GRB J0444-0700

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