Central Bureau for Astronomical Telegrams

Central Bureau for Astronomical Telegrams -- Image credits

IAUC 4979: 1990B; SW UMa; MWC 560; 1989c1

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 4978  SEARCH Read IAUC 4980
IAUC number

                                                  Circular No. 4979
Central Bureau for Astronomical Telegrams
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

     R. A. Sramek, National Radio Astronomy Observatory; K. W.
Weiler, Naval Research Laboratory; and N. Panagia, Space Telescope
Science Institute, report radio detection of the type-Ib SN 1990B.
Observations made on Feb. 13 with the Very Large Array in A array
at 20-cm wavelength show a detection of a 1.0-mJy (+/- 0.15 mJy)
radio source at R.A. = 12h34m02s.17, Decl. = +11 31'00".2 (equinox
1950.0; +/- 0".2 in each coordinate), coincident to within the errors
of the optical supernova position.  Detections were also obtained
during the same observing session at 6 and 3.4 cm at approximately
the 1-mJy level, but the calibrations must still be checked.
Monitoring of the radio emission from the supernova is continuing.

     This dwarf nova is undergoing a rare outburst, the last of
which occurred in 1986 (cf. IAUC 4188), as indicated by the following
visual magnitude estimates:  Mar. 12.84 UT, [14.7 (D. Stott,
Winchester, England); 13.78, 10.8 (P. Schmeer, Bischmisheim, West
Germany); 13.85, 10.7 (G. Hurst, Basingstoke, England); 13.87, 10.4
(S. Lubbock, Bridgend, Wales).

MWC 560
     S. P. Maran, A. G. Michalitsianos, and R. Oliversen,
Laboratory for Astronomy and Solar Physics, Goddard Space Flight
Center, report:  "An optically-thick shell appears to have been
ejected at a novalike velocity of approximately -3000 km/s, as
shown by a comparison of the strong absorption spectrum attributed
to Fe II and other low excitation lines in recent IUE spectra (Feb.
4.02 and Mar. 7.04 UT) with that obtained by H. Bond on 1984 Mar.
13, when the same features were observed at rest velocity."

     Total visual magnitude estimates (cf. IAUC 4975):  Mar. 5.93
UT, 6.8 (V. F. de Assis Neto, Sao Francisco de Oliveira, Brazil,
10x70 binoculars); 7.50, 6.6 (A. Pearce, Scarborough, W. Australia,
20x80 binoculars); 11.50, 6.5 (Pearce); 13.49, 6.4 (Pearce);
14.49, 6.3 (Pearce).

1990 March 14                  (4979)             Daniel W. E. Green

Read IAUC 4978  SEARCH Read IAUC 4980

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

Valid HTML 4.01!