Central Bureau for Astronomical Telegrams
IAUC 4727: 1989B; 1989A
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Read IAUC 4728
Circular No. 4727
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 or GREEN@CFA.BITNET MARSDEN or GREEN@CFAPS2.SPAN
SUPERNOVA 1989B IN NGC 3627
H. Marvin and S. Perlmutter, Berkeley Automated Supernova Search,
report that SN 1989B was present in images of NGC 3627 taken on Jan.
21.31 and 30.29 UT. On the former night it was 4 mag fainter than on
the latter and thus about mag 17. The slow risetime suggests a type I
supernova and that maximum may not yet have been reached.
D. Seal, Milan; E. Poretti, Milan Observatory; and E. Cappellaro
and M. Turatto, Asiago Astrophysical Observatory, report the independent
discovery of the object by Federico Manzini, Novara, on Jan. 30.9 UT.
The discovery was made visually and confirmed photographically.
Cappellaro and Turatto also report: "A spectrum (range 430-710 nm)
was secured by L. M. Buson with the 1.82-m telescope (Boller and Chivens
spectrograph + CCD) at Cima Ekar on Jan. 31.1 UT. The uncalibrated
spectrum shows at 613 nm the Si II feature typical of type Ia
supernovae. Other broad absorptions are located at 580, 550 and 532.5
nm, indicating that the object is close to the maximum."
R. Kirshner, Center for Astrophysics, reports that spectra
obtained by B. Wilkes with the Multiple Mirror Telescope and by J. Peters
with the 1.5-m reflector at the Whipple Observatory on Jan. 31.4 UT
show that the supernova is of type Ia.
SUPERNOVA 1989A IN NGC 3687
L. M. Buson, E. Cappellaro and M. Turatto, Asiago Astrophysical
Observatory, obtained spectra (range 420-720 nm) of this supernova on
Jan. 27 and 29 with the Boller and Chivens spectrograph + CCD on the
1.82-m telescope at Cima Ekar and confirmed the object to be of type Ia
(IAUC 4724). The Si II absorption at 613 nm corresponds to an expansion
velocity of 13 000 km/s, and other features are measured at 498, 527 and
546 nm. The high expansion velocity, the presence of S II lines (564
and 545 nm) and the absence of the Na I 589.2 nm line indicate that the
object was observed within ten days of maximum light.
T. J. Balonek and S. E. Martin, Colgate University; R. Elston,
National Optical Astronomy Observatories; P. A. Heckert, Western Carolina
University; and P. S. Smith, Steward Observatory, report that photometric
measurements (20" aperture) of SN 1989A on Jan. 30.44 UT with the
University of Arizona's 1.54-m Catalina telescope gave V = 13.9 +/- 0.1,
B = 14.0 +/- 0.1.
1989 January 31 (4727) Brian G. Marsden
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