Central Bureau for Astronomical Telegrams
IAUC 5969: 1994I; PU Vul
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Circular No. 5969
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 1994I IN NGC 5194
R. Chini, H.-P. Gemuend, G. Haslam, E. Kreysa, P. Lambertz,
and R. Zylka, Max-Planck-Institut fur Radioastronomie, Bonn; and R.
Tuffs, Max-Planck-Institut fur Kernphysik, Heidelberg, report the
detection of SN 1994I at 1.3 mm using the IRAM 30-m telescope (+
MPIfR 7-element bolometer array): "Observations indicate that the
emission at this wavelength is essentially constant over 2 days.
The central beam of the hexagonal array was pointed towards the
optical position of SN 1994I (IAUC 5961). No discrete sources were
detected in the six surrounding beams, which are offset 22" from
the central beam. The angular resolution was 11" (FWHM). The
following flux densities were derived by subtracting the average of
flux in the surrounding beams from the central one; they therefore
represent the excess flux at the position of the supernova over the
diffuse emission from M51: Apr. 6.07 UT, 9.0 +/- 2.0 mJy; 7.00,
8.4 +/- 0.6; 8.04, 8.2 +/- 1.0. The errors denote 1-sigma random
uncertainties. The calibration of the absolute flux scale, which
was made using Uranus (assuming a temperature of 101 K for the
planet's disk), introduces an additional systematic uncertainty of
10 percent. The 1.3-mm measurements lie below an extrapolation in
epoch and observing frequency of the VLA measurements (IAUC 5966).
Optical-depth effects, inverse Compton processes near maximum light,
and intrinsic particle acceleration time scales in the source could
all contribute to this different behavior. Monitoring at 1.3 mm
will continue."
PU VULPECULAE
P. Garnavich, Dominion Astrophysical Observatory, writes: "A
spectrogram (range 465-505 nm) of PU Vul was obtained with the DAO
1.2-m telescope on Apr. 1.5 UT. The broad He II 468.6-nm emission
feature, seen for the past four years, is absent. Compared with a
spectrum obtained in July 1993, the strength of He II is down by at
least a factor of ten relative to H-beta and supports the suggestion
that an eclipse of the hot source is in progress (IAUC 5960). The
equivalent width of H-beta has increased between these two
observations, which implies that the continuum around 480 nm has
become weaker. The nebular lines of [O III] at 495.9/500.7 nm have
strengthened relative to H-beta by about 15 percent since July 1993,
but this may be unrelated to the eclipse and due to the slowly
increasing temperature of the source."
1994 April 8 (5969) Daniel W. E. Green
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