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Circular No. 6638
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science)
URL http://cfa-www.harvard.edu/cfa/ps/cbat.html
Phone 617-495-7244/7440/7444 (for emergency use only)
COMET C/1995 O1 (HALE-BOPP)
A. Fitzsimmons, Queen's University, Belfast; and G. Cremonese,
Astronomical Observatory, Padua, on behalf of the European Hale-
Bopp Team, report on further observations of the tails of comet
C/1995 O1 (cf. IAUC 6631, 6634): "The 4.2-m William Herschel
Telescope (+ Utrecht Echelle Spectrograph) at Observatorio del
Roque de los Muchachos was used on Apr. 23.9 and 24.9 UT to obtain
spectra with a 4'.5 x 1".1 slit at various positions on the dust
tail up to 2 deg from the nucleus. Broad sodium emission lines
were seen at all locations, with a blue edge corresponding to the
geocentric velocity of the comet and a width of typically about 50
km/s. These observations imply that dust grains are a major source
of sodium in this comet. We also report the detection with the
same instrument of neutral potassium (769.9 nm) emission associated
with the comet in spectra obtained on the nucleus and at a distance
of 10" on Apr. 20.9."
V1333 AQUILAE
S. A. Ilovaisky and C. Chevalier, Observatoire de Haute-
Provence, communicate: "Subsequent to the x-ray detection of Aquila
X-1 with the XTE All Sky Monitor around mid-Jan. (IAUC 6558), the
optical counterpart of this recurrent transient was observed with
the 1.2-m telescope on Feb. 20 and found to be bright. Images
taken on Mar. 30 show that the object had already faded to
quiescence. The XTE ASM quick-look x-ray lightcurve, publicly
available on the Web at http://space.mit.edu/XTE/asmlc/srcs/ASM.html
,
shows that the source had turned off by early Mar. During the
previous activity cycle, the optical object was observed at Haute-
Provence between 1996 Feb. 28 and Oct. 12. Optical turn-on was
detected on 1996 May 29 (IAUC 6416) and optical turn-off on Aug. 19.
Both of these dates agree closely (within one or two days) with
those derived from the ASM data for that low-intensity event."
SUPERNOVAE 1997bp, 1997bq, AND 1997bs
Unfiltered CCD magnitude estimates by S. Moretti and S.
Tomaselli, Forli, Italy, with a 0.35-m telescope (reference stars
from GSC): SN 1997 bp in NGC 4680, Apr. 23.86 UT, 15.0; SN 1997bq
in NGC 3147, Apr. 18.92, 14.8; SN 1997bs in NGC 3627, Apr. 23.89,
17.4.
(C) Copyright 1997 CBAT
1997 April 28 (6638) Daniel W. E. Green
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