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Circular No. 7541
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)
CBAT@CFA.HARVARD.EDU (science)
URL http://cfa-www.harvard.edu/iau/cbat.html ISSN 0081-0304
Phone 617-495-7440/7244/7444 (for emergency use only)
COMET 73P/SCHWASSMANN-WACHMANN 3
Z. Sekanina, Jet Propulsion Laboratory, writes: "Preliminary
analysis of the astrometric data reported for components C, B, and
E indicates that E is not a recently separated fragment; it broke
off from C in mid-Dec. 1995, some 85 +/- 7 days after perihelion,
with a relative deceleration of 7.6 +/- 0.4 units (of 10**-5 the
solar attraction) and with a submeter-per-second relative velocity.
Scenarios with E splitting off from B are unlikely. The failure to
detect E before the comet's 1996 conjunction with the sun was
caused by its subarcsec separation from C until late Mar. 1996,
when the comet already was < 20 deg from the sun. However, unless
too faint, E should have been detected in high-resolution images
taken in Aug.-Sept. 1996, when it was 8"-10" from C. Recent
offsets of component B from C are consistent with those reported in
1995-1996, suggesting that B separated from C on 1995 Nov. 11 +/- 4
with a relative deceleration of nearly 8 units and a relative
velocity of about 1.7 m/s. Predicted separation distances and
position angles for B and E relative to C (0h TT; p.a. are, within
1 deg, the same for both companions): 2000 Dec. 12, 580", 1600",
295 deg; Dec. 22, 624", 1730", 292 deg; 2001 Jan. 1, 656", 1830",
288 deg; Apr. 21, 271", 760", 245 deg; May 1, 240", 670", 244 deg;
May 11, 213", 590", 243 deg; May 21, 191", 530", 242 deg; May 31,
173", 470", 241 deg."
KS 1947+300
I. Negueruela, Observatoire de Strasbourg; A. Marco,
University of Alicante; R. Speziali and G. L. Israel, Osservatorio
di Roma, write: "On Dec. 1, we obtained a low-resolution spectrum
of the only blue star in the error circle of KS 1947+300 (IAUC
7523; Goranskij et al. 1991, Sov. Astron. Lett. 17, 938) with the
1.82-m telescope (+ AFOSC grism no. 4) at the Asiago Observatory.
The object displays relatively strong H-alpha emission (EW = 1.5
nm) and weak emission in H-beta. The spectrum is typical of a
moderately reddened OBe star in a Be/x-ray binary system, as
expected from the identification with GRO J1948+32 (IAUC 7531).
The spectral type is approximately B0. Infrared photometry was
carried out on Dec. 6 with the AZT-24 1.1-m telescope (+ SWIRCAM)
at Campo Imperatore, yielding the following magnitudes: J = 12.0
+/- 0.2, H = 11.5 +/- 0.1, K = 11.0 +/- 0.2 (suggesting the
presence of circumstellar emission). This is most likely the
optical counterpart to KS 1947+300."
(C) Copyright 2000 CBAT
2000 December 13 (7541) Daniel W. E. Green
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