Central Bureau for Astronomical Telegrams
IAUC 4789: BF Cyg; 1989 JA
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Circular No. 4789
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
BF CYGNI
A. Cassatella and R. Gonzalez-Riestra, IUE ESA Observatory,
Madrid; and H. M. Schmid, Institute of Astronomy, Zurich, report optical
and ultraviolet observations of the symbiotic star BF Cyg during its
present activity phase following the ultraviolet minimum in April. The
visual magnitude, as obtained from the fine-error sensor on board IUE,
was 10.3 on May 27.15 UT, compared to 11.5 on Mar. 14, the date of the
previous IUE observations. The level of the continuum around 130 nm
remained unchanged on the two dates and is typical of the phases when
the object is at minimum (with the cool star in front) in the far
ultraviolet. On the other hand, the continuum around 300 nm has
increased by a factor of two with respect to March. The emission
lines seen in the short-wavelength range are O I 130.5 nm, Fe II (UV
191) 178.5 nm, C III] 190.9 nm and a feature around 164 nm that is
probably due to O I]. The strong high-excitation lines of N V, C IV
and Si IV have disappeared. The long-wavelength range is dominated by
strong emission bumps tentatively ascribed to Fe II blends. Optical
spectra obtained with the 1.93-m telescope of the Observatoire de Haute
Provence in the range 455-505 nm on May 22 reveal a strong emission at
H beta, together with fainter (less than 0.1 the strength of H beta)
emissions from He I (471.8, 492.2 and 501.6 nm), [O III] (495.9 and
500.7 nm) and Fe II (458.4, 462.9, 492.4 and 501.8 nm) superimposed
on an F-type absorption spectrum. The linewidth (FWHM) of H beta is
less than 300 km/s.
1989 JA
D. I. Olsson-Steel, University of Adelaide, reports: "Although
comparison of the orbit and theoretical meteor radiant (R.A. = 237
deg, Decl. = +24 deg, Vgeo = 17.6 km/s, L sun = 65 deg; 1989 May 26;
equinox 1950.0) of 1989 JA does not show any correlation with the
well-known meteoroid streams, a direct search through the 2401 Harvard
photographic meteors (McCrosky and Posen 1961, Smithson. Contrib. Ap.
4, 15) indicates 13 correlated meteors using the standard orbital
discriminant test (D < 0.20) and more than twice as many using the
Drummond criterion. The form of analysis introduced by Olsson-Steel
(1988, Icarus 75, 64) shows a distinct peak for these data at the
nodal longitude of 1989 JA, strongly suggesting an associated stream."
1989 June 2 (4789) Brian G. Marsden
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