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IAUC 4980: 1990b; MWC 560

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                                                  Circular No. 4980
Central Bureau for Astronomical Telegrams
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

     K. Churyumov, Kiev Observatory, telexes the discovery of a new
comet by Kazimieras Cernis.  H. Kosai, National Astronomical Observatory
of Japan, reports independent discoveries by Tsuruhiko Kiuchi
and Yuji Nakamura.  The comet generally appears diffuse with some
condensation, coma diameter about 2'.  The following observations
are available:

     1990 UT           R.A. (1950) Decl.        m1       Observer
     Mar. 14.79        0 54.4      +43 04       9        Cernis
          16.441       1 03.0      +44 05       9        Kiuchi
          16.441       1 03.2      +44 07       9        Nakamura
          17.120       1 06.8      +44 31       8.4      Hale

K. Cernis (Vilnius).  0.12-m refractor.
T. Kiuchi (Usuda-machi, Nagano).  25x150 binoculars.
Y. Nakamura (Yokkaichi, Mie).  20x120 binoculars.
A. Hale (Las Cruces, NM).  0.41-m reflector.  Magnitude estimate
  with 10x50 binoculars.

MWC 560
     D. A. H. Buckley, Department of Astronomy, University of Cape
Town; and D. Laney, T. Lloyd Evans, and F. van Wyk, South African
Astronomical Observatory, report additional observations of MWC 560
(cf. IAUC 4955, 4969, 4976, 4978, 4979) made at SAAO.  The star
brightened from V = 9.64 on Feb. 28 to V = 9.54 on Mar. 11.  Infrared
photometry on Mar. 7 and 10 gave J = 6.42, H = 5.44, K = 5.11,
and L = 4.78, which are unchanged from the mean values of 1984-1986,
and indicate that the M4 star is still the main source of light in
the infrared.  The 615.9-nm bandhead of TiO is marginally present
in spectra taken on Mar. 10 and 11.  A spectrum on Mar. 2 (in the
region 330-550 nm) showed emission lines of H-beta and H-gamma, and
broad, deep Balmer absorption at velocities of up to -5000 km/s and
FWHM of about 2000 km/s.  Two broad absorption components at -4800
and -4000 km/s, seen on Mar. 9, had disappeared almost completely on
Mar. 10, while absorption at -350 km/s strengthened from Mar. 10 to
11.  High-speed photometry on Mar. 12 over about 2 hr showed
variations of order 5 percent with a timescale of about 20 min.

1990 March 17                  (4980)             Daniel W. E. Green

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