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IAUC 4315: N Cen 1986; V822 Cen (CENTAURUS X-4); Corr

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                                                  Circular No. 4315
Central Bureau for Astronomical Telegrams
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
TWX 710-320-6842 ASTROGRAM CAM    Telephone 617-495-7244/7440/7444

     J. A. de Freitas Pacheco, University of Sao Paulo, telexes:
"SIT-Vidicon spectra of Nova Cen 1986 obtained on Jan. 7 and 8 reveal
a strong blue continuum and H emission lines, with H-alpha being by
far the most intense feature.  Low-ionization species such as O I,
Na I, and Fe II are also present with emission lines of moderate
intensity.  Higher-ionized atoms including Fe V, Fe VI, and Ca V
are also present.  The 'coronal' line 637.4 nm is clearly present
in the spectra, indicating quite different physical conditions in
the shell.  No He lines are visible in the data.  Coude spectra
obtained on Jan. 7 and 8 and more recently are now being reduced."
     J. Krautter and A. R. Walker, Cerro Tololo Interamerican
Observatory, report CCD photometry (accuracy about 0.05 mag) with B, V,
and Cousins R filters at the 0.91-m La Serena telescope on Feb. 6:
V = 14.83, B-V = +0.60, V-R = +1.21.
     Visual magnitude estimates (cf. IAUC 4298) by R. H. McNaught,
Coonabarabran, N.S.W. (all are approximate since they are well below
the comparison sequence, except for the first estimate):  Jan.
19.68 UT, 9.6; 28.74, 13.5; 29.77, 13.7; 30.76, 13.9; 31.76, 14.3;
Feb. 1.75, 14.4; 3.76, 15.0; 6.76, 15.6; 7.72, 15.6; 11.77, 15.6.

     A. P. Cowley, Arizona State University, and F. D. A. Hartwick,
University of Victoria, write:  "Optical observations of the x-ray
transient Cen X-4 obtained at Cerro Tololo Interamerican Observatory
on Jan. 23-27 show that the system has recently faded to its
pre-outburst brightness (mag about 19) as in Fig. 1a of Canizares et
al. (1980, Ap.J. 236, L55).  The spectrum shows a dK secondary and
very weak H-beta emission.  This contrasts with scattered observations
as recent as May 1986 which showed the magnitude near about 16.5 and a
spectrum dominated by a bright accretion disk with strong emission
lines of H, He I, He II, and Ca II.  A photometric period of about 15
hr was recently announced by Ilovaisky et al. (IAUC 4264)."

IAUC 4312, "Periodic Comet Schwassmann-Wachmann 2 (1986h)".  In
   line 1,  for  Merlin (0.40-m reflector)  read  J.-C. Merlin
   (Le Creusot, France, 0.40-m reflector).

1987 February 18               (4315)            Daniel W. E. Green

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