Subject: IAUC 6865: XTE J0421+560, CI Cam; GRB 980329; 1998S
From: quai@cbatmpc (IAUC mailing list)

Circular No. 6865
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XTE J0421+560 AND CI CAMELOPARDALIS
     M. R. Garcia, P. Berlind, E. Barton, and J. E. McClintock,
Harvard-Smithsonian Center for Astrophysics; and P. J. Callanan and
J. McCarthy, University College, Cork, report:  "Photometric and
spectroscopic observations of CI Cam, the possible counterpart of
XTE J0421+56 (IAUC 6855, 6857), were obtained with the 1.2-m and
1.5-m telescopes at the Whipple Observatory during Apr. 3.08-3.17
UT.  Conditions were photometric, with variable 2" seeing.  We find
V = 9.25 +/- 0.1, B = 10.25 +/- 0.1.  This implies a brightening of
> 2 mag in each band, relative to the levels measured by Bergner et
al. (1995, A.Ap. Suppl. 112, 221).  Relative photometry of three B
and four V frames yields an upper limit to any short-term
photometric variability of < 2 percent during our observations.
Our spectra (range 400-700 and 600-700 nm; resolution 0.3 and 0.075
nm), appear similar to those of Downes (1984, PASP 96, 807), but
the level of Fe II and He I emission has strengthened in comparison
to H Balmer.  He II (468.53 nm) and He I (471.29 nm) are detected
with equivalent widths of 1.5 +/- 0.5 and 3.0 +/- 1.0 nm,
respectively, confirming the new He II emission reported by Wagner
et al. (IAUC 6857).  The forest of strong H, He I, and Fe II
emission lines obscures the continuum to the extent that it is
unclear if any photospheric absorption lines are present.  None of
the lines in our spectra shows any evidence for the type of double-
peaked emission typically arising in x-ray-binary or cataclysmic-
variable accretion disks.  Our data are consistent with the
association of CI Cam with XTE J0421+56, but imply that this might
then be an unusual symbiotic-type x-ray binary, perhaps akin to GX
1+4 or 2A 1704+241 (= HD154791)."

                      (C) Copyright 1998 CBAT
1998 April 6                   (6865)            Daniel W. E. Green