Central Bureau for Astronomical Telegrams
IAUC 4876: GT 0116+622; 1989r
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Read IAUC 4877
Circular No. 4876
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
GT 0116+622
B. Margon and A. Phillips, University of Washington; and
G. Jacoby and R. Ciardullo, Kitt Peak National Observatory, write:
"We have identified a near-infrared bright counterpart to the
highly-variable, unresolved galactic plane radio source
GT 0116+622 (Duric and Gregory 1988, A.J. 95, 1149). This source
is of particular interest, as it has been suggested (Gregory et al.
1986, Nature, 323, 602) to be the counterpart of the gamma-ray
source Cas gamma-1. The object, observed on six nights at
Kitt Peak in 1989 September, is located at R.A. = 1h16m01s.24,
Decl. = +62 13'29".7 (equinox 1950.0; estimated uncertainties of
< 0".5 in each coordinate); this is in good agreement with the
radio position (0".3 uncertainty). The counterpart has K = 15.1,
J-K = +1.2, although the absolute photometric calibration is
still preliminary. It also appears on R-band CCD images at
R about 20.5 +/- 0.5. Differential photometry with field stars
indicates that there is no J-band variability in observations made
on multiple consecutive nights, to upper limits of +/- 0.1 mag;
this may be significant, as the radio source is reported to be
highly variable on a timescale of days. All of the images show
the object to be spatially extended: the K-band angular size is
3" FWHM. One cannot yet distinguish between a galactic or
extragalactic nature for this unusual object. However, if the
assumption is made that the observed angular diameter of the
images corresponds to a typical galaxian dimension of 5-10 kpc,
then the implied distance is several hundred Mpc, and the inferred
red/infrared luminosity is compatible with that of a galaxy.
If this argument proves valid, the previously suggested
identification with the gamma-ray source would seem unlikely."
COMET OKAZAKI-LEVY-RUDENKO (1989r)
Total visual magnitude estimates (cf. IAUC 4869): Oct. 2.75
UT, 8.0 (A. Boattini, Florence, Italy, 0.33-m reflector); 3.13,
8.0 (A. Hale, Las Cruces, NM, 10x50 binoculars); 3.78, 7.8 (M.
Verdenet, Bourbon-Lancy, France, 0.36-m reflector); 5.00, 7.8
(J. E. Bortle, Stormville, NY, 20x80 binoculars); 5.82, 7.5
(J.-C. Merlin, Le Creusot, France, 7x50 binoculars); 7.09, 7.7
(G. Kronk, Troy, IL, 20x80 binoculars); 8.12, 7.9 (C. S. Morris,
Pine Mountain Club, CA, 20x80 binoculars); 8.83, 7.8 (A. Pereira,
Cabo da Roca, Portugal, 0.15-m reflector); 9.76, 7.5 (S. Baroni,
Milan, Italy, 20x80 binoculars); 11.99, 7.8 (D. W. E. Green,
Cambridge, MA, 0.20-m reflector).
1989 October 13 (4876) Daniel W. E. Green
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