Central Bureau for Astronomical Telegrams
IAUC 5431: 3C 279; 4C 38.41, PKS 0528+134, PKS 0208-512; 1992A
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Read IAUC 5432
Circular No. 5431
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
3C 279
The Compton Observatory/EGRET Team (G. Kanbach, H. A. Mayer-
Hasselwander, C. von Montigny, K. Pinkau, H. Rothermel, and M.
Sommer, Max-Planck-Institut fur Extraterrestrische Physik; D. L.
Bertsch, C. E. Fichtel, R. C. Hartman, S. D. Hunter, D. A. Kniffen,
P. W. Kwok, J. R. Mattox, P. Sreekumar, and D. J. Thompson, Goddard
Space Flight Center, NASA; Y. C. Lin, P. F. Michelson, and P. L.
Nolan, Stanford University; and E. Schneid, Grumman Aerospace
Corporation) communicates: "The high-energy gamma-ray flux from 3C 279
was observed to be (8 +/- 1) x 10E-7 cmE-2 sE-1 (energy > 100 MeV)
during the period 1991 Oct. 3-17, 30 percent of the flux observed in
the period June 15-28 (IAUC 5311). Also, further analysis of the
1991 June observation indicates highly significant time variation of
the 3C 279 flux during the 2-week period (chance of being random
10E-9). After a gradual increase, the flux peaked on June 25 and
then sharply decreased over the following three days it was observed.
We note that EGRET will be pointed 34 deg from 3C 379 during the
period 1992 Apr. 16-30. At this angle, the EGRET sensitive area is
down by an order of magnitude, but if the flux level is similar to
that in June, then some sensitivity to time variations remains.
Simultaneous radio and optical observations might be of great value."
4C 38.41, PKS 0528+134, PKS 0208-512
The Compton Observatory/EGRET Team also reports: "EGRET data
analysis reveals highly significant detections of gamma-ray flux
(energy > 100 MeV) for three radio-loud, flat-spectrum sources.
Following are the tentative identification (catalogue designation),
observation dates (1991), and most probable position (galactic
coordinates in degrees, system II) with a 63-percent confidence region:
4C 38.41, Sept. 12-19, l = 61.0 +/- 0.3, b = 42.30 +/- 0.16; PKS
0528+134, Apr. 22-May 30, l = 191.34 +/- 0.15, b = -10.95 +/- 0.10;
PKS 0208-512, Sept. 19-Oct. 3, l = 276.16 +/- 0.25, b = -61.99 +/-
0.13."
SUPERNOVA 1992A IN NGC 1380
W. Liller, Vina del Mar, Chile, revises his magnitude estimate
on Jan. 11.15 UT to 13.7 (cf. IAUC 5428); further unfiltered magnitudes
measured with a 0.20-m Schmidt (+ SBIG ST-4 CCD; comparison V
data from NGC 1326 sequence by R. Buta): Jan. 12.1, 13.56; 14.1,
13.24; 15.1, 13.40.
1992 January 15 (5431) Daniel W. E. Green
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