Central Bureau for Astronomical Telegrams
IAUC 4556: S Per; BLAZARS IN 3C 279 AND 3C 273; 1987s
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Circular No. 4556
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
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
S PERSEI
R. E. Stencel, Center for Astrophysics and Space Astronomy,
University of Colorado, writes that this red supergiant variable
and maser source has brightened by 1.5 mag in the past two months,
after many months near visual mag 11, as indicated by the following
visual magnitude estimates reported to D. Street and Stencel, who
have been coordinating a monitoring campaign: 1987 Nov. 9, 10.7
(R. Keen, Mt. Thorodin, CO); Nov. 25, 10.8 (J. Sapp, Boulder, CO);
1988 Feb. 13, 9.2 (Sapp); Feb. 22, 9.2 (Keen). A similar rapid
rise was observed in late 1981, when the star brightened from 11.5
to 8.5 in 150 days. Spectroscopic observations are encouraged.
BLAZARS IN 3C 279 AND 3C 273
E. I. Robson, Lancashire Polytechnic, Preston; and M. G.
Smith, J. Aycock, and D. M. Walther, Joint Astronomy Centre, Hilo,
telex: "Our multifrequency monitoring program has revealed two
blazars now undergoing flaring. A major flare has just occurred in
3C 279, as the infrared fluxes have increased by an average factor
of 17 from their 1987 May values along with a flattening of the
infrared spectrum as predicted by our models. JHKLMNQ (1.25-20 ;m)
data obtained at the U.K. Infrared Telescope on 1988 Feb. 23 reveal
a spectral slope of index -1.28 and K flux of 81 mJy (K = 9.7).
The fluxes were 40 percent higher on Jan. 30. Although the flux is
now in decline, monitoring at all wavelengths is vital for modelling.
After two years of relative inactivity, 3C 273 is also in a
high state; flux increases in the infrared of 46 percent have
occurred during the first two months of 1988. Nightly variations are
evident and monitoring at all wavelengths is urged, particularly at
mid-infrared (M, N) wavelengths during the decline of the source to
its quiescent state."
COMET BRADFIELD (1987s)
Total visual magnitude estimates (B = binoculars): Feb. 4.76
UT, 8.5 (S. Korth, Monheim, W. Germany, 15x80 B); 8.17, 8.0 (C. S.
Morris, Whitaker Peak, CA, 20x80 B; 2 deg 10' tail in p.a. 69 deg); 9.78,
8.4 (R. Haver, Rome, Italy, 15x80 B; 42' tail in p.a. 55 deg); 12.79,
8.6 (A. Boattini, Florence, Italy, 0.33-m reflector; 28' tail in
p.a. 57 deg); 14.16, 7.9 (A. Hale, Las Cruces, NM, 10x50 B); 16.16,
8.1 (Morris); 21.19, 8.3 (Hale, 0.41-m reflector).
1988 February 26 (4556) Daniel W. E. Green
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