Central Bureau for Astronomical Telegrams
IAUC 5470: N Oph 1991 No. 1; Mkn 421, PKS 0537-441, QSO 0716+714; 1992G
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Circular No. 5470
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
NOVA OPHIUCHI 1991 No. 1
M. A. Dopita, Mt. Stromlo Observatory; and L. Drissen, Space
Telescope Science Institute, communicate: "From a spectrogram
obtained on Mar. 9.77 UT using the Double Beam Spectrograph on the
2.3-m telescope at Siding Spring, operated by the Australian National
University, it is evident that Nova Oph 1991 No. 1 is another
member of the class that is rich in O, Ne, and Mg. The spectrum
shows [O III] 5007-nm and [Ne V] 3426-nm emission present at about 7
times the intensity of the H-beta line, and the [Ne III] 3686-nm
line is present at about 4 times the intensity of the H-beta line.
The [O III] (4363 nm)/(5007 nm) ratio indicates an electron density
of 5 x 10E5 cmE-3. The emission lines have a FWHM of about 1800
km/s. Considering that it is a year since outburst, this nova
remains unusually bright for its class and in this respect may
resemble QV Vul."
MARKARIAN 421, PKS 0537-441, QSO 0716+714
The Compton Observatory EGRET Team (P. F. Michelson, Y. C. Lin,
and P. L. Nolan, Stanford University; D. L. Bertsch, C. E. Fichtel,
R. C. Hartman, S. D. Hunter, P. W. Kwok, J. R. Mattox, P. Sreekumar,
and D. J. Thompson, Goddard Space Flight Center, NASA; D. A. Kniffen,
Hampden-Sydney College; G. Kanbach, H. A. Mayer-Hasselwander, C. von
Montigny, K. Pinkau, H. Rothermel, and M. Sommer, Max-Planck-Institut
fur Extraterrestrische Physik; and E. Schneid, Grumman Aerospace
Corporation) reports the tentative identifications of three BL Lac
objects as high-energy gamma-ray sources: Mrk 421, observed 1991
June 27-July 11; PKS 0537-441, observed 1991 July 26-Aug. 8; and QSO
0716+714, observed 1992 Jan. 10-23. All three sources have flux
values between 1 and 3 x 10E-7 photons cmE-2 sE-1 above 100 MeV. An
additional observation of PKS 0537-441 is planned for the period May
14-28, and an additional exposure to Mrk 421 is scheduled for Aug.
6-20.
SUPERNOVA 1992G IN NGC 3294
Visual magnitude estimates (cf. IAUC 5458): Feb. 25.95 UT,
13.5 (A. Mizser, Budapest, Hungary); 29.795, 13.9 (M. Tombelli,
Montelupo, Italy); Mar. 7.806, 14.0 (S. Korth, Dusseldorf, Germany).
1992 March 10 (5470) Daniel W. E. Green
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