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IAUC 3993: 1984p; OH MEGAMASERS; N Vul 1984

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IAUC number 

                                                  Circular No. 3993
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


PERIODIC COMET TSUCHINSHAN 1 (1984p)
     This comet has been recovered as shown below.  The indicated
correction to the prediction on MPC 8805 (elements on MPC 7658) is
very small.

   1984 UT          R.A.   (1950.0)   Decl.     m2    Observer

   Sept. 4.75972    5 33 09.4    +15 44 20     20.5   Seki
         5.49932    5 34 49.14   +15 46 11.4   20.5   Gibson
         6.50210    5 37 04.98   +15 48 43.1            "

T. Seki (Geisei).  0.60-m reflector.  Single observation.
J. Gibson (Palomar).  1.2-m Schmidt.  Mediocre seeing; weak image
   near plate limit.


OH MEGAMASERS
     W. A. Baan, A. D. Haschick and J. T. Schmelz write: "Recent
observations at the 91-m telescope of the National Radio Astronomy
Observatory resulted in the detection of three new powerful OH
masers in the disturbed galaxies NGC 3690, Mrk 231 and Arp 238.
The maser in Mrk 231 has an isotropic luminosity of 2500 LO if the
galaxy is at 227 Mpc.  This makes it 3.5 times more luminous in
the 1667-MHz OH-maser line than the megamaser source IC 4553 (=
Arp 220; Baan and Haschick 1984, Ap.J. 279, 541).  NGC 3690 (56
Mpc) and Arp 238 (170 Mpc) have isotropic luminosities of 85 LO and
290 LO, respectively.  Almost all extragalactic OH and H2O megamaser
sources can be interpreted with a maser amplification model
where inverted foreground molecular gas in an edge-on disk amplifies
the central continuum source.  The infrared radiation field is
likely to be the cause of the population inversion of the OH and
H2O needed for these molecular image-processing systems."


NOVA VULPECULAE 1984
     Further visual magnitude estimates: Sept. 10.92 UT, 8.6 (P.
Vedrenne, Paris, France); 12.05, 8.5 (P. Maley, Houston, TX);
13.81, 8.6 (E. Schweitzer, Strasbourg, France); 15.12, 8.6 (
Maley); 16.08, 8.6 (Maley): 17.05, 8.3 (Maley); 18.03, 8.3 (J.
DeYoung, Alexandria, VA); 19.02, 8.1 (DeYoung); 20.07, 7.8 (Maley);
22.06, 8.6 (Maley); 23.04, 8.8 (Maley); 24.04, 9.2 (Maley).


1984 September 26              (3993)              Brian G. Marsden

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