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IAUC 3855: 1983k; AG Dra

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IAUC number 

                                                  Circular No. 3855
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 617-864-5758


COMET IRAS (1983k)
     The following precise positions have been measured by P. M.
Kilmartin from plates taken by A. C. Gilmore with the 0.6-m f/14
reflector at Mt. John University Observatory:

         1983 UT             R.A.     (1950.0)    Decl.

         Aug. 10.34225      12 13 24.26      -36 10 36.7
              10.37237      12 13 25.38      -36 10 07.0

     Parabolic elements determined by the undersigned from the
five available accurate positions July 14, 19 and Aug. 10:

          T = 1983 May 2.661 ET  Peri. = 265.554
                                 Node  = 171.091   1950.0
          q =   2.41759 AU       Incl. = 138.845

     1983 ET     R.A. (1950.0) Decl.      p        r       m1
     Aug. 14    12 15.76    -35 10.6    2.964    2.670    18.6
          24    12 22.35    -32 53.0
     Sept. 3    12 29.08    -31 07.6    3.364    2.768    19.1
          13    12 35.83    -29 47.4
          23    12 42.47    -28 46.9    3.688    2.877    19.4


AG DRACONIS
     R. Viotti, Istituto Astrofisica Spaziale, Frascati; C. Eiroa,
Max-Planck-Institut fur Astronomie, Heidelberg; A. Cassatella,
European Space Agency, Villafranca; and A. Altamore, Istituto
Astronomico, La Sapienza University, Rome, report: "After the active
phase started in 1980, the Population II symbiotic star AG Dra has
reached a minimum in mid-1983.  Coordinated ultraviolet (made with
IUE at Vilspa) and infrared (2.2-m Calar Alto telescope) observations
indicate that the ultraviolet continuum and line fluxes have
largely weakened in June and are close to the pre-outburst values.
The equivalent width of He II 164-nm is much stronger than at
maximum, suggesting a higher temperature for the hot source.  A
small, probably irregular, variability in JHK and perhaps also the
L band was noted during 1981-1983 but is not correlated with the
ultraviolet variations.  This confirms the presence of large-
amplitude variability of the hot radiation source, while the cool
star is more stable, as was also noted in Z And (cf. IAUC 3750)."


1983 August 29                 (3855)              Brian G. Marsden

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