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IAUC 2870: X-RAY SOURCES; 1975o; V373 Sct (N Sct 1975)

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IAUC number 

                                                  Circular No. 2870
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Cable Address: SATELLITES, NEWYORK
Western Union: RAPID SATELLITE CAMBMASS


X-RAY SOURCES
     N. E. White, H. E. Huckle, K. O. Mason, P. A. Charles, G.
Pollard, J. L. Culhane and P. W. Sanford, Mullard Space Science
Laboratory, write: "The Copernicus and Ariel 5 (experiment C) satellites
have made observations of seven galactic x-ray sources in the
energy range 3-8 keV.  The results of a search for modulation of
the x-ray flux in the period range 2.5-50 min are as follows:

   Source      Satellite   Date           C     Period (min)    A
   3U 1223-62  Ariel       1975 Jan.  5   39  11.64  +/- 0.02   50
   3U 1728-24  Copernicus  1972 Sept.11   47   4.315 +/- 0.004  12
   3U 1728-24    "         1973 Mar. 25   31   4.39  +/- 0.07   20
   3U 1813-14    "         1975 Aug.  1  254  31.9   +/- 0.1     4

C gives the mean count per min.  The amplitude A (percent) quoted
is the peak to mean amplitude as a percentage of the mean flux.
Four sources, 3U 1702-36, 1728-16, 1757-25 and 1811-17, showed no
detectable modulation with upper limits to the amplitude, of 15, 5,
4 and 4 percent, respectively, when observed with Copernicus.  The
4.3-min period of 3U 1728-24 is close to twice the 2.3-min period
suggested by Lewin et al. (1971, Astrophys. J. 169, L17) from
higher energy data."


PERIODIC COMET GEHRELS 3 (1975o)
     The following precise positions have been obtained by J. H.
Bulger and R. E. McCrosky with the 155-cm reflector at Harvard
Observatory's Agassiz Station.  Measurer: C. Y. Shao.  The Nov. 7 and
9 positions are re-reductions of those given on IAUC 2865.

     1975 UT             R. A. (1950) Decl.        m1    Observer
     Nov.  7.16956     1 44 48.10   +11 37 30.3   18     Bulger
           9.15630     1 43 38.38   +11 30 28.6          McCrosky
          10.10184     1 43 06.05   +11 27 11.7            "


V373 SCUTI (NOVA SCUTI 1975)
     Further selected visual magnitude estimates: Oct. 12.8, 10.6 (R.
Lukas, Wilhelm Foerster Observatory); 22.1, 10.9 (L. C. Peltier,
Delphos, Ohio); 25.99, 10.9 (P. Garnavich, Bowie, Maryland); 28.1,
11.4 (Peltier); 31.8, 10.8 (Lukas); Nov. 1.00, 11.0 (Garnavich).


1975 November 21               (2870)              Brian G. Marsden

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