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IAUC 4221: KUWANO'S OBJECT IN Aql; GX 9+9; N Vul 1984 No. 2

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                                                  Circular No. 4221
Central Bureau for Astronomical Telegrams
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

     On May 18 Y. Kozai, Tokyo Astronomical Observatory, reported
that Yoshiyuki Kuwano had found on two Tri-X films exposed on May
12 what appears to be a previously unknown red variable star with
a large range in brightness.  R. H. McNaught, Siding Spring
Observatory, has identified the object on several photographic
surveys going back to 1951 and has measured the position from a J
film copy obtained with the U.K. Schmidt: R.A. =  19h54m31s44, Decl. =
-11deg22'22"1 (equinox 1950.0, uncertainty +/- 0"4).  Magnitude
estimates (mv or mpv unless otherwise stated) are as follows: 1951
Sept. 21, B = 16.7, R = 13.0 (Palomar Sky Survey); 1968 July 30, B
] 14 (Atlas Stellarum); 1973 July 4, 12 (Papadopolous atlas); 1982
Aug. 14, 14.7 (UKSTU J plate); 1984 Aug. 23, R = 12 (UKSTU); 1986
Mar. 9.7, [13 (Kuwano); 10.8, 13 (McNaught, 2415 film); May 9.8,
8: (McNaught, 2415 film, at limit of several exposures); 12.70,
9.0 (Kuwano); 17.7, ~ 8.9 (Kuwano); 20.64, 9.7 (McNaught); 21.69,
9.4 (McNaught).  McNaught also reports that P. Payne and J. W. V.
Storey, University of New South Wales, obtained an infrared spectrum
(range 2.0-2.5 micron) using the Anglo-Australian Telescope on
May 20; it shows a star of late spectral type with CO absorption.

GX 9+9
     P. Hertz and K. S. Wood, Naval Research Laboratory, write:
"We have discovered an x-ray periodicity of 4.20 + 0.06 hr in the
galactic-bulge source GX 9+9 = 4U 1728-16.  Data were obtained
with the HEAO A-1 scan modules and consist of 74 unevenly-spaced
observations during 1977 Sept. 13-18.  A phase histogram at the
best period appears approximately sinusoidal with peak-to-peak
modulation ~ 10 percent of the 175 ufu source flux.  A nearly
constant variation in flux is seen at all phases, and there is no
evidence for eclipses or dips.  The probability that the periodicity
is not real is < 0.6 percent.  Because of this unusual character,
confirmation in other x-ray data is desirable.  Searches
for the 4.2-hr periodicity in the proposed optical counterpart
(Davidsen et al. 1976, Ap.J. 203, 448) are suggested.

     Visual magnitude estimates by E. Schweitzer, Strasbourg,
France: May 13.14 UT, 10.6.

1986 May 27                    (4221)              Brian G. Marsden

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