Central Bureau for Astronomical Telegrams
IAUC 4081: EXO 063111+1801.9; FAIRALL 9
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Circular No. 4081
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
EXO 063111+1801.9
G. F. Bignami, P. A. Caraveo and L. Salotti, Institute of
Cosmic Physics, Milan; and G. G. C. Palumbo, National Research
Council, Bologna, telex: "The EXOSAT channel-multiplier array position
of the source EXO 063111+1801.9 is R.A. = 6h31m11s49, Decl. = +18deg01'52"5
(equinox 1950.0), and the 0.5-2-keV flux is a few times 10**-16 J m**-2
s**-1. The source had been serendipitously discovered in an Einstein
image-proportional-counter field and suggested to have a soft
spectrum, but there was no possibililty of high-resolution-imager
follow up. The improved position allows us to propose a tentative
optical counterpart R.A. = 6h31m10s82, Decl. = +18deg01'54"2 (equinox
1950.0), some 10" away. The object appears stellar on the Palomar
Sky Survey at V ~ 17, implying comparable optical and x-ray
luminosity. No radio counterpart is seen in the 21-cm Westerbork map
of Spoelstra and Hermsen (1984, A.Ap. 135, 135), or in the 6-cm
and 20-cm Bonn maps of Sieber and Schlikeiser (1982, A.Ap. 113,
314). Accurate spectrophotometry of the object is needed."
FAIRALL 9
W. Wamsteker, R. Gilmozzi and J. Clavel, European Space
Agency, Madrid, report: "Recent observations with the International
Ultraviolet Explorer of the Seyfert-I galaxy Fairall 9 = ESO
113-IG45 indicate that the extended decrease in ultraviolet
brightness (by ~ 3.5 mag at 135 nm between 1978 and 1984) may have
come to an end. Observations made with IUE on 1985 May 1 at low
resolution give fluxes at 135 and 257 nm of ~ 2.0 and ~ 1.6 x
10**-16 J s**-1 m**-2 nm**-1, respectively, an increase of ~ 1 mag with
respect to the observations made by Ulrich et al. in 1984 Oct. A
spectrum taken on 1985 June 13 in the 200-300-nm range confirms
the earlier results and shows that the brightness increase is
still continuing. The continuum variations are accompanied by
similar variations in the emission-line strength in L-alpha, C IV, Si
IV and possibly also in Mg II. Since it is quite possible that
these results represent the start of an extended phase of
brightening of the nucleus of Fairall 9, additional observations at
different wavelengths would be very important. The next
ultraviolet and x-ray observations are planned for July 25."
1985 July 17 (4081) Brian G. Marsden
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