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IAUC 4096: 1985N; BR Cir; EXO 2030+375

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                                                  Circular No. 4096
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

     A. Gautschy and R. Singer report the discovery with the 1-m
telescope at Las Campanas Observatory of a probable supernova in
an anonymous galaxy at R.A. = 21h52m5, Decl. = -55deg28'1 (equinox 1985.75).
The supernova, 14"5 east of the nucleus and of mag ~ 18, was
discovered on Aug. 21 and confirmed on Aug. 22.

     A. F. Tennant and R. A. Shafer, Institute of Astronomy,
Cambridge, report that an EXOSAT observation of BR Cir = Cir X-1 was
made during July 27.87-28.92 UT.  During July 28.25-28.42 the
source exhibited an extreme high-state flux, at times exceeding 3
Crab; the onset of this state occurred within an hour of the
predicted start of the radio flare, following the formula JD
2444618.23 +/- (16.5696-0.0000489E)E.

     G. D. Nicolson, Hartebesthoek Radio Astronomy Observatory,
Johannesburg, communicates: "Regular observations at 6 cm have
been made of BR Cir.  After an extended low state from 1981 Sept.
until 1984 July a weak 0.3-Jy flare was observed, indicating a
possible return to the high state.  Though there were no further
flares in 1984, there have been four flares of between 0.2 and 0.4
Jy in 1985.  BR Cir was below our horizon during the above EXOSAT
observations of an extreme high state.  When the source rose it
was at 0.2 Jy and fluctuated between this level and 0.07 Jy during
July 28.479-28.938 UT.  By the next day the flux had returned to
the quiescent zero level."

EXO 2030+375
     M. J. Coe and C. G. Hanson, Southampton University; and A. J.
Longmore, Royal Observatory, Edinburgh, report that infrared
observations from the 3.8-m U.K. Infrared Telescope of the error box
for this source (IAUC 4066) reveal two possible counterparts: one
at R.A. = 20h30m20s5, Decl. = +37deg27'42"6 (equinox 1950.0, uncertainty
2"), with magnitudes J = 15.07, H = 14.43, K = 14.30; and one at
R.A. = 20h30m22s1, Decl. = +37deg28'00"0, with magnitudes J = 11.87, H =
10.63, K = 9.75.  The first candidate is the brightest optical
source suggested by Robin et al. (IAUC 4073).  In addition, the
infrared/optical luminosity of the first candidate is similar to
that of V0332+53, another x-ray pulsator.

1985 August 26                 (4096)              Brian G. Marsden

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