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IAUC 6222: GRO J1735-27 AND GRO J1750-27; 1995Y; 1995Z

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                                                  Circular No. 6222
Central Bureau for Astronomical Telegrams
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
Phone 617-495-7244/7440/7444 (for emergency use only)

GRO J1735-27 AND GRO J1750-27
     T. Koh, D. Chakrabarty, T. A. Prince, and B. Vaughan,
California Institute of Technology; and S. N. Zhang, M. Scott, M.
H. Finger, and R. B. Wilson, Marshall Space Flight Center, report
for the Compton GRO/BATSE team:  "Further observations of the
recently-discovered, 4.45-s transient hard x-ray pulsar in the
Galactic center region (GRO J1735-27; see IAUC 6207) have yielded a
refined position, based only on pulsed flux, which indicates that
the pulsed and unpulsed emission reported on IAUC 6207 come from
different sources.  The estimated 90-percent-confidence error box
for the pulsed source is approximately a quadrilateral of size 0.7
deg**2, with vertices R.A. = 17h47m, Decl. = -27o.8; 17h50m,
-28o.0; 17h52m, -26o.9; 17h49m, -26o.7 (equinox 2000.0).  In
accordance with the new position, we have designated the pulsed
source as GRO J1750-27, the previous designation (GRO J1735-27)
referring to the unpulsed source.  The pulsed emission from GRO
J1750-27, first detected on July 29 UT, continues to be visible as
of Aug. 29; its barycentric pulse period on Aug. 29.5 was 4.45311
+/- 0.00003 s, with a period derivative of about -0.11 s/yr.
Optical and soft-x-ray observations of the error box are encouraged
to constrain further the source position and to identify the
accreting companion.  The unpulsed source (GRO J1735-27) is not
observed in data combined during Aug. 11-21, while pulses from GRO
J1750-27 have been detected at a nearly constant level through Aug.
29.  The position reported on IAUC 6207 remains valid for the
unpulsed source GRO J1735-27."

     M. Cavagna, Sormano, Italy, reports the following precise
position for SN 1995Y (cf. IAUC 6221) from a CCD image obtained on
Sept. 1.945 UT, when the supernova was at V = 18:  R.A. =
1h10m59s.60, Decl. = +33o08'40".7 (equinox 2000.0; GSC reference
stars); this corresponds to a point 8".4 east and 26".1 south of
the galaxy's center.  M. Tombelli, Montelupo, Italy, reports the
following position end figures from a CCD image obtained on Sept.
3.063: 59s.70, 42".8 (also GSC reference stars).

     Cavagna also sends the following precise position of SN 1995Z
from a CCD image obtained on Sept. 1.954 UT:  R.A. = 1h23m38s.35,
Decl. = +32o37'53".1 (equinox 2000.0; magnitude V = 19).

1995 September 6               (6222)            Daniel W. E. Green

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