Compton Observatory Science Report #120
Thursday, May 20, 1993 
Eric Chipman, Compton Observatory Science Support Center

Questions or comments can be sent to the Compton SSC.  Phone 301/286-7764,
e-mail SPAN GROSSC::CHIPMAN, Internet chipman@grossc.gsfc.nasa.gov.  

The Compton spacecraft continues normal operations.  There were
no maneuvers scheduled this week.

It has been decided to change the date of the next maneuver, to
move it forward by 1 day to Monday, May 24.  This will permit a
simultaneous observation of NGC 4151 by GRO, ASCA and ROSAT early
on the 25th.

BATSE
-----
No report received this week.

COMPTEL
------- 
The COMPTEL experiment is performing well and continues routine
observations.

Two solar flare triggers were received from the BATSE experiment
over the past week, while the Sun has been within the field of
view of the telescope. Neither appears to have been a strong
emitter of MeV gamma rays.

EGRET
-----
EGRET operations were normal this week.  The EGRET results on
AGN's and their implications for the extragalactic diffuse
radiation received considerable attention at the 
Extragalactic Diffuse Symposium held at the Space Telescope
Science Institute in honor of Riccardo Giacconi this week.
Now that the lengthy full primary analysis of the Phase 1
data is essentially complete, we shall begin the detailed
analysis and study of and hope to have results on the diffuse
radiation by the time of the Second Compton Symposium.  As
an interesting sidelight, a gamma ray whose estimated energy
is 85 GeV has been seen.

OSSE
----
OSSE operations are normal.

For viewing period 221, the Z-axis target is the Crab Nebula and pulsar
(PI team) and the X-axis targets are 2CG135+01 (PI team) and the radio
pulsar PSR 1951+32 (PI team).  The slewing response to BATSE solar triggers
is disabled.

OSSE papers on PSR 1509-58 (Ulmer et al.) and annihilation radiation from the
Galactic Center region (Purcell et al.) have been accepted for publication
in the Astrophysical Journal.

Data from viewing period 8 have been delivered to the GRO Science Support
Center Archive.  Targets during this period were the Vela pulsar, Vela X-1,
SN 1991T, and 3C273.