The Compton Gamma-Ray Observatory (CGRO) was the second of NASA's Great
Observatories. It was launched on April 5, 1991, from Space Shuttle Atlantis.
It operated sucessfully for 9 years, and then was safely de-orbited and
re-entered the Earth's atmosphere on June 4, 2000.
Compton had four instruments that covered an unprecedented six decades of the
electromagnetic spectrum, from 30 keV to 30 GeV. In order of increasing
spectral energy coverage, these instruments were the Burst And Transient
Source Experiment (BATSE), the Oriented Scintillation Spectrometer Experiment
(OSSE), the Imaging Compton Telescope (CompTel), and the Energetic Gamma Ray
Experiment Telescope (EGRET). BATSE viewed the full sky, as a transient
monitor and is thus not included in this database table of pointed telescope
observations. Also, EGRET and CompTel had wide fields of view, about 30
degrees, and, as such, viewed multiple targets per X-axis pointing. OSSE
could be slewed (about one axis) independently from the spacecraft, so it
typically viewed 2 targets per spacecraft Z-axis orientation, or "viewing
period." Viewing periods were typically two weeks long.
This database table contains the CGRO observations for Cycles 1 through 9.
The Cycle 1 observations for EGRET and COMPTEL were part of the All-Sky
Survey with no defined targets.
The Compton Observator Science Support Center observation timelines are
available at http://cossc.gsfc.nasa.gov/docs/cgro/timeline/.
This database table was last updated in November 2001. The information
contained therein was provided by the Compton Observatory Science Support
Center (COSSC). Galactic coordinates were added to the table by the HEASARC
in August 2005.
The proposal phase/cycle number.
The viewing period of the observation.
The start date of the viewing period.
The end date of the viewing period.
The unique proposal number from which the observation was derived.
The last name of the Principal Investigator of the observation or
the instrument team.
The instrument(s) used for the observation, where O = OSSE,
C = CompTel, and E = EGRET.
The primary target's Right Ascension.
The primary target's Declination.
The primary target's Galactic longitude.
The primary target's Galactic latitude.
The designation of the primary target.
Estimated exposure of the target (in seconds). Off-axis targets
are weighted by the angular response function of EGRET and COMPTEL
The angle between target and z-axis of the spacecraft. This number
is important for EGRET and COMPTEL, which point in the z-axis direction.
Questions regarding the CGROTL database table can be addressed to the
HEASARC User Hotline.
If you have any problems, please consult the help
page or mail firstname.lastname@example.org