Browse
this table...

CGROTL - CGRO Timeline

HEASARC
Archive

Overview

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.


References

The Compton Observator Science Support Center observation timelines are available at http://cossc.gsfc.nasa.gov/docs/cgro/timeline/.

Provenance

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.

Parameters

Cycle
The proposal phase/cycle number.

View_Period
The viewing period of the observation.

Start_Date
The start date of the viewing period.

End_Date
The end date of the viewing period.

Prnb
The unique proposal number from which the observation was derived.

PI_LName
The last name of the Principal Investigator of the observation or the instrument team.

Instrument
The instrument(s) used for the observation, where O = OSSE, C = CompTel, and E = EGRET.

RA
The primary target's Right Ascension.

Dec
The primary target's Declination.

LII
The primary target's Galactic longitude.

BII
The primary target's Galactic latitude.

Name
The designation of the primary target.

Exposure
Estimated exposure of the target (in seconds). Off-axis targets are weighted by the angular response function of EGRET and COMPTEL respectively.

Z_Angle
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.


Contact Person

Questions regarding the CGROTL database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: 23-Aug-2005