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This is the CGRO/BATSE Occultations database table. It contains entries for earth occultation data relating to several dozen pre-selected hard X-ray sources for each of which multiple X-ray lightcurves corresponding to different observing epochs have been constructed. Concatentation of all of the entries for a given source enables the user to construct an X-ray lightcurve for the duration of the CGRO mission that the public archive currently holds. Notice that it is possible in theory, using the original BATSE data, to construct similar lightcurves for any arbitrary point in the sky, but that the present database cannot be used in this way: those wishing to construct BATSE occultation lightcurves at positions not included here should contact the Marshall Space Flight Center BATSE group (


This database table was created by a cooperative effort of the HEASARC and the Compton Observatory Science Support Center (COSSC). It was last updated in November 2000.

Data Products

These are available only via the Browse Web interface. For each entry a `New History Light Curve' (nhis) FITS file and an `Occultation Lightcurve' GIF file are available. The nhis file contains data for one or more BATSE detectors for the available energy channels in the form of a source count rate (counts/sec) from which the background has been subtracted, and can be used to construct light curves. In addition, there is a FTOOLS program called bod2pha that can convert a BATSE nhis data file into a spectral (PHA) file. More information about bod2pha and other FTOOLS is available at:


The name of the hard X-ray source.

A unique observation ID that identifies each entry that is created from a concatenation of the string 'B.OCCULT_', the name of the target, the string '.', and the Truncated Julian Date (TJD) [which is equivalent to the Modified Julian Day Number - 40,000 days] corresponding to the start time of the observing segment. Thus, an observation of the source 4U1543-47 on 1997 December 18 (TJD=10800) has been given an obsid of 'B.OCCULT_4U1543-47.10800'. Notice that if the '+' character occurs in the name of the target, it is replaced by 'PLUS' in the obsid; therefore, the observation of GX1+4 that started on TJD 10800 has been given an obsid of 'B.OCCULT_GX1PLUS4.10800'.

The start time or date of the specified observing epoch.

The end time or date of the specified observing epoch.

The right ascension of the hard X-ray source.

The declination of the hard X-ray source.

The galactic longitude of the hard X-ray source.

The galactic latitude of the hard X-ray source.

Contact Person

Questions regarding the BATSEOCC database table can be addressed to the HEASARC User Hotline.
Page Author: Browse Software Development Team
Last Modified: Monday, 08-Nov-2004 11:23:45 EST