Other photometric observations (detections)

Due to overlaps in imaging stripes, the SDSS sometimes observes the same object more than once. In such cases, we select one observation as PRIMARY (mode=1). Each astronomical object is assigned a thingID, and each time that "thing" is observed (detected in SDSS imaging), it assigned a separate objID.

Information about each astronomical "thing" is stored in the thingIndex table; thingIndex is a thin coupling table designed only to connect repeat observations. Information about each individual observation (detection) is in the photoObjAll table. (Note that photoObj contains only the primary [mode=1] and secondary [mode=2] observations of each "thing.") The detectionIndex table connects each objID to the thingID it corresponds with.

This detected object and its associated "Thing" (Primary observation)

IAU name	objid	thingid	mode description
SDSS J151806.13+424445.0	1237662301903192106	449814716	PRIMARY

Other Observations of this "Thing"

objid	thingid	mode	mode description
1237662301903192106	449814716	1	PRIMARY