To search an area on the sky, provide the center location and search radius:
The coordinates or object name entered will be resolved by NED or SIMBAD. By default, NED is contacted first; if no matching location is found, SIMBAD will be searched. For stellar objects, SIMBAD locations may be more accurate. To instruct the search program to attempt to resolve the location using SIMBAD, check the radio button labeled "SIMBAD first."
Please note that observations taken of a specific object (i.e., M51) may not be returned when you perform a spatial search for that object, if the RA and DEC values of the observation are too far away from the NED or SIMBAD location of the object. If you don't see the results you expect when doing a spatial search by object name, try increasing the "Radius" value to increase the search area, or switching to "Search by TARGNAME keyword" (below).