What kind of magnitude is listed in the Basic Data?
A.: These are usually optical magnitudes taken from the astronomical literature, and should be understood as being indicative only. We are adding letters after the magnitudes indicating the band pass to which the magnitude applies. For example, we use “U”, “B”, “V”, “R”, and “I” for the standard Johnson and/or Cousins magnitudes in the optical; “p” for photographic magnitudes from e.g. IIa-O or 103a-O plates, “g” for Gunn g-band magnitudes, “j” for magnitudes from III-aJ plates, “J” for 2MASS near-IR magnitudes, and so on. We will eventually have all of NED’s Basic Data magnitudes flagged with the band passes. In the meantime, the magnitude may have already been included in NED’s table of of referenced Photometric Data. • Q.: What are the sources for the photometric data in NED? A.: Most of NED’s detailed photometric data are taken from the larger catalogs, though we have also loaded many shorter lists from the journals as well. The Basic Data for each object, displayed on the Object S
