E.E. Barnard visually discovered IC 4587 on 27 Apr 1903 while observing the variable star (recurrent nova) T Corona Borealis, normally around 10th magnitude (currently mag ~9.2) but blazed to second magnitude in 1866 and third magnitude in 1946. From 1903 to 1907, he periodically looked for evidence of a change in color or indication of a non-stellar appearance using the Yerkes 40-inch refractor. In a report published in ApJ, 25, 279 (1907), he reported, "While examining the star, I found a faint nebula in the field with it, following. The nebula is of the 14th or 15th magnitude, and is from 5" to 10" in diameter, without any nucleus." This object is apparently Barnard's last visual discovery.

600/800mm - 24" (7/28/19): at 322x; faint, small, round, 18", very small brighter nucleus, small halo with averted. Located 5' ENE of recurrent nova T Corona Borealis, nicknamed the "Blaze Star". Normally about 10th magnitude, it increased to mag 2 and 3 in 1866 and 1946, respectively.

Notes by Steve Gottlieb