R.J. Mitchell discovered NGC 2847 one 15 Mar 1855 with LdR's 72", and noted a "F knot np [NGC 2848]". Harold Corwin identifies NGC 2847 as a star and HII region 0.6' NW of the nucleus of[NGC 2848. This is the most southerly deep sky object discovered at Birr Castle. Still, I found it very inconspicuous in the 48", so I have reservations of this identification.

900/1200mm - 48" (2/20/12): at 375x, a mag 16.5 star is superimposed on the northwest side (0.6' from center) of spiral NGC 2848 and attached to this star is an extremely faint HII knot. The faint star (possibly including the knot) was probably recorded by Lord Rosse's assistant R.J. Mitchell as a "faint knot north-preceding" and it received the designation NGC 2847. The RNGC misclassified the number as nonexistent.

Notes by Steve Gottlieb