NGC/IC Project Restoration Effort

===== NGC 6822 = IC 4895, which also see. The IC number is easily explained, but I am a bit puzzled at the record concerning NGC 6822 itself. William Sheehan, in his biography of Barnard "The Immortal Fire Within" has the galaxy being "swept up with the 5-inch Byrne refractor in 1884". However, in his short note on its discovery in Sidereal Messenger, Barnard says that he used the 6-inch refractor to determine its position, and that it is in the same low- power field (in the 6-inch) as the well-known planetary nebula, NGC 6818. Barnard is also a bit parsimonious with his description of the galaxy, calling it only "exceedingly faint". There is nothing about its size or shape, so the NGC description "vF, L, E, dif" probably reached Dreyer in a letter. This galaxy is important historically as it is the subject of Edwin Hubble's first published paper on Cepheids in external galaxies. Though he announced the discovery of extragalactic Cepheids in M 31 in 1924, he chose NGC 6822, "a remote stellar system", as the first to have his systematic studies reported in the Astrophysical Journal (Volume 62, page 409, 1925). M 33 and M 31 followed in 1926 and 1929, respectively. So, extragalactic astronomy begins here, too.

===== NGC 6822 48" (5/16/12): the four HII regions on the north side of the galaxy were carefully observed. IC 1308 = Hubble X appeared bright, fairly small, irregularly round. At ~30" diameter this HII knot is slightly larger than Hubble V and more uniform in surface brightness. Hubble V is bright, fairly small, irregularly round. This irregular HII region spans 20"-25" and has a higher surface brightness than IC 1308 3' E. A bright knot is on the SE end. Hubble III was immediately visible as a faint to fairly faint glow, fairly large (largest of the four regions), round, ~0.9' diameter. Occasionally, when the seeing steadied the ring structure popped and a brighter rim and darker center was visible. Smaller and slightly fainter Hubble I is virtually in contact at the NW edge and sometimes the two glows merged into a single large, irregular glow. Hubble I is the faintest and westernmost of the main HII regions and appeared as a faint, moderately large, round glow of ~36" diameter, barely off the NW side of larger Hubble III. 18" (8/12/10): under superb conditions at Lassen (8200'), I tracked down Hubble VII, the brightest and oldest globular cluster in Barnard's galaxy, situated near the center of the galaxy. At 285x, the globular was visible ~50% of the time as an extremely faint (~16th magnitude) and small glow, ~10" diameter. I couldn't resolve an extremely faint star attached on the SSE edge, but the glow was definitely non-stellar. I also viewed this challenging object at 393x and it appeared roughly similar in terms of visibility. 18" (7/16/07): very easily picked up at 73x as a very large, low surface brightness glow with no central concentration and extending ~5:2 N-S, ~11x4.5'. The two HII knots at the north end (IC 1308 and Hubble V) were blinked with an OIII or UHC filter and showed a good response. Surprisingly the galaxy was quite evident in my 80mm finder at 25x as a faint, elongated glow and it was just at the edge of visibility in my 15x50 IS binoculars. 17.5" (7/14/99): the exact position of the HII ring Hubble III on the NW side of the galaxy was examined carefully at 280x without a filter and on several occasions an extremely faint, round, 15" glow popped into view with averted vision ~1.5' W of a mag 13.5-14 star. A mag 15.5 star is visible a similar distance SSE of the reference star. This HII knot was clearly nonstellar, although it didn't have the annular ring appearance seen on images. Viewed on an evening of exceptional transparency at the Sierra Buttes. 17.5" (5/10/91): at 82x, this Local Group Member appeared fairly faint, very large, low but uneven surface brightness, elongated 5:2 N-S, 14'x6'. Diffuse appearance and the boundary is difficult to define, requires low power. Several faint stars are superimposed with a couple of brighter stars on the north side. Using an OIII filter two small, faint HII knots (Hubble X = IC 1308 and Hubble V) stand out well on the north and NW edges. Both of these knots are 2' NW of mag 12 stars. Planetary nebula NGC 6818 lies 40' NNW. 17.5" (7/16/88): easily visible as a large, elongated, low surface brightness glow. 8" (8/28/81): very faint, elongated N-S, similar to a faint Milky Way patch.