NGC/IC Project Restoration Effort

===== NGC 7000, the North America Nebula. WH saw only a small part of the brightest, southern-most portion of this huge emission region, "Central America." His published description reads "vL diffused nebulosity, bM. 7 or 8' l[ong], 6' b[road], and loosing itself vg and imperceptibly." In the sweep from 24 October 1786, we see "vL diffused nebulosity plainly visible, bM; 7 or 8' l, 6' b, and loosing itself gradually." The offsets are those published, and CH's reduced position has no errors. Interestingly, WH goes on just a minute later in the sweep to write, "All this time suspected diffused nebulosity throughout the whole breadth of the sweep. RA from 20 52 09 to 20 55 46, PD from 45 35 to 48 38." This corresponds to approximate limits of 20 59 22 to 21 03 02 and +42 09 to +45 12 for J2000 which covers the eastern half of the North America Nebula and some considerably fainter nebulosity extending on south. This is part of the 44th entry in WH's list of "extensive, diffused nebulosity" which he published in 1811 (See Phil. Trans. 101, 269). While many of these areas have been shown as illusory (see e.g. A. Latusseck, JAHH 11, 235, 2008 and JAD 14, No. 4, 2008), some -- including this one -- are not. JH was uncertain if his father had in fact seen the same nebulosity as he did, as WH's position is nearly a degree south of his own (I put the approximate center even further north than JH did). JH's description makes it clear why he put a question mark on his father's number in his 1833 list (the query persists through the GC to the NGC itself): "An immense nebulosity all around this place, but too ill defined to fix the limits. RA that of V 37, from working list, not being settled by the obs." This raises a couple of minor mysteries about this nebula. WH claims only one observation of it in his published catalogue, as does JH in his. Yet, in GC, JH has the total number of observations by himself and his father as "3." Even though JH claims that his RA is from the working list (i.e. his father's observation), the RA he quotes is nearly a minute of time larger than WH's published RA. The RA that JH adopts for GC is not quite a mean of the two values, but is closer to WH's original. I wonder if WH had another observation that he somehow overlooked when it came time for publication. Wherever JH got his position, it is more or less appropriate for the entire nebula that we now call the North America Nebula, so I've adopted a position pretty close to it for NGC 7000. I have, however, given a separate position for the bright section of it that WH saw.

===== NGC 7000 18" (7/16/07): superb view of the entire North American nebula in the 80mm finder at 12.5x and at 73x in the 18-inch with UHC filters in both. The entire outline of the U.S., Mexico and Central America was well-defined and very high contrast with the surrounding dark fields particularly around the Gulf of Mexico region (LDN 935) and the West Coast. A 7th magnitude star is at the edge of the center of the gulf (Texas area) and another 7th magnitude star is at the south tip of Florida. The "Baja peninsula" and Central American extension jut out very prominently from the gulf region. The edge of the northern Canadian region is less well defined. Open cluster NGC 6997 was very prominent on the East Coast (west side of the nebula). It was breathtaking to scan around the entire outline, though it overfilled the 67' field. 17.5" (7/17/93): at 100x and OIII filter appears very bright, extremely large (fills several fields), amazingly high contrast around the "Gulf" of Mexico and "Baja" region (LDN 935) and to a lesser extent along the west and east coasts. I traced around the entire border except for the "Canada" region, which consists mostly of scattered star fields with weak nebulosity. The open cluster NGC 6997 is easily picked out in the NE section. 8": bright, very large, sharp border and details around the "Gulf" section, "Southwest border" and "Baja region". Rich with faint stars. Viewed with a Rich Field adapter at 33x-50x. 80mm (8/23/84): striking contrast at 16x using a filter at Mt. Rose. 80mm (5/26/84): bright with a well-defined "Gulf" region at 13x using a narrowband filter. Naked-eye: Easy naked-eye glow in a dark sky, though this is mostly from the rich Milky Way star cloud and not the involved nebulosity. The contrast is highest on the southwest side where the star cloud and nebulosity is adjacent to the dark "Gulf of Mexico" region.