Per Dreyer, NGC 6800 (= John Herschel's GC 4497, 1860 RA 19 21 23, NPD 65 08.4) is a "cluster, very large, pretty rich, very little compressed, stars from 10th magnitude". The cluster is a group of perhaps a hundred stars scattered across a region more than 20 arcmin in diameter, so the "center" is difficult to determine. The position listed above is more or less in the middle of the scattering of brighter stars, but different catalogs list positions differing from it (and each other) by several arcmins. Dreyer's position precesses to RA 19 27 11.9, Dec +25 08 25, which is southeast of some listed positions, but northwest of others; so the uncertainty in the modern positions is larger than the difference between any of them and Dreyer's position, and the identification must be considered certain, regardless of any supposed error in one position or another.

1.3 by 0.7 arcmin

Per Dreyer, NGC 6803 (= Pickering (HN 52), 1860 RA 19 24 39, NPD 80 13) is a "planetary nebula, stellar". The position precesses to RA 19 31 18.9, Dec +10 04 31, a little over an arcmin to the northeast of the nebula (roughly equidistant from NGC 6803 and the 11th-magnitude star just to its north), but there is nothing else which fits the description nearby, so the identification is certain. Stellar is indeed the appropriate description for NGC 6803, as it is only about 4 arcsec across, looks just like a star save at high magnification, and even then shows only the slightest hint of nebular structure. The main way in which amateurs can tell that such an object is a nebula is by using a filter (such as an OIII filter) which blocks most visible light, save for a narrow band centered on a wavelength at which interstellar gases emit their radiation. "Blinking" the field -- viewing it with, then without such a filter -- changes the brightness of normal stars far more than the brightness of nebulae, allowing the observer to pick out objects which don't change their brightness much. As it happens, that is not the way that Pickering discovered his planetaries. Instead, he placed an objective prism in the light-path of the telescope, which turned stellar images into short rainbows (or more accurately, since the eye cannot see color at low light levels, pale gray lines), but left nebulae as "stellar" objects, since they only emit light at a few wavelengths. The first pair of images below shows a normal closeup of NGC 6803 and a filtered view, in which the stars look much fainter. The following image shows a filtered closeup of the nebula superimposed on the "normal" image. The inset shows a 3 arcsec wide roughly circular core, surrounded by an almost as circular halo which extends another arcsec or so. Given estimates of the distance of the nebula (about 6 to 10 thousand light years from the Sun), the brighter core is a little over a tenth of a light year across, while the outer halo is a little less than twice that size.

Above and below, an example of how "blinking" a field -- observing it with and without nebular filters (such as an OIII filter) -- affects the appearance of stars and nebulae. Both images show a 50 arcsec wide image, and in each view NGC 6803 looks essentially stellar and relatively bright. But in the broad-spectrum visible light image above, the background of nearby stars is also bright, while in the filtered view below (Image Credits: Romano Corradi; used by permission) the stars are much fainter (in fact, I have enhanced the stellar images to make it easier to see that the two fields of view are the same).

NGC 6804 is four to six thousand light years from the Sun. Apparent size 1.1 arcmin, corresponding to perhaps 1.3 light years physical extent.

1.1 by 0.9 arcmin

1.2 by 0.8 arcmin

Per Dreyer, NGC 6807 (= Pickering (HN 51), 1860 RA 19 27 41, NPD 84 36) is a "planetary nebula, stellar". The position precesses to RA 19 34 34.5, Dec +05 42 07, about an arcmin north of the correct position, an error similar to that of NGC 6803, which shares a similar description and appearance. That object is about 5 arcsec across, and barely distinguishable from a star at high magnification; but NGC 6807 is only 2 arcsec across, and appears perfectly stellar regardless of the magnification used to view it. So even more so than in the case of NGC 6803, distinguishing the nebula from a star relies on using filters (such as an OIII filter) which block all light save the line emission radiated by interstellar clouds of gas (see NGC 6803 for a discussion of the technique involved). NGC 6807 is 15 to 20 thousand light years from the Sun. Given that, its apparent size corresponds to a diameter of a sixth of a light year.

Below, the non-stellar nature of NGC 6807 is revealed in a monochromatic (black and white) HST image (this is a "raw" image which has not had various kinds of errors, such as streaks caused by cosmic rays, removed). (Image Credits: ESA, NASA, Hubble Legacy Archive)

1.6 by 0.9 arcmin

(19 arcmin wide?)

The second IC adds "Not round, but considerably faint, small, considerably extended 170 degrees, stellar nucleus (DeLisle Stewart). h. called it once round, another time much extended". 1.2 by 0.9 arcmin

(15 arcmin wide?)

1.1 by 0.6 arcmin

3.0 by 3.0 arcmin

3.0 by 2.8 arcmin

The second IC says "Delete 'star to northwest' (not in Cape Obs.). There is a 14th magnitude star in position angle 20 degrees, distance 30 arcsec (per Howe)". 1.2 by 0.8 arcmin

0.7 by 0.6 arcmin. Listed in NED as NGC 6817 NED02.

0.2 by 0.2 arcmin

Between five and eight thousand light years away.

(5 arcmin wide?)

0.5 by 0.5 arcmin (a knot in Sharpless 2-86)

1.3 by 1.1 arcmin

The second IC says (per Howe) "Not large but very small". Dreyer and his successors made a number of mistakes in listing this galaxy and various parts of it which acquired NGC/IC listings of their own. A later iteration of this page will include a labeled version of the image below, to show which numbers correspond to which regions; but for now, refer to Steinicke's article for a discussion of the confusion involving the discovery (and mis-discovery) of this galaxy.
     The recessional velocity of NGC 6822 is -55 km/sec, meaning it is so close that its Hubble expansion velocity is less than its peculiar (non-Hubble expansion) velocity, and its distance cannot be determined from the velocity (although it can be inferred as being very close, intergalactically speaking). Redshift-independent distance estimates range from 1.4 to 2.3 million light years, with a "best" estimate of 1.65 milllion light years, making it one of the closest galaxies known, and a member of the Local Group of galaxies (which includes our Milky Way Galaxy and the Andromeda Galaxy). Because of its proximity NGC 6822 appears large (about 15.5 by 13.5 arcmin), but it is actually a dwarf galaxy, only about 8 thousand light years across.

(7 arcmin wide?)

1.9 by 1.4 arcmin

0.5 by 0.3 arcmin

NGC 6826 is three to five thousand light years from the Sun.

Below, a HST image of the central portion of the nebula (Image Credits: Bruce Balick (University of Washington), Jason Alexander (University of Washington), Arsen Hajian (U.S. Naval Observatory), Yervant Terzian (Cornell University), Mario Perinotto (University of Florence, Italy), Patrizio Patriarchi (Arcetri Observatory, Italy) and NASA)

(2 arcmin wide?)

1.6 by 0.4 arcmin

(6 arcmin wide?)

1.4 by 1.4 arcmin

(12 arcmin wide?)

Per Dreyer, NGC 6833 (= Pickering (HN 54), 1860 RA 19 45 47, NPD 41 23.5) is a "planetary nebula, stellar". As for NGC 6803 and 6807, which share the same discoverer and description, the 5 arcsec disc of NGC 6833 is indistinguishable from a star in visual or broad-spectrum photographic surveys. Only the use of filters (such as an OIII filter) which block most wavelengths but pass the radiation emitted by interstellar gases allows an observer to tell the difference between ordinary stars, which look fainter when viewed through such filters, and planetary nebulae, which remain about the same brightness. NGC 6833 probably lies in the next spiral arm out from the center of our galaxy, or even in the inner halo beyond that arm, which would put it at least seven thousand light years from the Sun, and most likely considerably further.

Below left, a HST closeup of the star shows a faint outer disk about 5 arcsec in width (Image Credits: Hubble Legacy Archive). Below right, a composite HST image shows a low-ionization region about one arcsec in size, centered on the star (Image Credits: WFPC2/PC Casertano GO6943, NASA/ESA/STScI, Hubble Archives)

(6 arcmin wide?)

2.4 by 0.7 arcmin

The second IC says (per Howe) "13.5 magnitude star attending to east". 1.7 by 1.5 arcmin

(3 arcmin wide?)

(4 arcmin wide?)

(4 arcmin wide?)

1.5 by 1.4 arcmin

(4 arcmin wide?)

1.4 by 1.1 arcmin

2.3 by 1.0 arcmin

1.1 by 0.6 arcmin

0.6 by 0.2 arcmin

0.7 by 0.2 arcmin

(0.8 arcmin wide?)

2.4 by 1.0 arcmin

1.9 by 1.1 arcmin