NGC 7822 - Ced 215
FCL-90 II (ag, ST-4)
ST-10XME, LRGB, 5 minute subs
A faint emission/SNR type nebula in Cephus is located approximately 1.5 degrees North of Ced 214.
Note - the two bright stars at top center are HD 224825 and HD 225123 (left to right). Image orientation is CCW from the top NESW
NGC 7822 is one of many entries in the NGC catalog in question.
John Herschel discovered and cataloged NGC 7822 in 1829. The discrepancy occurred when J. Draper (date unknown) could not detect nebulosity at what he believed to be the correct location but cautioned his pointing might be in error. Draper tried on two separate occasions but may have been using the same coordinates as in his initial attempt.
There are no other historical reports or discussion that I could find on NGC 7822. The discussion started after John Roberts 90 minute photographic plates (1901-1902) showed nebulosity near the area of J. Drapers observation.
Cederblad cataloged the area of nebulosity in 1945. "The Catalog of bright diffuse Galactic nebulae was compiled in the frame of a thesis investigating the spatial distribution and the geometrical properties of bright diffuse Galactic nebulae, together with some inquiries into the interstellar absorption problem. It is a mostly complete compilation of the knowledge about bright galactic nebulae around 1945." (http://adsabs.harvard.edu/abs/2001yCat.7231....0C). The Catalog entery for Ced 2114 and Ced 215 (NGC 7822) follow.
Ced Cederblad Catalog of bright diffuse
Galactic nebulae (Cederblad, 1946) (330 nebulae)
(Lund Medd. Astron. Obs. Ser. II, 119, 1 (1946))
GlLon GlLat Star
pmag vmag SpType logal SpNeb Class Dim1 Dim2
plx Method Dist x
AMin AMin ASec pc pc pc pc
214 a +66
1676 23 57.3 + 66 36 86.7
+5.2 +66 1676 8.4:
7.8 G O 0.686
c B2 16
214b +66 1679 23 59.2 +66 36 86.0 +4.9 +66 1679 6.84: 5.84 KO 0.878 c B2 25 20 0.009 ach 110 +8 +109 +9
215 NGC 7822 23 59.6 + 68 0 86.3 +6.4 Cl 6.0 : A0, ? 1.215 C A1 60. 30. 0.0012 acn 800 +51 +794 +90
The notes from the catalog are as follows
214 The nebula surrounding the two stars +66 1676 = HD 224992, and 214 +66 1679 = HD 225216 = Boss 39. R. Erroneously identified as NGC 7822 214 by Roberts in (624). (630 Pl 20). 215 NGC 7822 = GC 5051 = h 2302. R. The coordinates and the description given 215 by John Herschel must refer to the nebulous cluster containing the HD 215 stars: +68 1423 = HD 225123, and +67 1588 = HD 224825. 215 Compare (630) Pl 20. (114, 304, 631).
Note the dimensions of Ced 214a and 214b compared with the NGC 7822 (Ced 215)dimensions.
The original Hershel dimensions for NGC 7822 was 20x3 but he did discuss a possible larger area 60" observed when sweeping the area on an "exquisite night", the area was so faint that he was unsure of his observation.
The NGC/IC Project (Project) revised the NGC 7822 coordinates because of conflicting records by J. Draper and J. Herschel, this in addition to Roberts mis-identification of Ced 214 (from note in Cederblad catalog) as NGC 7822 caused the Project to assign NGC 7822 to a spot on the outer edge of Ced214.
15'x15' image is from the DSS for the coordinates of NGC 7822 as modified by the
The Project did keep the original size (20' x 4') which more fits the Herschel's object but seems hard to reconcile to the above object. Note - the two bright stars are (top) HD 224992 and (bottom) HD 225216), image orientation is CCW from left NESW.
Of real interest is the fact the visual observing report used by the Project reported visual identifying faint nebula at the original NGC 7822 location but was unable to identify nebulosity in either Ced 214 or the project location for NGC 7822 without the use of filters. I've only had one visual observer that reported visually observing Ced 214 without the use of filters.
Herschel saw nebulosity at his reported location, Draper didn't but cautioned his pointing might not have been accurate and Roberts used 90 minutes photo plates to detect Ced 214 and didn't even address the nebula at the Herschel location (Cederblad did use the Robert plates).
Go to the following and click on NGC 7822 for
the Project's discussion on changing the location of NGC 7822.
Note the Project indicated the new location was also cataloged as Ced 215 generating another catalog discrepancy for some future project to correct.