Type | Unknown |
---|---|
Magnitude | Right Ascension | 17h 32' 42.7" (2000) |
Declination | 17° 31' 29" S |
Constellation | Ophiuchus |
Harold Corwin
IC 4657 and IC 4659 are presently lost. These are two of Barnard's unpublished nebulae that he sent directly to Dreyer; neither is at their IC positions. Nor are there stars nearby as Barnard claims -- "* 11 np 2 arcmin" IC 4657, and "* 8 f 21 seconds, 3 arcmin north" of IC 4659.
It's tempting to think that Barnard found these on the same night or on the same photographic plate; they are only about half a degree apart. Unfortunately, they are within a few degrees of the Galactic plane, so they might be two of the many asterisms in the area.
The neighboring stars and the relative positions are the only clues we have. Perhaps that will be enough, or perhaps we can dig into Barnard's observing logs again. Neither is seen in Plate 41 of Barnard's collection in Lick Publication, Volume 11, 1913, so I do not think that they were found photographically.
Cederblad included both objects in his catalogue of diffuse nebulae, probably because of the low Galactic latitudes. However, he admits in his notes that he has not been able to identify either one.
In addition to searching around the nominal positions, I also checked one and ten degrees north and south, and 1 minute of time east and west -- nothing. Perhaps one of the other obvious digit errors might yield the objects. Please look if you have the time and patience, and please let me know if you find them.― IC Notes by Harold Corwin
Barnard 276 | HD 159877 | IC 4659 |
PK5+6.1 | PK6+8.1 | PK7+6.1 |
PK7+6.2 | PK7+7.1 | |
TW Oph |
Drawings, descriptions, and CCD photos are copyright Andrew Cooper unless otherwise noted, no usage without permission.
A complete list of credits and sources can be found on the about page