B 68 (LDN 57) / B 69 (LDN 55) / B 70 (LDN 54) Dark Nebulae in Ophiuchus

Center of field at approximately: RA 17 hours 23 minutes 00 seconds, Dec -23 degrees 54 minutes 00 seconds

Size: 4.0' / 4.0' / 4.0' Magnitude: all three -- Class:  6 K G / 6 Ir / 4 C?

North is up

West to the right

Telescope:

 8" f5 Newtonian reflector

Camera:

 ST-8XME, self-guided, binned 1x1, temp -20c & -15C, camera control MaxIm DL 4.56

Image:

 Red (Hoya 25A) filter, 230 minutes (23 x 10 minute subs), 08/27/28/2006

Processing:

 CCDStack 1.1, Photoshop 7.0

Location:

  Rolling Roof Observatory, Thousand Oaks, CA 91360 (+34d 13m 29s -118h 52m 20s)

Notes: Another view of this amazing area of the southern Milky Way. This string of three (named) dark nebulae are just southwest of B 72, a portion of which can be seen at the upper left of this image. The bright star in both images is SAO 185357 at RA 17h 24m 04s,  Dec -23d 50m 39s. The largest, darkest spot is B 68, at upper right of center. Next, to the lower left of B 68, the two smaller spots are B 69. Skipping over the next little unnamed spot is B 70, the least impressive of the three.

These descriptions are from the on-line Edward Emerson Barnard "A Photographic Atlas of Selected Regions of The Milky Way":

68
α(2000)17h 22m 36s, δ(2000) -23 48
Galactic Coordinates 2,+7
 Small, irregular, sharply defined, diam. 4, about 20 SW of B 72
69
α(2000)17h 22m 56s, δ(2000) -23 56
Galactic Coordinates 2,+7
 Very small, irregular, sharply defined, extends N and S 4
70
α(2000)17h 23m 32s, δ(2000) -24 03
Galactic Coordinates 2,+7
 Diam. 4, sharply defined on W side