Sh2-273 (LBN 911, aka "Cone Nebula") Bright Nebula surrounds Dark Nebula in Monoceros

Located at: RA 06 hours 41 minutes 12 seconds; Dec +09 degrees 22 minutes 23 seconds

Size: ~ 6.0' x 2.6' Magnitude: -- Class: Emission (Sharpless) 3 2 3

North is up

West to the right

Telescope:

 14.5" f5 Newtonian reflector

Camera:

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

Image:

Lumicon Red filter, 680 minutes (68 x 10 minute subs), 03/7/8/9/2015; seeing 2.1-5.0 FWHM per CCDStack

Processing:

CCDStack 2.87.5531.19367, Photoshop CS5.1

Location:

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

Notes:

The 'Cone Nebula' is this little finger of dark nebulosity in a small southeastern part of the much larger object known as Sh2-273 (LBN 911). Sh2-273 is approximately 140' in size and irregularly shaped, and contains the open cluster NGC 2264, also known as the 'Christmas Tree' cluster. See the 8" version.

LDN 1613 seems to be the *closest* dark lane to the classic 'cone' shape of this nebula, but the CDS position of 06 40 42 +09 27 05 for LDN 1613 is too far west and north of my center of field (see above). However, by searching a 10 arc minute radius around the coordinates, the CDS turns up 854 objects (mostly stars). There are 5 dark nebulae listed, counting LDN 1613. The other four are DOBASHI 4753, 4754, 4755, and 4758. See explanation of DOBASHI.