8" f5 Newtonian reflector

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

Lumicon Deep Sky filter, 280 minutes (28 x 10 minute subs), 03/1/3/2008; seeing 2.1-3.5 FWHM per CCDStack

CCDStack 1.3.2, Photoshop 7.0

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

NGC 2261 is also known as "Hubble's Variable Nebula", and is located about 47 minutes SSW of the 'Cone Nebula' in Monoceros. Images taken over time show changes in the structure of this fan-shaped nebulosity. See the SEDS page for more details if this interesting object.

From the NGC / IC Project:

Contemporary Visual Observation(s) for NGC 2261

NGC 2261 = Hubble's Variable Nebula = LBN 920 = Ced 83 = R Mon = HH 39 = PP 64
06 39 10 +08 44.7
Size 2x1

13.1" (1/28/84): Hubble's Variable Nebula is bright, small, fan-shaped 2:1 N-S 
and widest at the north boundary.  The nebulosity tapers down towards 12th 
magnitude R Monocerotis at the south tip which appears to have a very small high 
surface brightness halo.  The western edge (oriented NW-SE) is slightly weaker 
and more curved than the eastern edge which is sharper and straighter N-S.  This 
is an impressive nebula with high surface brightness and interesting structure.

8": comet-like nebula extends from R Mon.

- by Steve Gottlieb

NGC 2261 is often called "Hubble's Variable Nebula" as its variability was 
indeed first noticed by Hubble during his years at Yerkes Observatory.  The 
nebula was discovered, though, by WH in 1783, and is the second of his new
class of "planetary" nebulae.  We know now that the nebulosity is actually
enveloping a very young double star system, R Monocerotis.  The star's 
variability was first noted by Schmidt (AN 55, 91, 1861).  The variability of 
the nebula is probably the result of circumstellar clouds close to the stars 
casting shadows on the surrounding nebulosity.  NGC 1554/5 (which see) around 
T Tauri is another example. - Dr. Harold G. Corwin, Jr.