Astro Images

 Designations: M76, NGC 650 and NGC 651, Little Dumbbell Nebula
Object Type: Planetary Nebula
Constellation: Perseus
RA: 1h 42.4min
Dec: +51deg 34 min

Visual Magnitude: 10.1
Size: 67"
Distance: 3,900 light years
Discoverer: Pierre Mechain, 1780

Visual Description: "Smaller, fainter and less popular than its cousin the Dumbbell Nebula (M27) in Vulpecula, the Little Dumbbell in Perseus is nonetheless a very dramatic planetary.  Sometimes, unfortunately, the popularity of an M object seems to be based more on how bright or large it appears in the night sky than on how much detail it reveals through the telescope.  But in the case of M76, its beauty lies not in its visual punch, but its wealth of subtle detail, which lures small-telescope users into a web of visual suggestions.  I'd place it amongst the most surprising and mysterious objects in the Messier catalogue for viewing with backyard telescopes.  Certainly astronomers at the turn of the century must have been awed by its image in long-exposure photographs.  Instead of a ghostly ring or disk of light encircling a central star - as is characteristic of planetaries - here was a 16th-magnitude central star in a rectangular bar of light made up of two prominent nebulous patches ( thus the double NGC entry ) flanked by an irregular array of luminous knots and nebulous arcs.  In 1891 Isaac Roberts suggested that M76's unusual character is due to our seeing its broad ring of material edgewise.  But the object's compex appearance might derive more from the way gases of varying densities near the central star illuminate and obscure the star's light."[1]

M76 is about five times more distant than M27, but they are about the same actual size, so M76 only appears smaller.  Some catalogues severely underestimate the brightness of the Little Dumbbell, listing it as 12th Magnitude, which is much too faint.  Indeed, as proof, M76 is at the limit of detectability in 7X35 binoculars, which is about 10th magnitude.  

Seeing Conditions: Above average (Indianapolis clear sky clock seeing 5/6, transparancy 5/6, clouds 6/6 ) 

Telescope: 10" LX200 OTA
Focal Length: 2500 mm (F10)
Mount: Takahashi NJP 160
Camera: Starlight XPress MX916
Exposure: Multiple 10 minute exposures
Other: SBIG STV guider

Image Processing:

Astro Images

doug@dougsastro.net

Copyright(c) 2007 Doug Sanqunetti. All rights reserved