M 27 - The Dumbbell Nebula

General Observations

Messier discovered M 27 in 1764. Some twenty years later, William Herschel recognised its peculiar shape. His son, John, called it the Dumbell and the moniker stuck. In the 19th century, Huggins observed that it wasn't composed of unresolved stars as was originally believed, but through the new science of spectroscopy, realised M 27 was in fact a gigantic cloud composed of luminous gas.

Along with M 57, the Ring Nebula, M 27 is one of the most observed deep space objects (DSOs) in ameteur astronomy and there is an obvious reason for this: it is a giant of a planetary nebula with a high degree of surface brightness which takes high magnification remarkably well.

What you are seeing is essentially the remains of a dying supergiant star whose decomposition is creating boundaries of chaos where hot, ionized gas is pushing out onto older, cooler gaseous clumps. M 27's inner section is made up of huge structures of gas and dust somewhere between 20 to 60 million kilometers in size containing the matter of about 3 or 4 times the mass of Earth. These superstructures - for want of a better word - have sufficient density to cast opaque shadows onto the lighter, cooler outer regions giving the nebula that peculiar 'dumbbell' shape.

The total diameter of M 27 is estimated to be about 6 light years across whose boundary is said to be expanding about 2 to 3 inches every century, whilst its inner region at about 6 to 8 inches. M 27 is between 1,150 to 1,350 light years away with an age of around 9,000 to 10,000 years, making it a relatively young nebula. M 57, for example, is about twice as old.

City Observations

The first time I stumbled upon M 27 I had to double check the late night sky to make sure I hadn't found a solitary, wandering cloud; after observing smaller, fainter, nebula structures, I wasn't prepared for the sheer size of the thing. At low magnification it appears as a large, fuzzy cloud-like patch of an indeterminate nature, a blob, so to say, but with the aid of the UHC-S Nebula Filter (Baader), its famous two lobe structure is brought out.

I have included sketches both without the filter (on the right) and with the filter (on the left) which will hopefully give some idea of what is being viewed. I thought it was also a good idea to include these two sketches for it may help future astronomers decide if the filter is worth its price or not. Note how the nebula is brought-out with the filter, how it takes on a more defined structure but with a notable reduction in star content. It follows that the UHC-S will be pretty redundent when hunting down nebulae.

The sketches were made using white and grey chalk and brush for the nebula itself, whilst a finely sharpened, white charcoal pencil was used for plotting the stars on the black paper.