Skies By Africa

Images of the Heavens By Eric Africa

M97, the Owl Nebula

M97 is a nice example of a planetary nebula. It is well-sized, though smaller (about half the size) of the Dumbbell Nebula (M27). Specifically, according to the Seds Messier database (, the dimensions of M27 are 8.0 x 5.7 arc-minutes, while M97 is 3.4 x 3.3 arc-minutes in size.

M97 is well-placed in the northern sky, sitting "under" the bowl of the Big Dipper. As described in the Nebula home page of this website, this object is the gaseous outer envelopes of a star similar in mass to our Sun that has completed its red-giant phase. Undergoing a process that is still not well-understood, the outer layers of the red giant are being ejected by the object's central star. Ultraviolet and other radiation from the central star excite the atoms of the gas being ejected, causing it to glow and revealing the object to us.

Planetary nebulae don't glow for very long by cosmic standards. Estimates are that they glow for a few tens of thousands of years, which is a blink of an eye given a star's typical lifetime of a few billion years. The reason for the relatively short lifetime of planetary nebulae is that as the central star settles down to its white dwarf phase, the radiation that causes planetary nebulae to glow also fades and the gases stop glowing. Given M97's estimated age of 8,000 years, we better enjoy this object while it lasts!

M97 is nicknamed the Owl Nebula thanks to an illustration by William Parsons, the 3rd Earl of Rosse. His observation and hand-drawn illustration resembled an owl's head, most likely from the two dark lobes visible even in my image.

Source: Wikipedia, Seds database
Constellation: Ursa Major
When Visible: January - July
Distance: 2,000 Light-years
Date: March 2014
Location: Rancho Hidalgo, New Mexico
Exposure Details:
Luminance: 17 x 10 Minutes Binned 1x1
H-Alpha: 22 x 30 Minutes Binned 1x1
R: 13 x 10 Minutes binned 1x1
G: 13 x 10 Minutes binned 1x1
B: 13 x 10 Minutes binned 1x1
Equipment used: 12.5" PlaneWave CDK on a Software Bisque Paramount ME mount. SBIG STL-6303 camera with 5-position filter wheel and Astrodon LRGB filters.
Acquisition Software : MaximDL, CCDAutopilot 5, TheSky6, FocusMax
Processing Software: Software: MaximDL, Adobe Photoshop CS5 Gradient Xterminator, Carboni Tools, IrFanView