M97 - Owl Nebula

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Designations: M97, NGC 3587
Object Type: Planetary Nebula
Constellation: Ursa Major
RA: 11h 14.8m
Dec: +55 deg 1m

Visual Magnitude: 9.9
Size: 2.8 min
Distance: 1630 light years
Discoverer: Pierre Mechain, 1781

Visual Description: This distinctive planetary nebula, so strongly reminiscent of the face of an owl (at least in photographs), is a real challenge for small telescopes because its faint light is spread over an are roughly five times the size of Jupiter's appaent disk. Thus, to see the Owl Nebula well, one needs to be under a dark sky. The glow will probably elude anyone using a telescope with an aperture smaller than 6 inches and one needs at least a 12-inch instrument to see the "eyes" of the Owl. M97 earned the "Owl" moniker from a sketch made by Rosse in 1848, who through his 72-inch telescope spied the two dark holes that look like eyes peering spookily from a round face. The Owl is certainly challenging, especially from a city.

M97 is one of the more complex planetary nebulae. Its appearance has been interpreted as that of a cylindrical torus shell (or globe without poles), viewed oblique, so that the projected matter-poor ends of the cylinder correspond to the owl's eyes. This shell is enveloped by a fainter nebula of lower ionization. The mass of the nebula has been estimated to amount 0.15 solar masses, while the 16 mag central star is believed to be of about 0.7 solar masses. Its dynamical age is about 6,000 years. (from Stephen J. Hynes, Planetary Nebulae).

Seeing Conditions: Not Recorded

Telescope: TMB 152mm APO refractor
Focal Length: 1200 mm
Mount: Takahashi NJP
Camera: SBIG ST10XME
Exposure: 12 7-minute exposures (84 minutes total)
Other: SBIG AO-7 adaptive optics

Image Processing: CCDStack and Photoshop CS2

The Visual description of the M97 was written by Steven James O'Meara in the book "The Messier Objects" by Stephen James O'Meara. Page. 257. ISBN number 0-521-55332-6.

Astro Images

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