An unexpected clear night, so I left the camera taking pictures till 7 am, well into the morning light. The image is based on:
Gain : 139; offset 50
Exposure length 114s
Luminance x 112
Red x 42
Blue x 44
Green x 15 (lost a few because of dawn)
I used darks, flats and dark flats for the L channel and flats for the RGB channels.
M97 is a planetary nebula, the remnants of a star that has grown to a red giant then 'blows' off its atmosphere and shrinks to a white dwarf. In this image there are a couple of distant galaxies visible too.
Messier 97 (M97), also known as the Owl Nebula, is a famous planetary nebula located in Ursa Major constellation.
The nebula lies at a distance of 2,030 light years from Earth and has an apparent magnitude of 9.9. It has the designation NGC 3587 in the New General Catalogue.
Messier 97 occupies an area 3.4 by 3.3 arc minutes in apparent size, which corresponds to a spatial diameter of 1.82 light years. It was named the Owl Nebula because of its appearance in larger telescopes, which reveal two dark patches that look like the eyes of an owl. These were first sketched by William Parsons, 3rd Earl of Rosse in 1848.
Like most planetary nebulae, M97 appears brighter visually than photographically because it emits most of its light in one green spectral line. Its outer halo was not detected until 1991 (I havent picked this up in my images, I need a lot more subs ). The nebula formed when a dying Sun-like star ran out of hydrogen fuel, collapsed from a red giant to a white dwarf, and ejected its outer envelope. The expelled material is now heated by the radiation of the central white dwarf, producing the nebula’s glow. The nebula has been gradually expanding and will completely disperse into space over the next several thousand years, while the white dwarf will cool and fade away over the next several billion years.
The estimated age of the Owl Nebula is about 8,000 years. The nebula is expanding at a velocity in the range from 27 to 39 km/s. It contains about 0.13 solar masses of material, including the elements hydrogen, helium, nitrogen, oxygen and sulphur. The matter within the nebula has a density of less than 100 particles per cubic centimetre.
Gain : 139; offset 50
Exposure length 114s
Luminance x 112
Red x 42
Blue x 44
Green x 15 (lost a few because of dawn)
I used darks, flats and dark flats for the L channel and flats for the RGB channels.
M97 is a planetary nebula, the remnants of a star that has grown to a red giant then 'blows' off its atmosphere and shrinks to a white dwarf. In this image there are a couple of distant galaxies visible too.
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| The Owl Nebula, Messier 97 |
Messier 97 (M97), also known as the Owl Nebula, is a famous planetary nebula located in Ursa Major constellation.
The nebula lies at a distance of 2,030 light years from Earth and has an apparent magnitude of 9.9. It has the designation NGC 3587 in the New General Catalogue.
Messier 97 occupies an area 3.4 by 3.3 arc minutes in apparent size, which corresponds to a spatial diameter of 1.82 light years. It was named the Owl Nebula because of its appearance in larger telescopes, which reveal two dark patches that look like the eyes of an owl. These were first sketched by William Parsons, 3rd Earl of Rosse in 1848.
Like most planetary nebulae, M97 appears brighter visually than photographically because it emits most of its light in one green spectral line. Its outer halo was not detected until 1991 (I havent picked this up in my images, I need a lot more subs ). The nebula formed when a dying Sun-like star ran out of hydrogen fuel, collapsed from a red giant to a white dwarf, and ejected its outer envelope. The expelled material is now heated by the radiation of the central white dwarf, producing the nebula’s glow. The nebula has been gradually expanding and will completely disperse into space over the next several thousand years, while the white dwarf will cool and fade away over the next several billion years.
The estimated age of the Owl Nebula is about 8,000 years. The nebula is expanding at a velocity in the range from 27 to 39 km/s. It contains about 0.13 solar masses of material, including the elements hydrogen, helium, nitrogen, oxygen and sulphur. The matter within the nebula has a density of less than 100 particles per cubic centimetre.
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