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Tuesday, January 8, 2013

An emission nebula NGC 1491

A start of the new imaging project.
I'll shoot other two emission channels, needed for a color image, as soon as the weather allows.

NGC 1491
in constellation Perseus

NGC 1491 in H-alpha emission light


NGC 1491 is an emission nebula found in the constellation of Perseus at the distance of about 10700 light years. The ultraviolet light from the newly born stars makes elements in the nebula glow. There is an an 11th magnitude star in its center.  The solar wind, a radiation pressure, from the central star is blowing a bubble in the gas surrounding it. This is a dim one, seven hours of exposures was barely enough to reveal it.

A closeup

A detail from the center of the image above

A popular shape in our local universe

While processing the image, I noticed a familiar shape in the center portion of the image.
It seems to repeat itself in various targets. My guess is, that it's coursed by the solar wind from the open cluster usually locates in center of the emission nebula of this type.   

A collection of targets with same type of shapes as can be seen in center of the this new image.
The top most two images are from NGC 1491.

Technical details:

Processing work flow:
Image acquisition, MaxiDL v5.07.
Stacked and calibrated in CCDStack2.
Levels, curves and color combine in PS CS3.

Optics, Meade LX200 GPS 12" @ f5
Camera, QHY9
Guiding, SXV-AO, an active optics unit, and Lodestar guide camera 5Hz
Image Scale, ~0,8 arc-seconds/pixel
21 x 1200s exposures for the H-alpha, emission of ionized Hydrogen = 7h

An experimental starless image

A starless image to show only the actual nebula

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