Bow Tie Planetary Nebula (NGC 40)


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About this Image

This small planetary Nebula also named Caldwell 2 is showing a nice texture of red hydrogen, a round blueish core and two much fainter extensions opposite to each other.
The star has ejected its outer layer which has left behind a smaller, hot star with a temperature on the surface of about 50,000 degree C. Radiation from the star causes the shed outer layer to heat to about 10,000 degree C and is about one light-year across.

The nebula is located 3.700 light years away in the constellation of Cepheus.
North is up.

Find more information on this object here: 1.

Technical Details


16" cassegrain in corrected secondary focus at f/10

Mount ASA DDM-85XL
Camera SBIG STX16803 at -20C, STX filter wheel
Filters Baader 65x65mm LRGB
Date August 2012
Location Wildon/Austria
Sky Conditions mag 5.5 sky, raw FWHM 1.5-1.8", temperature 20 C
Exposure Ha:L:R:G:B = 60:480:60:60:75 minutes (30-minute sub-exposures for H-alpha, 15 min subs for LRGB)
Programs used Autoslew
Maxim DL 5
Photoshop CS5