Thors Helmet NGC 2359 as seen in the backyard from January 18 to 20, 2013.

This nebula is the result of the energetic eruption of gas from a large star known as a Wolf-Rayet type. These are short-lived, massive stars that burn brightly and shed a large amount of their atmosphere in a growing envelope of glowing nebulosity.

This example is particularly interesting because of the appearance like a winged helmet.

This is a stack of 83 frames of 600 seconds at 400 ISO for an integration time of nearly 14 hours. There were some significant framing errors and so I had to crop much of the edge of the field. Also, weather did not agree and many of the subs were taken through a high haze.

Even so, this has turned out well and shows nicely. If I got out of town and up to a darker site it would have looked better also because of the position in the sky. There was a small window of decent sky between trees and a streetlight thus the challenges of getting good exposures.

As usual, this is with the Stellarvue SV4 and the Pentax K10D camera.

Guided and Calibrated using Maxim

Registered, Stacked, and Debayered with DSS

Processed with PixInsight

Here's the Platesolve (valid only for the full field of view and not the cropped version):

Referentiation Matrix (Gnomonic projection = Matrix * Coords[x,y]):

+0.000017553998 -0.000530443533 +0.573450106035

+0.000530602574 +0.000017061182 -1.037259991147

+0.000000000000 +0.000000000000 +1.000000000000

Resolution ........ 1.911 arcsec/pix

Rotation .......... 91.878 deg

Focal ............. 655.20 mm

Pixel size ........ 6.07 um

Field of view ..... 2d 2' 10.2" x 1d 12' 54.0"

Image center ...... RA: 07 18 45.558 Dec: -13 13 13.03

Image bounds:

top-left ....... RA: 07 21 07.525 Dec: -14 15 24.00

top-right ...... RA: 07 21 22.876 Dec: -12 13 17.19

bottom-left .... RA: 07 16 06.946 Dec: -14 13 02.81

bottom-right ... RA: 07 16 24.793 Dec: -12 10 57.21