Focal Pointe Observatory
Astrophotography by Bob Franke

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M1 - The Crab Nebula

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Click the image for a wider ~ 75% size view. (2400 x 1600 - 1.18 MB)

"Mouse Over" view is LRGB only

Instrument

12.5" RCOS @ ~ f/9 (2880 mm fl) at 0.64 arcsec/pixel. Shown at 0.5 and 0.83 arcsec/pixel.

Mount

Paramount ME

Camera

SBIG STL-11000 w/ FW8 filter wheel, AstroDon Gen-2 LRGB &  a 6nm Ha filter.

Acquisition Data

11/20/2015 to 2/2/2016 Chino Valley, AZ.  with CCD Commander & CCDSoft.  AOL guided

Exposure

Lum

495 min (33 x 15 min) Bin 1x1 (best of 53)

RGB

540 min (12 x 15 min. each channel) Bin 2x2

Ha

810 min (27 x 30 min. each channel) Bin 1x1

eXcalibrator RGB ratios are 1.00, 1.05 & 1.10

Software & Processing Notes

  • CCDSoft, CCDStack, PixInsight, Photoshop CS6.

  • eXcalibrator v5.0 for (g:r) color balancing, using 78 stars from the APASS database.

  • CCDBand-Aid to repair KAI-11000M vertical bars.

  • CCDStack to calibrate all sub exposures and create the RGB image.

  • PixInsight to register, normalize, data reject, combine the luminance sub exposures, gradient removal, non-linear stretching with HistogramTransformation and to create the LRGB image.

  • PhotoShop for the final touch-up.

Comment

North is to the top.

The Crab Nebula, located 6,500 light-years away, is the result of a star that was seen to explode in 1054 AD. This spectacular supernova explosion was recorded by Chinese and (quite probably) Anasazi Indian astronomers. The filaments are mysterious because they appear to have less mass than expelled in the original supernova and higher speed than expected from a free explosion. In the nebula's center lies a pulsar: a neutron star rotating 30 times a second.

Source: NASA APOD