AstroBin saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing AstroBin without changing the browser settings, you grant us permission to store that information on your device.
I agreeImaging telescope or lens:Borg 90FL
Imaging camera:ZWO ASI 183MM Pro
Mount:Celestron AVX Mount
Guiding telescope or lens:Agena Astro 50mm f/3.9 Guidescope
Guiding camera:ASI224MC
Software:Stark Labs Nebulosity 4.2 , Digital Photo Professional , IDEIKI AstroPhotography Tool (APT)
Filters:Optolong 7nm Ha 2" , Astronomik 6nm OIII
Accessory:Borg 1.08X DG Multi-Flattener, #7108
Resolution: 3000x2000
Dates:Aug. 4, 2018 , Aug. 5, 2018
Frames:
Astronomik 6nm OIII: 24x300" (gain: 100.00) -15C bin 1x1
Optolong 7nm Ha 2": 24x300" (gain: 100.00) -15C bin 1x1
Integration: 4.0 hours
Darks: ~41
Flats: 0
Flat darks: 0
Bias: 0
Avg. Moon age: 22.39 days
Avg. Moon phase: 47.47%
Bortle Dark-Sky Scale: 4.00
Temperature: 22.00
Astrometry.net job: 2187435
RA center: 17h 58' 33"
DEC center: +66° 38' 2"
Pixel scale: 0.898 arcsec/pixel
Orientation: 178.121 degrees
Field radius: 0.450 degrees
Data source: Backyard
The Cat's Eye Nebula or Caldwell 6, NGC 6543, is a relatively bright planetary nebula in the northern constellation of Draco, discovered by William Herschel on February 15, 1786. Herschel compared the nebula’s appearance to that of the disk of an outer planet when seen through a small telescope, which is how planetary nebulae got their name.
It is 3,300 light years from Earth. The pulsations that formed the outer "rings" probably started 15,000 years ago and ceased about 1000 years ago, when the formation of the bright central part began. The nebula appears as a diffuse blue-green disk when viewed with small telescopes, which is the central portion only as t he outer portion is too faint for amateur telescopes.
The central progenitor star is an O7 Wolf-Rayet-type star, about 10,000 times brighter than of our Sun, but 35% smaller in diameter . The star has a temperature of about 80,000 K (compared to our sun's 6,000 K). It is losing around 20 trillion tons of mass per second in a fast stellar wind. The star is believed to have originally had a mass of around 5 times our sun. The stellar wind has a velocity of around 1,900 km/s.
The Cat’s Eye Nebula is expanding at a speed of 16.4 km/s. Its angular expansion rate is 3.457 mili-arc-seconds per year.
The nebula’s core has an apparent size of 20” and a high surface brightness.
Note that distant galaxy NGC 6552 (370 million light years) is also in the image, to the left of the cat's eye, and the brighter portion of the outer halo of the cat's eye is considered IC 4677.
Comments