Celestial hemisphere:  Northern  ·  Constellation: Cygnus (Cyg)  ·  Contains:  Crescent Nebula  ·  NGC 6888
Crescent Nebula and spectrum of wolf-rayet star, 



    
        

            Remco Kemperman
Crescent Nebula and spectrum of wolf-rayet star
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Crescent Nebula and spectrum of wolf-rayet star

Crescent Nebula and spectrum of wolf-rayet star, 



    
        

            Remco Kemperman
Crescent Nebula and spectrum of wolf-rayet star
Powered byPixInsight

Crescent Nebula and spectrum of wolf-rayet star

Acquisition details

Dates:
July 15, 2021 ·  Aug. 13, 2021 ·  May 27, 2022
Frames:
Baader Planerarium Ha 6.5nm (CMOS optimized 36mm): 76×300(6h 20′) (gain: 1600.00) -15°C bin 1×1
Baader planetarium Oiii 6.5nm (CMOS optimized 36mm): 71×300(5h 55′) (gain: 1600.00) -15°C bin 1×1
Paton Hawksley Education Ltd Star Analyser 100: 30×120(1h) (gain: 1600.00) -15°C bin 1×1
Integration:
13h 15′
Darks:
30
Flats:
30
Flat darks:
30
Avg. Moon age:
12.41 days
Avg. Moon phase:
21.34%
Bortle Dark-Sky Scale:
6.00

Basic astrometry details

Astrometry.net job: 5899924

RA center: 20h12m06s.5

DEC center: +38°2132

Pixel scale: 1.405 arcsec/pixel

Orientation: 6.789 degrees

Field radius: 0.923 degrees

Resolution: 2566x3975

File size: 4.8 MB

Locations: Backyard Woerden, Woerden, Netherlands

Data source: Backyard

Description

The star in the middle nebula is Wolf rayet star WR136.[color=var(--lighterGrey)]It has expelled a lot of its outer layers allready. This is what makes the Crescent nebula. A lot of hydrogen of the star is allready gone. Which can be seen in the relatively week hydrogen emission lines in the star. [/color]Helium an nitrogen lines however , are stronger. We are looking at deeper layers of the star. And it is hot, 70.000 Kelvin! Wolf Rayet stars are the last stage of massive O-type stars before they go supernova. The star is allready instable and expelling its outer layers
the spectrum was taken with a staranalyzer gratingThe image with Ha and Oiii filters

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Crescent Nebula and spectrum of wolf-rayet star, 



    
        

            Remco Kemperman