Hemisphere:  Northern  ·  Constellation: Lacerta (Lac)  ·  Contains:  KP Lac  ·  NGC 7245  ·  TYC3982-1275-1  ·  TYC3982-1380-1  ·  TYC3982-1389-1  ·  TYC3982-1560-1  ·  TYC3982-2067-1  ·  TYC3982-21-1  ·  TYC3982-216-1  ·  TYC3982-2812-1  ·  TYC3982-3048-1  ·  TYC3982-3270-1  ·  TYC3982-612-1  ·  TYC3982-621-1  ·  TYC3982-69-1  ·  TYC3982-726-1  ·  TYC3982-822-1  ·  TYC3982-867-1  ·  TYC3986-120-1  ·  TYC3986-3129-1  ·  TYC3986-3239-1  ·  TYC3986-3347-1  ·  TYC3986-3381-1  ·  TYC3986-3432-1  ·  TYC3986-3470-1  ·  TYC3986-3482-1  ·  TYC3986-366-1  ·  TYC3986-381-1  ·  TYC3986-486-1  ·  TYC3986-528-1  ·  And 11 more.
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Another double cluster, NGC7245 and King 9, 



    
        

            lowenthalm
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Another double cluster, NGC7245 and King 9

Getting plate-solving status, please wait...
Another double cluster, NGC7245 and King 9, 



    
        

            lowenthalm
Powered byPixInsight

Another double cluster, NGC7245 and King 9

Imaging Telescopes Or Lenses
Orion Skyquest xx16g Skyquest xx16g
Imaging Cameras
ZWO ASI294MC PRO ASI294MC PRO
Filters
ZWO IR Cut Filter ZWO IR/UV Cut Filter
Accessories
Explore Scientific HR Coma Corrector
Software
SharpCap 3.2 · Fitswork4 Fitswork 4.4.7

Acquisition details

Dates:
Aug. 27, 2021
Frames:
3x240" (12')
Integration:
12'
Avg. Moon age:
19.64 days
Avg. Moon phase:
75.48%

RA center: 22h15m10s.110

DEC center: +54°2154.30

Pixel scale: 0.758 arcsec/pixel

Orientation: -104.075 degrees

Field radius: 0.287 degrees

More info:Open 

Resolution: 2267x1519

Locations: Home, Vancouver, Washington, United States

Data source: Backyard

Description

So I have been searching out "other" double clusters and recently found this one in Cygnus. I like the contrast in colors and star density.

The larger, composed of bright blue-white stars is NGC7245, while the dimmer smaller cluster is King 9. Gaia DR2 data parallax data puts NGC7245 at 13,800 light years away from us and King 9 at around 21,000 light years distant. The clusters each clearly have some scattered outlying members, but when I estimated the size by measuring the diameter of the group of stars that were clearly members of each, I got 4.5 arc minutes and  3 arc minutes, which given the distances both are about 18 to 19 light years across!

Each cluster has very different types of stars. The yellowish hue of the more distant King 9 stars probably is in part caused by reddening from additional interstellar dust. When I tried to estimate the absolute magnitudes of the stars from the Gaia data, it looked like the NGC7245 were probably mostly bright A stars, which look the way an A star should, but the King 9 stars seemed to be about 1/3 the as bright, maybe making them cooler A or F stars, but with colors too young too yellow for that type of star. So again, looks like a lot of extra dust between us and King 9.

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Another double cluster, NGC7245 and King 9, 



    
        

            lowenthalm