2025f2 20250422 dbartlett

 
C/2025 F2 SWAN 2025_Apr_22 050640local
 
 
 
Notes:
 
 
 

    Comet appeared fainter than any previous morning. 
    Increased twilight and still present moonlight. 
    Imaged from 3 degrees to 9 degrees above local horizon. 
    Background gradients present in images due to horizon. 
    Comet aligned w stars  
    Integrated w median combination  
    No rejection & JPEG Full resolution @ highly cropped. 
    SPCC color calibrated for truest color in non inverted images. 
    All cropped images have standardized background (brightness)From April19 onward. 

 
 
 
No ASTROBIN post
 
 
 
Observational details:
Backyard setup
scope: C14 D = 356mm; fl =729mm; F# 2
camera: asi 6200mcP
exposure: 25 x15 sec
Seeing: 4/5 Transparency: 8/10 Seeing - Heavy Twilight, Low Waning Crescent Moonlight
Observer: DEBartlett
Location: June Lake, California, USA
 

Image Info (Cropped Closeup ):
Projection ............... Gnomonic
Projection origin ........ [1272.809365 970.427857] px -> [RA:  1 38 39.360  Dec: +35 04 45.79]
Resolution ............... 1.070 arcsec/px
Rotation ................. 36.907 deg
Reference system ......... ICRS
Observation start time ... 2025-04-22 11:58:16 UTC
Observation end time ..... 2025-04-22 12:13:52 UTC
Geodetic coordinates ..... 119 04 46 W  37 46 51 N  2434 m
Focal distance ........... 724.90 mm
Pixel size ............... 3.76 um
Field of view ............ 45' 23.9" x 34' 36.6"
Image center ............. RA:  1 38 39.359  Dec: +35 04 45.79  ex: +0.022097 px  ey: +0.010099 px
Image bounds:
   top-left .............. RA:  1 40 58.748  Dec: +35 04 52.55  ex: -1.135896 px  ey: -1.103893 px
   top-right ............. RA:  1 37 59.539  Dec: +35 32 12.20  ex: +0.028088 px  ey: -1.115450 px
   bottom-left ........... RA:  1 39 18.519  Dec: +34 37 21.18  ex: -1.642507 px  ey: +1.014150 px
   bottom-right .......... RA:  1 36 1