220p 20260826 dbartlett

 

_220P_McNaught_TandemRASA11s_asi6200mmP_asi6200mcP_54x120sec_20260826_050426_local_JuneLake_California_USA_DEBartlett
 

 
 

Comet 220P/ McNaught's Final Night, Calling it Quits Due to Moonlight, August 26 2026
 

 
 

ASTROBIN-Full Resolution, animation and other Goodies:
 

https://app.astrobin.com/i/5lh1qo?r=0
 

 
 

Project Notes:
 

    Final night! 
    Moonlight interference with only about 20 minutes of moon-lessness and darkness prior to morning twilight.  
    Started imaging early, as the moon set. 
    Reduced the exposures to 120 seconds to avoid oversaturation of the photo sites. 
    Comet dramatically thinner and longer in final image. 
    Tail measured at an apparent length at 75.9 arc minutes and brightness of the comet measured at magnitude of 10.6. 
    Considerable dust and/or IFN in the FOV. 
    A total of 108 minutes of useable total integration time from the twin RASAs. 
    Color appears subdued. 
    As usual, color calibration was performed with PixInsight's SpectrometricColorCalibration process using a white balance of the spectral class of our sun as reference.  Ideally this process lends to a more true rendition of a comet/nebula color however saturation of colors is the processor's choice. Ref: https://pixinsight.com/examples/C2022-E3-ZTF/ 

 

 
 

 
 

Observational details:
 

    Backyard setup 
    2xscopes Tandem: RASA11 D = 279mm; fl =620mm; F# 2.2 
    camera: asi6200mmP and asi6200mcP 
    Seeing: 4/5  
    Transparency: 7.5/10 some moonlight 
    Observer: DEBartlett 
    Location: June Lake, California, USA 

 

 
 

Image Info:
 

(All images processed solely using PixInsight and Comet Photometry Tycho-Tracker)
 

    Resampled 2x2 
    Acquisition...............54x120sec total 
    Resolution ............... 2.501 arcsec/px 
    Rotation ................. -2.386 deg 
    Field of view ............ 2d 33' 44.3" x 1d 38' 0.3" 
    Image center ............. RA: 3 09 35.605 Dec: +9 06 19.66 

 

 
 

220P (McNaught)
 

ICQ line:
 

IIIYYYYMnL YYYY MM DD.DD eM/mm.m:r AAA.ATF/xxxx /dd.ddnDC /t.ttmANG ICQ XX*OBSxxf InT APERTURcamchip SFW C ## u.uu xx.x PIXELSIZE
 

220 2026 08 26.49 C 10.6 AR 28.0T 2C720 2.2 75.9m253 ICQ XX BARaeI a120C 2.17mZCP IMX TYT 0 U9*0.13 10.7 2.5s 2.5 Location: June Lake Overlook (MPC U66); Comment: Comet Alt. 57.7
 

 
 

COD U66
 

OBS
 

CATALOG: ATLAS2 - BAND: r (Sun Mag=-26.93)
 

 
 

 10x10 20x20 30x30 40x40 50x50 60x60 RSR FC COD
 

COMET UTC +/- +/- +/- +/- +/- +/- N FWHM CAT
 

------------ ------------------- ----- ----- ----- ----- ----- ----- ---- ---- ---
 

220P 26/08/2026 11:43:27 13.82 12.85 12.34 11.95 11.68 11.48 66.5 17.4 U66
 

220P 26/08/2026 11:43:27* 0.13 0.13 0.13 0.13 0.13 0.13 31 17.8 ATL
 

 
 

 AFRHO LOG
 

COMET UTC DELTA r AP " MAG RSR CM +/- AFRHO OBS
 

------------ ------------------- ----- ----- ----- ----- --- ----- ---- ----- ---
 

220P 26/08/2026 11:43:27 1.15 1.71 24.02 12.61 66 525 123 2.721 U66
 

 
 
   
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