At last, a clearer early morning sky to observe our 'alien visitor'. So as not to make it too easy, my dew shield has decided to retire and the anti-dewing heater was struggling to keep the corrector plate clear. Quite a display of hoar frost on the C11 tube and its finder.

Not as transparent as I wanted, but enough stars in the field to obtain some astrometry and photometry of 3I. Its motion was measured to be 0.03"/sec in RA and 0.01"/sec in Dec, confirming the sky motion of 1.96"/min in the MPC ephemeris. Its measured positions (submitted to the MPC) are in close agreement with its computed orbit - no sign of any non-gravitational effects from its 'impulse or warp drives' - and no sign of any 'Klingons on the starboard bow'.

G mag estimates using an 18 arcsec diameter aperture were between 10.1 and 10.8, with 10.7 being my favoured estimate.

Note - it's difficult to find the correct entry for this comet when selecting 'Objects in image'. After several minutes' searching I found '0003I', its MPC code.

(Update Nov 22) - MPC has updated its list of observations of 3I. I downloaded the txt file, ran it through Find_Orb and I got these residuals in RA and Dec

251121 Z92  .78+  .76+    
251121 Z92  .45+  .16+    
251121 Z92  .56+  .39+    
251121 Z92  .77+  .52+    
251121 Z92  .78+  .56+    

Find_Orb's mean astrometric residual from 4264 observations is 0".59. Further confirmation that astronomers know the comet's orbit to high accuracy.