That's consistent with my initial crude estimate this morning of -0.5 (measured against Mercury earlier at a similar airmass). The comet's easy visibility is because its coma is so compact, giving it a very high surface brightness now already comparable to C/2023 A3 at its peak.
Qicheng
On Saturday, January 11, 2025 at 11:20:52 a.m. MST, Nick James <comets@...> wrote:
Maik,
Good luck tomorrow. I know you are very experienced but be careful. I'm
only risking a camera, not my eyes!
I've processed the full video now and the result is here:
I've tried to estimate the magnitude by measuring the intensity in a 40
arcsec diameter aperture and comparing it to a video of Venus taken just
before the comet observation using the same settings. Assuming Venus is
-4.6 and using a correction of 1.0 mag for differential altitude (Venus
was at 29 deg, the comet at 10 deg) I get -0.8. That doesn't really seem
bright enough given how prominent the comet is on the image but that is
what I get!
Nick.
On 11/01/2025 15:15, Maik Meyer wrote:
> Nick,
>
> this is really great, great images, thank you. I might try it visually
> tomorrow as we have sunny skies predicted. Should gain maybe 2 mag in
> the next 24-48 hours.
>
> Maik
