I've just updated the lightcurve with the latest observations. The
magnitude continues to fade in a 9 arcsec aperture. It is now around
12.4 having reached 12.1 in mid April when the phase angle was 3 degrees.

Nick.

On 03/05/2024 07:14, Nick James wrote:
> Morning all,
>
> Our latest C/2023 A3 lightcurves are here:
>
> https://www.nickdjames.com/Comets/2024/2023A3_lightcurve_9arcsec.png
> https://www.nickdjames.com/Comets/2024/2023A3_lightcurve_9arcsec_1.png
>
> You may need to refresh your browser to get the latest version.
>
> A number of people have noted the recent drop in brightness and this has
> been discussed on the comets-ml mailing list. Qicheng Zhang has pointed
> ut that this is probably a phase angle effect. In mid-April the comet
> passed through a very low phase angle and the brightness peak was
> probably due to the opposition effect since the comet appears to be very
> dusty. If that is the case we should start to see the comet getting
> brighter soon.
>
> The comets-ml discussion is here:
>
> https://groups.io/g/comets-ml/topic/c_2023_a3_showing_brightness/105847786
>
> This shows how useful the standardised photometry is. Please consider
> observing this comet using the method outlined here:
>
> https://britastro.org/section_news_item/12p-pons-brooks-observing-campaign
>
> The fact that the comet appears to be very dusty is encouraging for the
> expected performance next October.
>
> Nick.
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