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.