开云体育

Hi all,

I wanted to invite some discussion on this topic I've been wondering about for a bit: I don't think C/2024 M1 is actually a comet.

C/2024 M1 (ATLAS) was published as a comet back in July, with four reports of cometary activity from X07 (H. Sato, T. Yoshimoto, and T. Prystavski) and W88 (N. Paul) - ~0.25 and ~0.5-m telescopes. Meanwhile, my own simultaneous observations from X09 (0.43m) did not detect any sign of coma or tail even on extended exposures far outdoing the 15x50s (750s) exposure of N. Paul, the longest stack searching for cometary activity among the positives reported.

Similarly, no images that I've seen published by Seiichi Yoshida on aerith.net show even slight hints of coma or tail, even with significant SNR on the body. The 'comet's light curve has followed an asteroidal 5logr light curve from 8.6 AU from the Sun all the way through its 1.7 AU perihelion in October, as well as its peak magnitude of V=14 a few weeks ago.

I'm not sure what the three itelescope and one slooh observers saw, but I think I have to guess that they all made a mistake. Nothing I've seen firsthand (including the attached very high-SNR observation by a friend a few days ago) supports these claims, and I'm considering requesting the MPC to redesignate it as an A/ object.

~Sam