C/2020 P4-C?

[blakesphere]

Received a CalSky alert for hyperbolic comet C/2020 P4-C (SOHO). Supposed to be mag -1 or -2!? Anyone know about this? I've yet to dig into SSD and MPC...

[obrazell]

I suspect duff data from the MPC. They seem to be quite good at this lately. Looking at the MPC data it would seem they have bad values of h for all The P4 fragments

Owen

[theskyhound]

Every time I think that the MPC has finally gotten their act together, I find out that I'm wrong. Much of the most recent current comets data comes from another source. I am almost ready to release a new update and it will come with the ability to read comet data from a file other than the one you can download from the MPC. This should help people who want to keep up with comets as they are discovered, especially the very faint ones.

Looking into P/2020 P4 now.

[theskyhound]

Owen is correct that the MPC has the wrong magnitude numbers. Seiichi Yoshida has better magnitude parameters here:
http://www.aerith.net/comet/catalog/2020P4/2020P4.html

If you want to edit these yourself in ST4, open the Comets database. Double-click on each of the three comet components and enter these numbers for the magnitude parameters:

A h=14.0, g=4
B h=15.5, g=4
C h=15.5, g=4

[bigmasterdrago]

Thanks Greg. The MPC looks to be at least 9 recent discoveries behind. Very frustrating to add, edit, etc. like we had to do in the 1980s. There is a good bit of astro software out that does not allow the h & g to get edited.