I have spent many years looking for a comet from my home observatory. While I have found quite a few doing survey work for Catalina Sky Survey, nailing that "home" comet was still a high priority item for me. I finally found one on Sept. 30, 2024. This was a marginally bright comet moving through the Milky Way that I just beat ATLAS to. After running precovery searches in CSS data, it quickly became clear that this comet had recently gone from undetectable to an outburst within a short period of time, days or a week.
CBET announcing comet: http://www.cbat.eps.harvard.edu/iau/cbet/005400/CBET005457.txt
Image above shows it in G96 data the night after discovery. Very clearly a comet.
I continued to track the comet in CSS data after discovery and quickly realized that it was not meeting brightness expectations. Whereas it should have been increasing in brightness, it appeared to be decreasing.
Plotting the expected brightness curve from the orbit shows that the comet should have been increasing in brightness after discovery. There is a non-detection in G96 data from Sept 13th, 2024. The comet was not visible in G96 images to at least 22nd magnitude at this time. What is apparent from this plot is a massive outburst of the comet from undetectable to around magnitude 17 when discovered on Sept 30th.
A more narrow view of the observations shows the outburst and rapid fading more clearly
