This image shows comet C/2019 Y4 (ATLAS) as it continues to break up the closer it gets to the Sun. This is a single 600 second exposure with the mount’s movement matching the comet’s motion. Two primary fragments are obvious but I have convinced myself I can see at least one more bright spot trailing the other two in the comet’s tail.
C/2019 Y4 (ATLAS) [CV:1x600s]
I took advantage of a software capability I hadn’t used before to take this image. APCC (Astro-Physics Command Center) is software that sits in between the user and the AP mount, in this case an AP1600. It has the capability of using data generated by the JPL HORIZONS web based tool. That tool takes the orbital elements of an object and generates an ephemeris of the desired solar system object based on user specific parameters.
I use the tool due to its extreme accuracy. It is also convenient since JPL lists the PTO in its list of observatories. I had always used the output ephemeris manually before, printing out the table of data, reading the objects location at the current time and manually sending the mount to that location. This is the first time I had the software read the data directly and adjust the mounts tracking rates to match the comet. I am pretty sure this will not be the last time I use HORIZONS.