Comet C/2015 F4 Jacques near the galaxies PGC 64456 and PGC 64450 as seen from the Siding Spring Observatory at 2:00 am local time on April 18. The rectangle is the field of view of T9. Click to embiggen.
Denis Denisenko on comets-ml has alerted us to a challenging but interesting imaging opportunity.
Comet C/2015 F4 Jacques comes within 4' of galaxy IC 4991 (PGC 64450 mag ) and even closer to the smaller and fainter PGC 64456 (mag 14.3) on April 17th at about 16h UT. This translates to 2:00 am on the 18th at the SSO scopes.
The comet is in Saggitarius, and is best imaged from the SSO scopes, the observational window runs from around 1 am on the 18th to astronomical twilight on the 18th at just after 5:00 am.
Currently magnitude 15.7, you will need fairly long exposures to bring out the comet, so not smearing the galaxies will prove a challenge if you are tracking on the comet. There are other galaxies so a bit of composition off the comet may be worthwhile.
The MPC one line ephemeris is:
CK15F040 2015 08 09.7260 1.679893 1.000000 34.4654 286.4132 48.3598 20150627 11.0 4.0 C/2015 F4 (Jacques)