Monitoring the evolution of comet 96P/Machholz 1 from its lightcurve

One of SOHO's most surprising comet-related discoveries is the existence of groups of short period comets on low perihelion distance orbits. Two of these groups, the Marsden and Kracht groups, are dynamically related to comet 96P/Machholz 1, an enigmatic object with a perihelion distance of 0.12 AU that makes it unobservable by most Earth-based telescopes around perihelion. Comet 96P has transited the SOHO fields of view during all five of its perihelion passages since 1996, and several faint fragments were observed accompanying it during its 2012 and 2017 apparitions. We report on our analysis of 96P's SOHO lightcurve, its secular evolution over the last 20 years, and on the evidence of ongoing fragmentation that might have produced the new fragments. We also report on our ground-based efforts to characterize 96P using the 4.1-m SOAR telescope. We observed 96P prior to perihelion in July 2017 and have post-perihelion observations scheduled for June and July 2018. This work benefited from discussions with the international team "The Science of Near-Sun Comets" led by G. Jones at ISSI (International Space Science Institute) in Bern, Switzerland in 2014-2015. NE, MMK, KB, and MSPK were supported by NASA Near Earth Object Observations grant NNX17AK15G.