The Return of Comet Longmore

Comet Longmore
Credit: The Liverpool Telescope

 2016 marks an unusual astronomical anniversary for the Astrophysics Research Institute: the return of Comet Longmore.

Comet Longmore is a so-called "short-period comet": a ball of dirty ice that follows an elongated path as it orbits around the Sun, only coming close enough to be visible for a few months each orbit - about every 7 years in the case of Longmore. Since short-period comets can take anywhere from a few years to a couple of centuries to complete each orbit, Longmore is a relatively quick one, but it is still rare visitor and it is not often that we get the opportunity to study it.

What makes it special to us here is that it was discovered in 1975 by Andrew Longmore, the father of LJMU astronomer Dr Steve Longmore.  Andrew remembers, "Comet Longmore was one of my earliest discoveries during my first ever research position, an astronomer at the UK Schmidt Telescope at Siding Spring Observatory, Australia ... [The discovery] involved manually scanning the plates using a small hand-held magnifier while they were mounted on a light table.”

Although the comet has returned to the inner Solar System near us and the Sun several times since 1975, this is the first time Steve has had a chance to get a good look at the bit of the Solar System named after his Dad. Since this represented such a rare opportunity, we made use of the power of the Liverpool Telescope. The unique robotic nature of the telescope makes it ideal to catch such fleeting events, and on the night of 21st May, a set of observations were taken that clearly show the fuzzy comet and its "tail" of dust and gas boiling off the surface and being blown off into space by the radiation of the Sun. Both Andrew and Steve are delighted with the observations, "I was absolutely delighted to have the chance to re-observe and actually see a part of our solar system that my dad had discovered decades ago, especially given the challenging observing conditions so close to mid-summer with the Moon quite full and at only a small angle from the comet!”

In the picture you may also notice a slight elongation of the stars in the field, this is due to the fact the telescope was tracking the comet as it continued on it’s orbit.

See you again in 7 years little comet!