Comet 103P Hartley
James Abbott reports on a comet current visiable in the night sky:
Comet 103P Hartley is now a fairly easy object although due to being large and diffuse, it needs a dark sky to see it well. It is just below Cassiopeia currently. There are several observing charts available on-line.
Last night (4th/5th October) using 10 x 50 binoculars I could see a coma 20 arc minutes in diameter (ie 2/3 the width of the full moon) with an integrated brightness of about mag 6.2.
Over the next month or so, Hartley will be well worth watching – comets can brighten, fade, develop tail structure, etc unpredictably and this one will pass close to the Earth in late October at just 0.12 AU, with perihelion being around the same time. It will be very well placed in the sky as it reaches perihelion just outside the Earth’s orbit – so we are looking at it facing in the opposite direction to the Sun.
The only spoiler (apart from the rains) will be the Moon late in October, but Hartley should still be near its brightest into November.