Pluto 2015 August

I had never seen Pluto. I hunted for it once before without success after getting a 12-inch Newtonian in 1993, the first telescope of mine that had sufficient aperture and was up to the job. No luck though.

With the New Horizons probe fly-by last month it seemed I ought to make the effort again – now or never. Plus, it is slap bang between Xi1 and Xi2 Sagittarii, a clear signpost.

At mag. 14.3 Pluto should be easy in my half-metre ‘scope BUT its declination is minus 21 degrees. It has been sliding south since its discovery in 1930.  From Kent it can’t get any higher than 18 degrees, so down in all the atmospheric clag and Dover Harbour Board aurora.

Some sources, including Sky & Telescope, are still quoting it as mag 14.1 but that is out-of-date. I wonder if it is a hang-over from when Pluto was closer to perihelion in 1989.

Here is the view last night, 6 August 2015 through the Halton Arp Telescope at x260.

Pluto 2015 Aug 6

At first there was no sign. I watched the field for an hour or more up to south culmination at about 22h UT. There was a lot of cirrus wafting about so sometimes it was a struggle to see any stars at all. Eventually, on several occasions, the clouds retreated and there were the faint field stars, and there was Pluto. YAY!