Pluto in 1s

[Martin Meredith]

Following a discussion over the summer as to how short an exposure would be needed to capture Pluto with 'typical' kit, I had a recollection that I'd managed it some years ago in 1s but couldn't lay my hands on the evidence... Theoretically it should be possible with decent skies in sub-1s with an 8" f/4 scope and a sensitive mono guide camera with large pixels. So last night I had a go and sure enough, it is indeed possible to capture in 1s. I've marked the position by comparing with the DSS image at Aladin (see central region below). There does appear to be a star near to Pluto's position on the DSS but it is around mag 16 and not quite in the right place. The star to the right of Pluto has a GAIA g mag of 14.6, which is similar to the estimated 14.3 for Pluto.

Details on image. No darks/flats. North up. Taken through Baader C filter.

 

 

Looking at this sub, even with the relatively high read noise Lodestar X2 camera, I'm pretty sure it could be done in less, maybe as little as 0.25s. Why the rush? Well, I'm never going to be able to resolve surface details so the point source is about as good as it is going to get 😉

cheers

Martin

 

[maw lod qan]

Thanks, you give me hope!

I had wondered if my 8" would be enough with my simple Canon. Now to just get good enough at star hopping to locate the right place in the sky.

[Carbon Brush]

Amazing image. Two thoughts come to my mind.

First, a mag 14 object is going to defy discovery by accident. The search by Clyde Tombaugh was looking in a (mathematically) predicted location.

Second. Less than a hundred years after Pluto's discovery, after less than half an orbit around the sun, things have moved on so far that an amateur astronomer can see the object.

[Martin Meredith]

Thanks maw lod qan and Carbon Brush. Its worth adding that I am at around 43 degrees which helps a lot, and that Pluto was about 25 degrees above the horizon. Now is a good time to catch it though as it transits more or less when astronomical darkness is reached.

Martin

[Pete Presland]

It may not be a plant anymore, but that's a fine capture. It will always more important to me than all the other minor planets.

[Martin Meredith]

Thanks Pete; me too!

Just to confirm position and to check whether I could detect it in sub 1s, I was out last night again at around the same time as Pluto was transiting. Here's a comparison of positions showing movement from Monday to Thursday:

And here are 1s, 0.5s and 0.25s captures:

At 0.25s it was not visible on all subs -- maybe half of them. 

Martin

 

[orion25]

Great job, Martin. It's an accomplishment to image Pluto at all. At over 3 billion miles away, it's quite an enigma to find!

 

Cheers,

Reggie

[Stu]

Very nice Martin! Having just read the Chasing New Horizons book, I would love to have a go at spotting Pluto visually. Pretty challenging I'm sure, even from a dark site.

Skysafari has the position in exactly the same place, just as a matter of interest.