Barnard's Star

[Martin Meredith]

Although I normally post in the video section this particular project has required a year's worth of images (albeit just two, totalling 1 minute exposure), so can hardly be described as near real-time observing ;-)

In 1916 E.E. Barnard wrote an article entitled "A small star with large proper-motion", and since then magnitude 9.5 variable star V2500 Ophiuchi has been better known as Barnard's Star. It has the largest proper motion of any star, at 10.4 arcseconds per year.

On a whim last year I decided to take a quick (30s) shot of it using a StellarVue Nighthawk 80mm f6 achromat combined with a SX Lodestar guide cam. This combination has a resolution of 3.52 arcseconds per pixel, so in theory the annual motion of Barnard's Star ought to be detectable. Last night I took another shot with the same equipment.

Here's the 2014 image

Note the handy v-shaped asterism if you're trying to locate this star.

Here's the 2015 image from last night:

Try as I might, I couldn't match the poor quality of the 2014 image (focusing, seeing, presence of a diagonal, experience, who knows?). Still, by choosing two alignment stars (other than Barnard's  ) I was able to produce a combined image using Nebulosity, and this is it (cropped, flipped and rotated). The relentless motion of the star in the direction of the arrow (approximately northwards) is indeed apparent in the combined image as a shift in the centre of the star.

Coincidentally, the centenary of Barnard's discovery is next year (June 3rd as far as I can gather), so it might be an interesting project to take a capture now and again in 2016. The combination I used was pretty low-end and almost any kit will do better than my fairly lousy attempt.

cheers

Martin

[WaveSoarer]

That's brilliant. A very nice project to keep adding more images to.

[Martin Meredith]

Thanks WaveSoarer. I intend to take a shot with my Quattro 8" this year which has somewhat better resolution and tighter stars, so at least by next year I can get a decent separation and no CA...

Martin