22nd June 2009

Barnard's Star in Ophiuchus

Move the mouse over the picture to show the movement since the Digitized Sky Survey image was taken.

Barnard's Star moves at a rate of 10.3 arcseconds per year. By finding the positions of two fixed stars on the image it is possible to work out how many arcseconds the star has moved. My calculations indicate that the Digitised Sky Survey image was taken on the 27th May, 1991.

Update: I emailed the DSS people to ask if it was possible to find out the date that images were taken. Dr Brian McLean replied and said that the information was in the header if you download the image as a FITS file. I did this. The date given was 16th June 1991. Out by 20 days!