Algol Loc: Georgia

What to do when the moon is out and interfering with astrophotography? Try imaging double stars. I became curious as to just how small of a separation I could get and tried smaller and smaller separations of double stars. The image is of the star Struve 300 in the constellation Triangulum. The bright image to the left is a much enlarged image of the star with a 10 second exposure, ISO 3200, 6-inch RC at f/9. The two dots to the right is the same star, same scale and same settings but with a 1 second exposure. The two stars are clearly separated. Data on the two stars are: magnitudes 7.89, 8.08 with a separation of 3.2 seconds of arc. It would be an easy double to split visually, photographically, well that's another story. To give you some idea of just how close these two stars appear in the sky, 3.2 seconds of arc is the same as three pennies lined up side by side and seen from a distance of 2-1/2 miles!!!!! The moon's apparent diameter of roughly 30 minutes of arc (or 1/2 degree) is equivalent to 1800 pennies lined up side by side.

Struve 300

CraigFair Loc: Santa Maria, CA.

Thank you Algol,
That's a great lesson in Astronomy.
Craig

Algol Loc: Georgia

Thank you CraigFair. Even after all these years I have been into astronomy, it never fails to astound me at some of the facts one can uncover.

Albuqshutterbug Loc: Albuquerque NM

That is one small pair of stars.
Very well done.
Lets see.. I can't see a penny 300 feet away much less 2.5 miles. ;)

Nikonian72 Loc: Chico CA

:thumbup: