Gueri & Fred's astronomy
Sirius A and B
Like many people, I have try to observe Sirius's components. But each time a fail to observe it. When looking at the figures, the target seems easy but this is not as simple as it look.
source : sky map 7 and sky catalogue 2000.0 ed 1985
Actually, Sirius B is mostly hidden Sirius A's halo. And that why even is in theory this double could be split using a 60 mm refractor. But it's very difficult to separate the two stars. More over, for me, Sirius's maximum altitude is 25°.
After many unsuccessful observation, I have decided to try the same techniques I use for planetary imaging. I set up my refractor with a powerMate 5x and a HX516 camera ( with square pixel ). This configuration give me 0.5" per pixel.
I try several exposure. A too short, and Sirius B won't appears. A too long, and Sirius A will be too bright.
I had some results using 5x10-3s and 10-2 s. But 10-2s is better.
Date : December 26th 2004
Exposure : 10-2 s (single frame)
A 4x enlargement gives :
Using Astro-Art, it's possible to determine the separation between A and B : This separation is about 6.5" (±2")
All pictures are copyright Frederic Pertuisot and may not be reproduced without permission