Quote:
What I can always see in any scope from 3"-25" is a ghost image of Sirius from one of the internal surfaces of the eyepiece, and at these powers I'm usually looking through a TV radian, so it's not like the eyepiece is especially bad. Unless people can confirm the correct separation and position angle of the pup, it's hard to be sure they haven't seen a ghost. Of course, my 41 year old eyes are a lot yellower than they were.
cheers,
Andrew.
|
Thanks Andrew for mentioning this ghost image. I had noticed this as well and it could easily be mistaken for a faint companion, especially on those using goto scope. If the drive is off or you shift the dec axis this ghost can move in the field relative to Sirius, so you clearly know it is not Sirius B. I would say that this ghost image accounts for many reports of detection.
When I get back east to my 130EDT Starfire, given some good conditions I will try again. If this scope cannot pick it up then I will write off all observations in scopes of less than 4". The 130 can pick out Enceladus against the disc of Saturn, so if any smaller scope can detect Sirius B, this one will.