Rigel also has a close companion, with almost the same separation as Sirius from Sirius B. However
Rigel and its companion are not as widely separated in magnitude and this is a much
easier double to observe.
I found the Rigel pair fairly easily, but it could be missed if you are not aware it has
a companion star. As I aligned the scope I checked for doubles on a few other stars - noting Polaris'
quite faint companion well separated from it.
Sirius was approaching the Meridian (the East/West border) due South and so was moving towards its
highest and best position for observation. Even so it would not climb above about 35 degrees in altitude.
I used a 4.3mm W70 Antares eyepiece for 186x on my 800mm FL 8" Newtonian. Sirius sparkled but was a little
muted by the thin cloud that was affecting its appearance on and off.
I was not seeing Sirius B and had intentionally not looked up its position so as not to cloud my judgement on
detecting it. About 40 minutes into observing, for just a few seconds, a fleck of light persisted very close
to Sirius. I moved my eye position around to try to confirm it. But after about only 5 seconds it was gone.
There were numerous annoying reflections in the eyepiece which had to be discounted.
I cannot blame the eyepiece for this as a very bright street light bores almost directly down the scope tube
when I'm looking South. Despite an OTA that extends well in front of the focuser and a 2 foot long Dew Shield,
the light still spills well into the scope tube.
The Scope had tracked Sirius well past the meridian and the motor housings were close to touching. I broke off
the pursuit for now. I attached the camera and took a few test images of The Pleiades to check
for star quality.
I then went back to first Rigel and then Sirius to see if I could pick up the elusive Sirius B on my DSLR.
After that I took another 20 minutes using 372x on Sirius to try to split its companion. I made a drawing of
the position of another possible candidate that seemed to be flitting in and out of view just above a
diffraction spike, but later after working out its position angle, I ruled it out.
Rigel with its companion hiding in the lower
diffraction spike. About 20 minutes earlier
it was easier to see visually because of cloud
Sirius and Yes, Sirius B, at the 10 O'clock position
The white halo is a result of thin high cloud which
kept chaing the appearance of Sirius
Rigel and its companion, perhaps a little easier to see
with the image inverted.
Sirius and Sirius B (again at 10 O'clock)
I confirmed the star field and Sirius B's
position with an image from
An enjoyable challenge. Although I did not see Sirius B visually, I am pleased to photograph the elusive 'Pup'
as its called. Also having knowlege of its appearance I think will make it just a shade easier to
detect visually under more transparent skies.