Sirius A and B

[beka]

Hi All,

Encouraged by my image of Uranus and some of its moons some weeks back, I decided to take on the challenge of viewing and maybe imaging Sirius B with my CPC 1100 for the first time. At 9:00PM Sirius was at about 45 degrees - sky was completely clear with a limiting magnitude of about 4.5 and almost no wind. With an 8mm Baader Hyperion at 350X I was convinced that I could quite easily see a tiny spec between the flaring "spokes" of the main star. With the eyepiece pointed straight up I saw it to my lower right and estimated that it's position angle was thus roughly almost directly east (90 degrees). I checked this up on the Internet later and it seems correct for Sirius B. It's separation from the main star of around 10" (which I knew before) also seemed to be correct. I asked my 9 year old daughter and my wife to take a look (I asked them to look for a faint star close to the very bright star and tell me it's position) and both were in agreement with myself. Neither of them can be considered experienced observers :-) I then attempted to image the pair with my Sony SLT58 DSLR. I started at ISO 800 and took several images at each of 20, 10 and 5 seconds. Viewing these on my computer I was initially disappointed seeing nothing of Sirius B on the 20 and 10 second images, but  then felt I could see a bulge on the main star in the 5 sec images. I dropped the ISO to 400 and took images at 1 and 0.25 seconds. Below it one of the latter converted to PNG format from the RAW and cropped. No further processing was done. Hope you enjoy!

[John]

Nice report, description and photo

Your description is just how I see the "b" star (or "The Pup") with my 12" dobsonian at around 260x. The photo is similar.

When I've viewed it in with my undriven scope, the faint "b" star seems to follow Sirius A as it drifts across the field of view.

 

[michael.h.f.wilkinson]

Well spotted! Having Sirius at an altitude of 45 degrees is a luxury I don't have here. Your seeing must have been great for inexperienced observers to spot the pup. Having a few inches more aperture than my C8 cannot harm either. Maybe you could try more of a planetary imaging approach to catching the Pup, by making a short video (uncompressed if at all possible) and stacking this in AS!2. Might try that myself one of these days, if Sirius sticks its head over the parapet (trees behind our house)

[laudropb]

Very nice capture and interesting write up.

[beka]

On 1/20/2017 at 00:08, michael.h.f.wilkinson said:

Well spotted! Having Sirius at an altitude of 45 degrees is a luxury I don't have here. Your seeing must have been great for inexperienced observers to spot the pup. Having a few inches more aperture than my C8 cannot harm either. Maybe you could try more of a planetary imaging approach to catching the Pup, by making a short video (uncompressed if at all possible) and stacking this in AS!2. Might try that myself one of these days, if Sirius sticks its head over the parapet (trees behind our house)

Hi Michael,

Thanks for the suggestion. I have attempted this on planets some time back so I think I will give it a go. 

[ollypenrice]

A fascinating and original post.

Ollyt