View Full Version here: : viewing Sirius B
19-12-2011, 11:48 PM
I had my 12" dob out the other morning and saw Sirius B for the 1st time at 300x. It was surprisingly clear in the pre-dawn light. I thought I would do a comparison with night time viewing before posting. Tonight was the first cloud free viewing since that day, and I was again able to see Sirius B, but although it happened to be well away from the spider diffraction spikes it was much less obvious, with light shards from Sirius A overwhelming it much of the time. So for anyone who hasn't seen it yet, try an hour or so before sunrise. B is to the east of A, so it trails the main star.
22-12-2011, 09:10 PM
:thumbsup: Cool Andrew , I wont forget the 1st time I spotted B as well , in my 10 inch f/10 newt , but unlike you I seen it in the evening :) Twilight , bang:eyepop:! there it was after all those years of looking for it .
Thats a tick for you with many , many more to follow , especially with a 12 incher . A life time's worth of discoveries you have .
I wonder if the 1/2 light at twilights helps ? .as sirius is very bright .
22-12-2011, 10:01 PM
Well done guys, i am still trying, never seem to get quite the right conditions. Hartung in his books says that for most of us with modest objectives evening or dawn is the only time we are likely to see it. My biggest scope is only 8" so i think i will have to be pretty lucky.
08-01-2012, 09:10 AM
AN 8 INCH aperture should reveal the pup, also have a 120 ed refractor, no joy yet with either, although i seem to remember glimpsing him years ago in a 4 inch, maybe not ;) The pre dawn sounds a good idea, I often feel many objects reveal their best then.
08-01-2012, 06:15 PM
Each year will have this tough split be easier and easier although always tough due to how bright Sirius A is relative to B. It's spaced about 9.6 arcSec now so is not as difficult as it was in previous years.
Here is the spacing of A to B for this very active (in our lifetime) pair
1993 2.6 About the closest
2023 11.3 About the farthest
09-01-2012, 05:43 PM
i am sure i am not mistaken but in a recent AS&T or astronomy mag they said that rigels companion was about the same distance from its parent as sirius b is from its?
i saw rigels for the first time at christmas' new moon, but no way coud i sees sirius b
rigel was fantastic though
09-01-2012, 05:43 PM
by the way any tips for sirius b?
09-01-2012, 06:05 PM
:) A very clear and still early morning, looks to be tha best combination , and oh yes a good set of optics .
09-01-2012, 06:43 PM
Spacing now is over 9 arcSec so a better chance than in prior years.
Even so it helps to have best seeing possible and be patient and look for a long time. If you know which side of Sirius A it is on the place attention there and look for an irregular bump that does not flutter around as much as other seeing related changes to the Sirius A.
For a Dob or SCT you should really take care to collimate with extreme care and be sure your optics are completely cooled down (especially for SCT it can take an hour or more!). Don't just pop out the SCT and have a look, it will likely disappoint.
A 5-6" high end APO refractor is easier than a non-masked bigger Dob.
If you have a really big Dob (> 16") then use a circular cutout to convert that Dob to a wonderful achromatic better-than-glass scope. People generally use a big piece of cardboard with a very clean edged circular cutout that fits between 2 of the spider vanes for a dob of 16" or more.
As has been stated, look in the very best of seeing conditions you can get and by the way, you can have a moon out as long as it is a fair distance from the pair. Go for the best of seeing for best chance. See SkippySky for seeing predictions.
09-01-2012, 09:59 PM
To be honest. In my 12 inch dob. Splitting Sirius at them moment isn't that hard. I split it two weeks ago at about 114x magnification. Sirius was close to Zenith though. So less atmosphere to look through. Every time I take my telescope out and Sirius is in the sky I try and split it, so maybe its easier for me since I know what size object I'm looking for. Mind you on the same night I was able to spot stars E and F at 114x magnification in the trapezium in M42.
The worst however is when Sirius B is hiding in a diffraction spike. Its completely invisible when it is.
Good eyepieces and optics is what you really want.
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