Well, it has been a fair few number of years since I've done one of these. Looking through some of my past observing diaries and also talking to a couple of friends about things has made me want to try and get back into this and keep a record of my more notable observing sessions.
To get to the topic. Ever since I started observing with a telescope - back in 2001 - I've always known about Sirius B and I quickly learned, from books and a few online resources at the time, that this double star is extremely challenging. Not only because of its very close proximity to its parent star (Sirius A) during points of its orbital period but mainly because of the sheer brightness of Sirius itself. For a double star it has a fairly likable separation and other stars of similar angular separations are not that challenging to split at medium magnifications. Even when B is at its most distant points in its orbit the star gets lots in the brightness of A and this is where the challenge lays in being able to visually observe this tantalisingly challenging double.
As a bit of a double star fan boy I have always wondered about the possibility of observing it and of course through out the years I have tried to, if only just for the humorous novelty of it or to see if you could get lucky.
As of a few years ago I knew that Sirius B would be reaching its most distant point in its orbit around A and would be at its best chance to obverse for the next five years, or there about, so I had been thinking about it now and again, to try and think how I could best observe it.
Thanks to a brilliant article a good friend sent to me from a magazine - possibly Sky at Night - it was about Sirius B, with very helpful diagrams and a fantastic bit of advice, which was, to use Iota Orionis as a ruler of distance from primary star to double, as to be able to judge where in Sirius As glare to look for B.
I have tried to look for it using this trick about three times since December but to no avail. I was using a 12" Orion UK Dob - with a figure of eight spider - and I was coming to the conclusion that what ever the scopes spider was doing to prevent defraction spikes on stars the stars do become blurry as more magnification was applied so I knew I wasn't going to get anywhere with that.
So we forward to yesterday - the 4th of January 2020 - and I knew the weather was going to be nice for the day with a good chance of clear, or at least partly, clear skies. This came to be true and by mid afternoon my thoughts were turning to Sirius again and knew I had to set up for another attempt, this time a bit more of a serious stab at it.
I decided on giving the refactor scope a go. It's as basic as they get for a refactor, just Bresser Messier 127L. I was considering the 10" Orion on the EQ6 but didn't want to be fussing with collimation in the freezing cold and the good possibility of another failed attempt but also because the moon was too bright to do any other good observing so Sirius was the only target of interest.
Evening came, it got dark, I got set up and after a very smooth and quick three star alignment my GOTO and tracking was excellent.
The equipment used was, as already said, the Bresser Messier 127L refactor, EQ6 Pro on the tripod.
17mm & 10mm Delos and 4.7mm Explore Scientific eyepieces as well as a 2x Tal barlow, along with my full selection of colour filters - yellow, green, blue and orange. Location was just the good old front garden.
The session went as follows,
I went straight onto Sirius to have an idea of how conditions were. Seeing was not great, the usual disco light show to expect at my latitude.
I then slewed to Iota Orionis to get that double into view and made my eyepiece selection base on how I was seeing the this double and I settled on the 4.7mm ES. This gave me a very comfortable 255x magnification. After spending a good few minutes taking in this view and getting a good visual memory of what I need to look for I slewed back to Sirius and just took in the view. The magnification was as such that the Fresnel rings created were the most dominant feature.
A few minutes in and I think something is there. I am starting to see the appearance of what I thought was the companion, then for a few moments it flickers in to view - due to a moment of improved seeing no doubt.
Trying to suppress excitement I decide to change eye piece. I changed to the 10mm Delos, the image is much sharper but the loss of magnification is too great so I put on the 2x Barlow and am at 250x now and the image is better than in the Explore Scientific, by a noticeable amount.Just a few moments of reaching focus I could spot it again and came through a bit clearer.
I went back inside to confer with images and the helpful graphic in the magazine and at this point I was certain I was seeing Sirius B.
The thrill and excitement of this was surging in me but I thought it wise to check again and this time I kept my eye on the eye piece for about 10-15 minutes. The seeing was fluctuating widely at times and it would vanish and then come back.
I next turned to the idea of trying colour filters, in the hope it would cut out some of Sirius A's glare.
I started with green, this wasn't bad, it cut out the glare a lot but made seeing 'B' more challenging, so I changed to yellow and this didn't do much for me at all. I then put on the blue and it was useless but made Sirius look striking.
I left the orange to last because I was thinking this would be the worst to try, well I couldn't have been more wrong!
When I got my eye to the eyepiece it was one of those moments where you just gasp in amazement. There is was, as plain and easy to see! I was in disbelief for a while as it looked too good but after checking and rechecking I had to allow myself to just believe it and let the feeling of pure joy take over and just soak in the beautiful sight.
I looked at this for about 10 minutes when my thought turned to wishing I could get an image to share and prove that I have seen it but not having any useful equipment I kind of gave up but then I just thought to myself "just try your bloody phone, there is nothing to loose", so I did get the phone and after some fussing around with getting the camera lens to line up with the eyepiece it bloody well appeared on the phone screen and so much better than I ever thought it would!
I took many photos and some came out stable enough so, below is the photo that I was able to take of exactly what I was seeing. Phone used is a Samsung Galaxy S8 and the image is raw with no processing of any kind, just cropped to centre the stars.
It's not the most thrilling astronomical image you'll see online but it's the best I could do and represents really well what I was observing.
Now that I know my orange filter really helps cut down the glare of Sirius A I am going to retry this using my 10" on the EQ6 Pro and get a second observation. I may even pull out my old laptop and black and white web cam to try and image it.
I started observing at 19:50 and when I was done it was past 22:10. It only felt like I was out there for 30 minutes and hardly spent any time observing this rewarding moment but I was clearly enjoying myself so much time just flew by.
After all was over I went back online to cross check with images and I came across this excellent drawing, of the view through a refactor back in 2010.
This perfectly illustrates the view I had at the eyepiece with the refraction rings being that pronounced when unfiltered and the dramatic reduction when using a filter.
All credit and copy right of this image belongs to "Harry Roberts" and was taken from Museum of Applied Arts and Sciences.
The weather for the foreseeable two weeks is looking abysmal so I am really hoping for a clear night before the month is over to get another try but with another five years to be able to see this at its easiest I am sure I will get more time to know this double star better.
