Hunting for the Pup... no luck

[Nik271]

The weather forecast was for clear skies this morning and on a whim I decided I will try for the elusive Sirius B since these years the separation is as large as possible: almost 11''.

Sirius transits the meridian at 6:30am when its 21 degrees high - as good as it gets from here. I went outside at 6am and there were some high clouds but the southern sky was clear. Unfortunately Sirius itself was twinkling and I knew it was going to be a mission impossible.

I used 9mm with my Skymax 180 giving 300x magnification. As I feared Sirius was a blob, dancing in rainbow colours and no sign of the Pup. I tried averted vision, moving Sirius just outside the FOV but nothing helped. Oh well... 

I wanted to make sure its not the optics, so I pointed at Rigel and saw the companion easily: a pale blue dot southwest of the primary, well separated, I think 10''. The companion of Rigel is magnitude 7, while Sirius B is 8.4 and lower in altitude so it's bound to be much harder. Well, I was up at 6:30am on a Sunday so decided to have some fun anyway and aimed for Alnitak. Last winter I tried repeatedly to split it with a Skymax 127 but never could. Today it was 'almost' easy: I had to wait for moments of good seeing and then it was visible as a yellow dot very close and south of the primary. Nice!

It was getting light but the moon was almost overhead and looked clear. Using 300x I could clearly see the bow of Sinus Iridum and also some shadows on the floor or Aristarchus and Vallis Schroteri next to it. Definitely worth getting up early on Sunday!

Further south the crater Gassendi was very nice with its central peaks. I could see a long line to the east it. When I came back I checked the Lunar Orbiter map to identify it - it was Rimae Mersennius. 

So I didn't see the Pup but still I had a good observing session. Very happy. Obviously have to try harder for the Pup....

 

Clear skies!

 

Nikolay

 

 

 

 

 

 

 

Edited October 11, 2020 by Nik271

[markse68]

Yay it’s pup season nearly  I waited for Sirius to clear the trees- about 3am i think to have my first attempt last night too- of course so low it was a waste of time- a set of dancing traffic lights. But I’ve got an ADC this year and really hopeful it might help- and it did! I had to wind it to full 4deg prismness but it tamed sirius to a dancing brilliant white thing. Great! Still no pup though and clouds swept across the sky, I was tired and freezing so not to be.

Good luck with the pup hunting Nikolay 

Mark

[John]

Nice report !

It took me ages to find a combination that would split Sirius. In the end my 12 inch dob plus a 6mm ortho eyepiece did it. Since then I've manged to split it lots of times (easier after the first time like most things !) with scopes down to 100mm.

I generally find that I need to use 250x or so to get the split and you don't see it like a normal double star - the Pup star glimmers out from from the glare that surrounds Sirius, sometimes only popping into view now and then.

Your scope and eyepiece selection makes sense - you just need to keep at it and when the seeing is decent, it will come though.

The separation is similar to Rigel but the brightness difference is so much more and of course it's low down from the UK.

Folks who observe where Sirius is higher in the sky wonder what all the fuss is about I think !

 

[alex_stars]

Thanks @Nik271 for the nice report. Great reminder to have the Pup on the radar of things to observe.

The other day I was imaging Mars and used Mesarthim (Gamma Ari and Gamma 1 Ari) to focus my Mak and I had no problems resolving the two. They are 7.5" apart. Sirius B should be 11.2" away from Sirius A so I think it really is the time to hunt for the Pup.

Looking forward to read more reports during the season.

Clear Skies.

 

[John]

This is a sketch I made of Sirius and the Pup star showing how it appeared though the eyepiece. As I said, it's not quite like resolving other double stars:

 

 

Edited October 11, 2020 by John

[Nik271]

Thanks, John, the sketch is very helpful! I had no problem seeing the further stars, so it's really about seeing through the glare of the primary. Knowing where to look makes it much easier.

[John]

1 minute ago, Nik271 said:

Thanks, John, the sketch is very helpful! I had no problem seeing the further stars, so it's really about seeing through the glare of the primary. Knowing where to look makes it much easier.

No problem.

The view is the newtonian one so S at the top and W to the left.

The Pup star trails Sirius as it drifts across an undriven field of view.

[Barry-W-Fenner]

Nice report Nikolay, it's sounds like you had an enjoyable session at the eye piece. I am yet to view the pup aswell. Hopefully this winter with the 12" dob and 6.5mm Morpheus combo!