Sirius B

[pgc hunter]

Just a short report of my observation of Sirius B on the 17th January 2011.

I was using the 12" dob. Seing was average, nothing special but not bad either. I've had luck on previous occasions using my 3.5mm and 5mm eyepieces, but never attempted lower magnifications. Started off with the 3.5mm (381x), and the pup was quite easy to see. Through the 5mm EP (267x) it proved no more difficult. Then I tried the 8mm (167x), with which the pup was still plainly visible, but Sirius' glare was starting to hinder observation, especially with the boiling effect of the seeing. Then I barlowed the 22mm EP for 121x, and the pup could still be just seen, but only occasionally in moments of steady seeing. Hard concentration was required, certainly no casual looks here! Decided to go one lower, so in goes the 13mm for 102x, and to my surprise, it could still be spotted, although very irregularly, and only in split second instances as the seeing did its dirty work. Anything lower obviously killed it completely, I'm surprised it can be picked up at this lower magnifications.

[Suzy]

I interesting! Thanks Sab. I always thought it was beyond me at the moment as I'm fairly new to observing and have heard this is tricky to get. This gives me hope with useful information to help me.
I've heard this Sirius B (the pup) gets easier to see when it comes out at certain times (?), is now the time that is good to see it? And how often are the times of viewing it? Sorry about so many questions, learning here...;)

[barx1963]

The Pup at 102!!!:eyepop:
Sab you are the man;)

[Brian W]

Suzy a couple of weeks back I caught the pup at 94x in my 8" Lightbridge. If I can do it anyone can. Now mind, when I slipped in my 2.5mm it was much more pronounced but certainly more fuzzy. (not a great night).
Brian

[AstroJunk]

Sirius B is currently at 90 degrees PA - thats due East of Sirius and at a separation of over 10 arc seconds which is now quite wide. Its easier to see when you know where to look!

If Sirius is on the meridian, it will be on the right in an SCT, the left on a newt if i'm not mistaken. If you are not using a driven telescope, let the star drift for a while - the angle it drifts marks the e-w line for your scope.

http://www.youtube.com/watch?v=K9m5MW5HMl4 &

http://www.youtube.com/watch?v=lKwSdrTWeJM

I have been watching the two move apart for that past few years but have to admit not having looked visually yet this year.

Well done all for spotting it its one of the toughest challenges out there :thumbsup:

[ballaratdragons]

I might be way off, but would it be slightly easier to see the pup during daylight hours?

The few times I have observed stars in daylight they are more pinpoint and definitely not as glaring. Maybe worth a try.

[AstroJunk]

Thats an interesting thought, but I believe that the background sky magnitude is around 4 (Willing to stand corrected on the actual number), but even so, the Pup is just too dim.

It could be worth observing it during the twilight transition though, there could be a perfect moment...

[mozzie]

wow some interesting information thanks all!!! i tried a few years back with no luck now seems like the go........

[pgc hunter]

Hey Suzy, you are a shoe-in with the 10" scope. You'll need atleast average seeing, wait for Sirius to be as high as possible, and pump up the power. The pup is directly east of Sirius, the seperation is about 9" IIRC. Note the direction Sirius drifts across the field, and look for the pup directly "behind" it (trailing it). It'll show up as a tiny pip of light, but make sure you don't get fooled by reflections of Sirius itself caused by the glass elements in your eyepieces, as these can appear suprisingly like the little dog itself!




Don't think the pup is visible in daylight. Just too dim it would seem. Astrojunk's idea of a twilight hunt sounds interesting and might actually be superior to full darkness, much like when observing fine detail on Jupiter. Haven't heard any reports of anyone attempting a twilight observation, so I'm keen to try it if the opportunity presents itself.



Cheers mate! :D

[ballaratdragons]

Yes, exactly. I don't mean go looking for it in broad daylight on a sunny day :lol:

All my daytime observations have been early twilight. At Sunset and just after :thumbsup:
Still light but not bright.

P.S. About right now would be perfect!

[AstroJunk]

Not in Cloudy Qld :(

[CometGuy]

Since I got my new 12" Scope I believe I have been able to see Sirius B twice. On both occasions it was not particularly easy, but to be honest I was expecting it to be more challenging than what it was. I think the increasing separation between the 2 stars in recent years is helping a lot with visibility.

Ken if you try just after sunset you should be able to see it.

Anyway here is a sketch of roughly what I saw on Feb 4, 2011, at 375x.

Terry

[AstroJunk]

Sirius is notorious for creating false images in eyepieces. To confirm a result you really must know what 10 arc seconds is in your eyepiece.

have a look at the this page: http://www.astropix.com/HTML/B_WINTER/TRAPEZ.HTM the diagram of the trapezium shows the distances between stars - so we are talking the distance between a and b.

Then make absolutely sure it is in the correct position (90 degrees east of north)

If it isn't very hard indeed, it isn't the pup!

[CometGuy]

Hi Jonathan,

I'm quite sure of this observation. I checked PA (using the drift method) and comparision with the Rigel suggested the angular separation was correct as well.

With regard to false images, the one thing that makes discount this was the fact that companion moved with Sirius across the field. It kept its position relative to Sirius, and a reflection would not tend to do this.

Good seeing I think plays a big part, as the slightest amount of fuzziness will obscure the star within the glare of Sirius. Also my scope is very new and the eyepieces were cleaned prior to observation, so scattered light was minimised.

I should also say I have tried to split Sirius for many years and had never succeeded.

Terry

[AstroJunk]

Good work Terry, and you remind me of another important thing to do when looking at Sirius - go check another bright star that such as rigel or canopus and look for reflections too.

[ballaratdragons]

I spent a couple of hours experimenting with my Samsung AstroVideo camera today to place a small mask in the live feed so I can mask Sirius out and video the Pup, and typical! Thunderstorms :rolleyes:

Here is a Screen Grab of how it works on my Lounge-room ceiling.
I can make the mask any size I want, right down to 1 pixel x 1 pixel, and move it to any location in the FOV.
Only thing I can't do is make it round.

[pgc hunter]

Looking at that pic makes me realise how hard the G and H components of the trapezium are. The E and F are ludicrously easy, so after Sirius B the G/H is my next challenge.

[AstroJunk]

You are beginning to sound like a true SDM owner now :lol: The joy of owning a top quality mirror :thumbsup:

[pgc hunter]

lol I never found the E/F components to be any big deal and can split them at 80x, and even here it's more my own astigmatism that's the limiting factor.