Sirius and the Pup - April 2008

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BobSikes
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Sirius and the Pup - April 2008

Unread post by BobSikes »

A Serious Challange
  • With Summer coming fast, Sirius is sinking into the Western Horizon early in the evening. Let's see if we can all spot this very bright and close star before it's departs from view. Post a description of what you see when you view it naked eye, with binoculars or with a scope. For extra credit, see if you can spot "The Pub", the Dog Star's companion.
Rating:
Sirius: Easy -- The brightest star in the sky should be a cinch if you look SW early enough, before 9pm. If its bright and moves it's an airplane otherwise the Dog Star is most likely what you see. Newbies should identify the constellation to the right (N) that the Dog Star dutifully follows into the West. For more info http://en.wikipedia.org/wiki/Sirius
Sirius B, the Pup: Very Difficult -- If you have a sharp scope and a know a few tricks, it's now possible to spot the companion star of Sirius. While bright enough to see even a small scope, the glare of Sirius makes this a difficult double even at maximum separation. For some hints on how to spot it, try http://www.cloudynights.com/item.php?item_id=1387
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BobSikes
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Sirius before Dark - can you beat me?

Unread post by BobSikes »

Ok, I guess I’ll get this going. I saw Sirius this evening at 7:47 pm. It was flickering like mad, about 25 degrees up and in the Southwest. Very easy to see naked eye. Also, a bit further to the south and about 50 degrees up was dimmer Procyon. Big Dog and Little Dog.

So, anyone able to do better? I wonder if anyone (including me) can see Sirius earlier that 7:47pm. Naked eye, binocs or scopes. Who can see it first? Post away :!:
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BobSikes
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Come on you Young ASSNEs!

Unread post by BobSikes »

A New ASSNE Record for Sirius Spotting

This evening I spotted the brightest star in the sky (North and South hemispheres I now think) naked eye at 7:37:15 EDT (atomic clock timed). This was aided by finding it in binoculars at about 7:34 so I knew exactly where to look and then ... after a few more minutes of sun setting ... there it was, very faint. :P

Given my aging eyes, I would certainly hope some of the younger members could break my new record. Scan with binoculars from S to SW up to about 30 degrees starting about 7pm or so, and when you find Sirius, note the location relative to buildings or trees and the time. Then stare until you see the star.

Who can beat 7:37:15??? :lol:
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Mark G
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Unread post by Mark G »

Well Bob I can't beat your eagle eyes & early spotting of the Dog Star. But, Bob M, Joe B & I did have a scope on Sirius at 9 pm tonight. While it was low and sinking fast we could see a distinct lump on the eastern side of Sirius. I'd say a pickering rating of 3-4 is what we had to view through tonight. Now with the wildly scintillating atmospherics & (tube currents?) we would swear we almost saw the pup tonight. But, seeing the pud requires better seeing conditions that what we had tonight. I hear last night was the night to see it. :( Tonight, even at 1000x power that eastern "lump" was visible. But 465x gave the best view and the lump was still there. So no confirmed sighting of the pup tonight...

FWIW I do know that someone in our club did spot the pup in a 4" refractor last night. I'm sure a posting will be coming before too long. 8)
Clear skies,

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Rotorhead
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Unread post by Rotorhead »

Well, 'seeing' the Pup is somewhat conjectural... What I did was cheat. I had heard that the Pup would cause a defect in a good set of diffraction rings in the form of a very faint set of its own diffraction rings on the side of Sirius corresponding to the Pup's location. Using about 300x, I got a lovely set of diffraction rings around Sirius, and there was a 'bubble' within the first two rings that was not an artifact. I moved my observing position and rotated the ep to ensure that I was not picking up a reflection in my eye or a bit of dust on the ep. The effect was rather like looking at the Bubble Nebula with a good filter, imbedded within the two outer diffraction rings of Sirius.

Last night at UMD, we could see a distinct blue/white area of glare on the side of Sirius (east side) corresponding to the Pup's current location. The color shift typical of Sirius at high power (blue, yellow, green and red) was visible on all quadrants of Sirius except for this one spot, which never changed from blue/white. Could this have been the Pup attenuating the color? Maybe. Using lots of averted vision (and even more 'imag-i-vision') I was occasionally seeing a tiny dot which I believe was the Pup, but the others could not confirm it, so perhaps I was merely seeing what I wanted to see.

This is a good challenge. I think one will need to observe earlier - putting Sirius higher in the sky, as soon as Sirius is visible - or else use an occulting ep to see this little guy. As Brian, Rebecca, and I learned last year, there are at least two faint field stars near Sirius that can cause 'false positives' when searching for the Pup. Know your position angle: the Pup is almost due east of Sirius right now, (dob drivers beware: the Pup may be hiding under a diffraction spike!!!) but those field stars are due south and northeast, I believe, but well outside Sirius' glare field. Basic rule of thumb - if you see the Pup as soon as you see Sirius, you aren't looking at the Pup... :?

I am NOT claiming the Pup yet. But the chase is fun.
Bob M
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Galactus
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Unread post by Galactus »

Sounds like a nifty chase. As I am up at 5:00 AM and at my desk at work at 7:00 AM after riding a bus to Providence and often still at my desk til 6:00 PM...sorry to sound lazy like some dome boys I know, but this seems like too much work at this late in the season...sigh :roll: :)
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BobSikes
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Pup Chasing - Daytime

Unread post by BobSikes »

Nice job working on the pup. I wonder if you would have any luck spotting Sirius with the UMD scope at the beginning of twilight. It's not so bright like Venus you can spot it in the full daytime, but if you could locate it at 6pm or so it's a lot higher. Maybe a better chance for the pup then. 31 deg at 6pm vs. 15 deg at 9pm. And sometimes a little backlight can help equalize the magnitude differences -- maybe.

BobS
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Pete
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Unread post by Pete »

I tried for the Pup a year ago when Sirius was well positioned and came away with zip. It's moved out another arc-second now, and next year it'll be a bit better still. I ignored the Pup this year as any view would still be in question. Next year we can get the little bugger.

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Paul D
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Unread post by Paul D »

Bob,

I would also argue that if your saw the pup using diffraction as you say, that you DID see the pup. You used your eyes to observe what you did. If we rule out your way of doing it then we could rule out any use of filters etc. because they aid us in seeing better.

Now if there was only a way to measure the blip you have. I believe that the pup is only a few arcseconds away from Sirius. If we could figure out how that translates into your blip on the diffraction we could confirm what you saw.

I had always thought about using a filter to find the pup but the filter that kills the glare would kill the pup as well. How about making an occulting ep with filter like material to kill the glare of Sirius but not the pup? Any ideas? Rubylith like what I use to kill the glare on my computer screen when I observe? An occulting rubylith EP? This may be the ticket?
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Pete
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Unread post by Pete »

Paul D wrote:How about making an occulting ep with filter like material to kill the glare of Sirius but not the pup? Any ideas? Rubylith like what I use to kill the glare on my computer screen when I observe? An occulting rubylith EP? This may be the ticket?
That's exactly what I was using a year ago Paul, an occulting eyepiece using exposed film that allowed Sirius to show through at greatly reduced magnitude. Next year we should have sufficient separation.

Pete
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