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Old 02-11-2020, 10:06 AM
jahnpahwa (JP)
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Beta Phoenicis splitting

Howdy! Had a clear night last night, which means I'm pretty hept up in coffee now.
Had my 4" refractor out and going pretty nicely at 230x, split zeta aquarii without a sweat and then set out for something harder. Tried Beta Phoenicis, my southern skies book noted it was 1.4" but further reading suggests 1" or just under.
I wonder if anyone has split this? Can you let me know your set up?
I might've been dreaming but I thought that I saw perhaps some elongation but that'd be it and bit.

Oh, and if anyone is interested, the ep I used was a 5mm Hyperion with 28mm fine-tuning ring installed, which converts it to 3.2mm. I really think it's a great thing. Was as sharp as I could ask, and on the moon was superb.

Last edited by jahnpahwa; 02-11-2020 at 10:52 AM.
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Old 02-11-2020, 10:27 AM
glend (Glen)
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Hmm, I don't know about Beta P, Sky Safari has the separation listed as 0.7" (it's a binary star of roughly the same magnitude). I think it would be impossible with a 4" refractor. Perhaps "Wishful Seeing" was at work. Zeta Aquarii is more doable at 2.4", and I have certainly split that easily with my 127mm iStar f12. I will have a look at Beta P when I get the chance, but I believe it will not split with my 127mm, nor even show elongation.

Last edited by glend; 02-11-2020 at 10:38 AM.
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Old 02-11-2020, 10:48 AM
jahnpahwa (JP)
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Quote:
Originally Posted by glend View Post
Hmm, I don't know about Beta P, Sky Safari has the separation listed as 0.7" (it's a binary star of roughly the same magnitude). I think it would be impossible with a 4" refractor. Perhaps "Wishful Seeing" was at work. Zeta Aquarii is more doable at 2.4", and I have certainly split that easily with my 127mm iStar f12. I will have a look at Beta P when I get the chance, but I believe it will not split with my 127mm, nor even show elongation.
That'd be unreal, thanks Glen! And yes, I'd be very happy to concede that wishful seeing was at play. It took me a while to be sure that I was indeed looking at what should be a double!

I need to prepare a bit better for a session, get a list of doubles from 2.5 down to 1.7 or so, and work through them. At the moment I'm looking at books in the dark, trying not to shine a torch at my imaging scope, googling J2000 co-ordinates... its a mess!
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Old 02-11-2020, 02:12 PM
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Merlin66 (Ken)
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AstroPlanner has all that capability for you.
Worth checking out.
https://www.stelledoppie.it/index2.php
This is also a great source for all things double star.
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Old 02-11-2020, 02:43 PM
jahnpahwa (JP)
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Originally Posted by Merlin66 View Post
AstroPlanner has all that capability for you.
Worth checking out.
https://www.stelledoppie.it/index2.php
This is also a great source for all things double star.
Thats great Ken, thanks! So easy to find what I'm after! Will bookmark this for sure
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Old 02-11-2020, 11:53 PM
bigjoe (JOSEPH)
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JP TRY Pi Aquillae at 1.4" , Propus 1.4" , Pi Lupi an equal and 1.4"~ and Eta Orionis ~1.7", Mu Cygni (The yellow snowman) at 1.4" an equal pair,Beautiful Gamma Ceti at 1.99"; all great doubles.

They're easy enough in my 115 triplet..should be great in your 4" ..I bagged Propus in a 90 achro once...and while your at it look at Theta Indi a wide 7" but beautiful creme white Primary and a lovely claret Wine secondary!
Bigjoe.

Last edited by bigjoe; 03-11-2020 at 12:05 AM. Reason: Adding
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Old 03-11-2020, 04:38 PM
Saturnine (Jeff)
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Hi JP

Out of curiosity and because I like double star observing, I had a look at Beta Ph last night or I should say early this morning. Using an 10" f6 newt on an EQ6 at 300X I would have to say splitting A / B was inconclusive. The seeing was average, maybe 5 / 10 Pickering but in moments of steadiness it seemed that there were 2 Airy discs, touching, forming the classic hourglass shape.
The quoted latest measures in the WDS are 0.6" separation so in reality to get a definite split an aperture of 12" or more would be needed, along with good seeing conditions.
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Old 03-11-2020, 08:31 PM
jahnpahwa (JP)
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ah, this is so excellent!! Thanks heaps for checking it out and posting your findings I have a 12" dob, but i might need a few years of pilot training to be able to locate any positive numbered mag target



And Joe, thanks heaps for the list! I'll definitely have a go at them soon. Thats exactly the ballpark I'd like to play in.


I'd really love to read more about people's visual sessions, so if anyone is shy about posting because they reckon people wouldnt be interested, please dont hold back!!


You guys are great, cheers!
JP
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Old 03-11-2020, 09:59 PM
glend (Glen)
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Quote:
Originally Posted by Saturnine View Post
Hi JP

Out of curiosity and because I like double star observing, I had a look at Beta Ph last night or I should say early this morning. Using an 10" f6 newt on an EQ6 at 300X I would have to say splitting A / B was inconclusive. The seeing was average, maybe 5 / 10 Pickering but in moments of steadiness it seemed that there were 2 Airy discs, touching, forming the classic hourglass shape.
The quoted latest measures in the WDS are 0.6" separation so in reality to get a definite split an aperture of 12" or more would be needed, along with good seeing conditions.
Jeff, I put my 8" GSO f12 Cassegrain to work on Beta Ph tonight. The Seeing was pretty good here but i think I was right at the Dawes limit for my scope with that separation. The diffraction spikes did not help and the two stars are near identical magnitude. I thought I could detect elongation at 200X but would need another observer to verify that.

I did not try the 127mm iStar refractor..
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Old 04-11-2020, 02:42 PM
bigjoe (JOSEPH)
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"And Joe, thanks heaps for the list! I'll definitely have a go at them soon. Thats exactly the ballpark I'd like to play in."


No probs thats just some off the top of my head from memory many many more
Epsilon Arietis mags 4.6,5.2 ..sep 1.3" Yell/blue
SAO 075673, is another neglected gem..I could go on..always bag a few whilst watching a Ganymede/Io transit etc..
Cheers Bigjoe.
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Old 04-11-2020, 02:58 PM
Saturnine (Jeff)
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I tried to post a little earlier but the site was offline or something.

JA.
There is a list of 110 Southern Doubles in the Projects and Articles section, of all manner of separations and magnitudes for you to have a look at over the year, if so disposed.

Glen
Was interested in your observations with the 8" GSO CC. The 0.6 " separation would suggest that the scope would be struggling to split them but maybe an elongated Airy disc is possible. I remember a few years ago trying to separate Gamma Circinus, h4757, mag 5.0, 5.7 , sep 0.8" with my then 8" newt / dob and just being able to detect an elongated Airy disc .
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Old 07-11-2020, 07:47 PM
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The Mekon (John Briggs)
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I have been trying to split Beta Phoenix for almost 30 years. Commencing when I took delivery of an Astro-Physics 130EDT in 1991. I was using Burnhams as a guide back then and it lists this star as 4-4 @ 1.4". At the time, I could not understand why I could not split this star as I was doing so on other stars down to 0.9". Of course the true separation was perhaps less than 0.5" so not surprising. My last observation I have logged is from 25th Dec 2018 where I noted that I could make out elongation in my 18" at 430x. And that is what I reckon you will need. It is getting wider, so I may split this star one day!

Last edited by The Mekon; 08-11-2020 at 06:47 AM.
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