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Challenging double near Jup

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#26 aa6ww

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Posted 06 January 2013 - 11:10 PM

Last night I noticed that a 6th mag star posing as a 5th Jovian moon is actually a challenging red double star. According to Skysafari Pro it a 5.9 and 8.5 mag double with a sep of 2.0 arcseconds. It took the 16 LB to split it last night in okay seeing. The 8 and 12 inchers were not doing it by the time I realized it was a double on the phone Jupiter was above my house and seeing was down but the Lightbridge was in the front yard and seeing was better there. The star is HR 1370.


This double was brought to my attention tonight so I thought Id give it a shot since it finally stopped raining and appears to be clear now.
At 400x, its in and out at best, definately more out than in. The seeing is suppose to improve in an hr or so based on the CSC so well see how that works out. right now the seeing is just 2/5 and the primary red star is blurring in and out and just periodically settles down. I ran out of eyepieces on my TOA-130, I was using my 2.5 Nagler which got me to 400x. I needed this much magnification to pull the secondary star far enough away from the main stars blur. I went with the 3.5 Nagler and barlow, (570x) and the split was easier to see. It's still pulsing in and out because of the seeing, but I can see the tiny light blue secondary star beside the larger red one in a 3:OClock position from the main star, at least based on how my diagonal is positioned in my scope where the eyepiece is pointing north. The configuration is exactly as the photo I posted shows. Even at my 14mm initial eyepiece at 70x, the red primary star is definitely obvious. A rock solid polar alignment and micro focusing are both crucial to get this all to work.

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#27 Darren Drake

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Posted 07 January 2013 - 12:52 AM

Tonight some friends and I split it with 3 8 inch scopes but the 16 lightbridge really split it well and revealed that the fainter companion is quite blue. So this is like the ultra challenging version of Alberio....

#28 aa6ww

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Posted 07 January 2013 - 03:12 AM

The seeing conditions really cleaned up and all the blurring and pulsing viewed became very crisp after all for me. I just couldn't get what I could consider a satisfactory split with my 3.5 Nag in my TOA-130, and but the 2.5 Nagler at 400x was excellent and was even showing some out of focus detraction rings.It was still a very small split for a 5" scope, but very clean with jet black skies after all. The transit of Jupiter was also excellent and very sharp showing much more details than the seeing conditions were suppose to give me. It felt more like 4/5 for seeing than 3/5. Pretty fun for a quick few hrs on the patio!!

...Ralph

#29 desertrefugee

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Posted 07 January 2013 - 09:12 AM

Pretty much what I saw (as described above) with an ES ED127 and Nagler
3-6 zoom.

#30 ATM57

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Posted 07 January 2013 - 02:37 PM

Clean split the star at 170x with my Celestron C6R. Nice view. Went to 240x to comfirm. The secondary is "delicate" and can dissappear under less than steady seeing. The attached image is a simulated (cropped) view at high power (300x).

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#31 azure1961p

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Posted 07 January 2013 - 07:19 PM

ATM, very nice sim image. Thanks for the description!!!

Pete

#32 azure1961p

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Posted 07 January 2013 - 11:11 PM

Ed I agree 240x EXACTLY was the sweet spot. Nice rich rusty red orange star. My aperture showed the companion merely as grey. Not saying the blue others have seen was false but I couldn't budge a true color from it.
It was a terrific view - nice intermittent diffraction rings sharpening with clarity now and again. I tried high mag of 450x and. Like your experience it was too mushy. The 240x was much cleaner.

Satisfying to find that so close to an already great object!

Prte

#33 azure1961p

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Posted 07 January 2013 - 11:12 PM

Post deleted by RLTYS

#34 Patricko

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Posted 08 January 2013 - 02:18 AM

Got this double system tonight just before the clouds moved it. Seeing was 4/5 and Ganymede was resolved as a disk @400x with my C6 SCT. Primary appears orange, secondary garyish/blue, P.A. matches what I saw visually. A very easy find with Jupiter nearby. Had the clouds not been a factor with the steady seeing this double would be down right easy.

#35 larry7

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Posted 08 January 2013 - 11:06 AM

After reading all the posts concerning this double I decided to check it out last night. Using a Jaegers 6" F/8 OG at 175x and 245x split easily. Then used aperture stops to see what would be the minimun aperture for a clean split. At 100mm both 175x and 245x still nice split. At 89mm 175x was a no but 245x still there, not easy but the secondary clearly seen. At 76mm no split at 175x, 245x or 305x. Cool stuff.

#36 Darren Drake

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Posted 08 January 2013 - 11:37 AM

Thanks Larry that is exactly what I was looking for.

#37 Darren Drake

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Posted 08 January 2013 - 12:20 PM

Acording to SkySafari Pro the spectral classes of the 2 stars is M0 for the brighter component and B3 for the dimmer one. This actually represents a higher color contrast than Alberio. So I wonder what aperture is needed to see this color contrast? Most smaller scopes than 8 inches or so aren't revealing this blue color but it sure was obvious in the 16 inch. Looks like this is the very challenging version of Alberio...

#38 Cepheus Elf

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Posted 08 January 2013 - 06:33 PM

Failed to split this tonight with my 127 Mak but the seeing was about 6/10 and deteriorating. Nice rich orange star though...I bet it looks great when split!

Mick

#39 fred1871

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Posted 08 January 2013 - 06:49 PM

Interesting - Larry's notes indicate a new benchmark for this double - seen with only 89mm aperture (3.5-inches) at 245x; and at 175x with 100mm.

This suggests very good air steadiness and high visual acuity by Larry. Maybe the "small aperture" syndrome as well? Larry, feel free to add further information. :)

Darren - yes, it appears that 8-inch helps for seeing the companion as "blue" - at mag 8.6 that's not too surprising, though Ed D saw the colour in the secondary with his 6-inch Newtonian. I expect individual observers have different threshold points on star brightness, where colour is perceived vs the star looking grey ("ashy" was a term often used in the 19th century). It's the well-known phenomenon of "all cats are grey in the dark".

#40 Asbytec

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Posted 08 January 2013 - 09:13 PM

Yea, I did not notice the companion offering any color in a 6".






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