32 replies to this topic

[RAKing]

Zeta Cancri has always been one of my faves. But the tight A-B spacing has made it a challenge over the years and usually I could only guarantee a split if I used an 8 inch scope.

But the two have been widening slightly and I was able to get a nice clean split the other night with my 105 at 174x (3.5T6 Nagler). I then dropped in a Pentax XO 2.6 and saw a wide gap between the two.

IIRC, the A-B gap should be at or just above 1.1" (and gradually widening), so that puts it close to the Dawes Limit of my 105. At any rate, this means we should all be able to enjoy these gold beauties for many years to come!

Cheers,

Ron

[Cotts]

This pair rewards all those who go after it from 3" aperture and up. I use it as a seeing indicator in the spring. If the closer split is there then it's a double star night.......

Congrats on the split with 4".....

Dave

[astro4565]

I'm glad you split that one cause I want to try it in my Williams Optics 120mm refractor. I need a good challenge this spring and would like to split that one and I would like to split Isar in Bootes. Weather looks better tomorrow so maybe if I get some power on it, that will do the trick. I think the Dawes Limit on my scope is .90". Maybe by next year it will be easier.

[Bonco]

Isar shouldn't be problem if conditions are reasonable. Very doable in a 60mm.
Good luck, Bill

[joaoba]

Nice work! My log says it's a triple but I've never split the A-B. I'll have to spend more time with it this spring with my C102GT.

[RAKing]

You might be able to split it with your 102, especially out in Montana. If so, you will see three almost equal golden yellow beauties, at 5.6, 6.0, and 6.2 mag. They are beautiful!

Zeta Cancri was at 1" in 2008 and will be widening until 2020.

Like Dave, I use Zeta Cancri to test my scopes and sky conditions every night it's up. I split it with the 6 inch Mak last week, but our humid Northern Virginia skies never let me split it with the 105 until now. That's why I'm so pumped!

Cheers,

Ron

[azure1961p]

Its one fine double. I enjoyed your account and conveyed enthusiasm. Its great when we get rewarded for persistence.

Pete

[WRAK]

More or less exactly one year ago a session in CnC with my 140mm refractor with full moon from behind and therefore rather bright sky and with moderate Pickering 5 seeing:
STF1196 (Zeta Cnc, HIP 40167) – 1.1/6.3“ multiple star +5.3/6.25/5.85mag. With magnification x40 C companion resolved at 1:30, limit aperture 30mm. With magnification x140 B companion resolved at 11:30, with x280 clean split, limit aperture 80mm.
I would assume that a smaller limit aperture is possible with better seeing conditions - but the 60mm Bonco mentioned may be a bit too optimistic.
This year I can only hope for a next clear night for another try - lousy weather currently.
Wilfried

[Bonco]

Wrak,
I commented on splitting Izar not Zeta Cancri with a 60mm.
Bill aka Bonco

[WRAK]

Bill, thanks - as this thread is on Zeta Cnc I overlooked your reference to Izar (yes, easy with 60mm).
Wilfried

[evan9162]

Split it pretty easily last night (and imaged it too).

Seeing was only mediocre. C6 SCT, Baader Maxbright binoviewers, 2x Televue 11mm Plossl, about 160x.

[joaoba]

We had our first clear night for weeks, but no luck w/ Zeta Cancri. I could see an elongation of the A-B pair but not a clean split. Transparency was good but seeing was average and everything turned to mush above 150x. I did see some detail on Mars and Izar was an easy split, but Zeta Cancri still eludes me.

[RAKing]

Hang in there and don't give up!

Ron

[astro4565]

I'd go higher in elevation if I were you. I split Antares back in 2011 at Rainbow Point in Bryce Canyon. Seeing was excellent at 9100 feet. I can't split it normally in the desert at around 2800 feet. Look for better seeing and keep trying.

[Mark9473]

I don't view doubles often but this thread inspired me to go and look for zeta Cancri. I found it a very interesting object with the very tight pair quite captivating. A very nice but tight split in my 107mm.

[schang]

You might be able to split it with your 102, especially out in Montana. If so, you will see three almost equal golden yellow beauties, at 5.6, 6.0, and 6.2 mag. They are beautiful!

Zeta Cancri was at 1" in 2008 and will be widening until 2020.

Like Dave, I use Zeta Cancri to test my scopes and sky conditions every night it's up. I split it with the 6 inch Mak last week, but our humid Northern Virginia skies never let me split it with the 105 until now. That's why I'm so pumped!

Cheers,

Ron

I tried last night with my C102. The seeing was not that good, 2-3/5. It was not a clean split, I could see the elongated AB pair, but no cigar yet with this 4" scope.

[karstenkoch]

I had better than usual seeing last night and was patrolling the stellar neighborhoods in part of the sky around Jupiter, Castor, and in between on the hunt for doubles. My SkySafari radar alerted me to a double called Tegmine. I steered my scope in that direction and found it easily. Nice bright double. I zoomed in with SS ... wait a sec! That's a triple! Okay, back at the eyepiece now ... can't see it. I dropped an LVW 3.5 in my SV102ED for 204x mag. The seeing was actually exceptional for where I live, but it just wasn't good enough to deliver a split in my scope assuming I could have managed it otherwise. But the elongation was clear to me. I'll be back. This one is now on my short list of most wanted.

[Cotts]

Splitting the closer pair with a 102mm scope is some good hunting!  I'll share my image from 2014 in very good seeing from the winter Star Party.   202mm aperture......

 

 

 

 

Dave

[Rich (RLTYS)]

Wow, nice image. 

 

Rich (RLTYS)

[PJ Anway]

Great image Dave!! 

[evan9162]

Here's mine from late April last year (seeing was below average)

C6 SCT + TV 2x barlow + T4i DSLR

 

[karstenkoch]

Is it just me or are C6's showing up all over cloudy nights in various posts? Based on this great image, I think I can see why!

[evan9162]

6" seems to be a Goldilocks size of scope where you start to get some decent resolution and light gathering, but are still flying under the radar a bit when it comes to punching through seeing.  It's easy to see why 6" refractors are considered seriously capable scopes.  The C6 gets you a lot of that capability in a much smaller package.

[Kon Dealer]

Did it last night with my 6SE

[Kon Dealer]

Did Zeta Cancri again with my 6SE. Also had my 90mm TS triplet out.
It gave crisper views of doubles like Algieba, Castor and Porrima, but couldn't get more than a "peanut"
out of the A-B pair.