Some Orion doubles under the moonlight

[RobertI]

My plan was to do some Luna with my new binoviewers on the102ED-R, but I discovered a serious problem with them (hopefully FLO will swap them) so diverted to some doubles in Cyclops mode instead. I added the 10x60 RACI finder to make star hopping easier under the bright skies and I have to say I REALLY like this configuration, it was very easy to track down even faint target doubles,  and easy to view through both finder and main scope while seated in comfort. Seeing was good and the stars looked slightly surreal with their classic diffraction rings and well defined airy discs. Dew was ever present and the dew heaters on the main objective and eyepiece did a sterling job. I used a 8-24mm zoom with a 2.25x barlow.

Tonight's haul included the following:

• Alnitak - Mags 1.17 & 3.7 separated by 2.2", often challenging with the glare of the primary but easily split tonight.
• Eta Orionis - Mags 3.4 & 4.9 with a separation of 1.8" - the secondary was easily visible at 200x lying in the first diffraction ring.
• Theta Orionis (Trapezium) - Tonight the E component was visible but the F component eluded me - darker skies possibly required.
• Rigel's tiny companion was nicely visible even at lowest magnificiations.
• Zeta Orionis - A beautiful multiple comprising four visible components, with another multiple nearby. Interestingly the faintest component (the 9th mag 'C' component, just to the left of the brightest star in the poor quality sketch below) was initially invisible until I backed off the magnification and it suddenly popped into view.

I also tried some fainter doubles in Gemini but the bright skies proved too challenging to split them. But it was nice to be out again after several weeks of cloud.

 

[Nik271]

Sounds like a very good session! Here it was clear until about 7pm and then the clouds came. I only got a look at the Moon but the seeing was very good indeed.

Interestingly I  also see the dimmest star C in Sigma Orionis only in certain lower magnifications with my 5 inch Mak. It must be because of the need for the right exit pupil for the sky brightness. 

[RobertI]

1 hour ago, Nik271 said:

It must be because of the need for the right exit pupil for the sky brightness. 

I think you’re right - I would have made a note of the zoom setting for reference but it was covered by the eyepiece dew-band!

[Paz]

Nice report, I was out binoviewing the moon with my ed102r. I've finally got binoviewing working for me after a couple of years of working at it, initially having faults in them and latterly sorting out my technique.

There was thin cloud and a big ice-ring around the moon a lot of the time.

Doubles in Orion was also in my plan but I only fitted an rdf and star hopping was going to be too tough without a raci finder so I only did Alnitak.

Edited December 28, 2020 by Paz

[chiltonstar]

There are some superb doubles and multiples in Orion. To spot fainter stars like C Sigma Orionis, I find a cheapo zoom (7.2 - 21.5 mm Hyperflex) invaluable. When I've found a good magnification for the seeing conditions, I change the eyepiece for a better quality fixed focal length one, although it has to be said, the Hyperflex performs very well with a long focus mak.

Chris

[RobertI]

1 hour ago, Paz said:

Nice report, I was out binoviewing the meeting with my ed102r.

Must have looked spectacular. What sort of magnification do you achieve with your BV setup? 

[RobertI]

1 hour ago, chiltonstar said:

To spot fainter stars like C Sigma Orionis, I find a cheapo zoom (7.2 - 21.5 mm Hyperflex) invaluable.

Agreed about the zoom. You wouldn’t think that a cheap zoom with an achromatic barlow would be that good for doubles, but it seems fine. I was tempted to swap for a better quality eyepiece but everything seemed to be working (including the dew heaters) and the clouds were threatening, so I just left as was!

Edited December 28, 2020 by RobertI

[Paz]

45 minutes ago, RobertI said:

Must have looked spectacular. What sort of magnification do you achieve with your BV setup? 

In theory 83x and 186x. I started off with a 2.6x gpc and 20mm SLVs for lower mag as I was observing through thin cloud. Then it cleared up later so I went up to 10mm SLVs.

The gpc was close to the binoviewer so the magnification factor was I assume roughly as advertised. If I put more distance between the gpc and the binoviewer the magnification factor goes up but I've not measured the effect.

By the way where I say "meeting" I mean "moon"!

[RobertI]

27 minutes ago, Paz said:

In theory 83x and 186x. I started off with a 2.6x gpc and 20mm SLVs for lower mag as I was observing through thin cloud. Then it cleared up later so I went up to 10mm SLVs.

The gpc was close to the binoviewer so the magnification factor was I assume roughly as advertised. If I put more distance between the gpc and the binoviewer the magnification factor goes up but I've not measured the effect.

By the way where I say "meeting" I mean "moon"!

Ah, I thought you meant the 'meeting' of Jupiter and Saturn! I was unable to quite reach focus with my BVs using the supplied 1.6x GPC and 20mm e/p's, so opted for using my 2.25x Baader barlow, which actually gives a magnification factor of 5x with the BV - the resulting magnification of around 175x was perfect for Mars. But I'd like to experiment and I may get the 2x GPC for lower powers.

[John]

2 hours ago, RobertI said:

Agreed about the zoom. You wouldn’t think that a cheap zoom with an achromatic barlow would be that good for doubles, but it seems fine.....

It's a good combination for planets as well:

 

[RobertI]

1 hour ago, John said:

It's a good combination for planets as well:

 

Thanks for the link John, actually it was your recommendation that led me to getting the Baader barlow to complement my zoom (although I had hadn’t seen the above post) - it’s turned out to be a very multi-talented little tool - thanks again! 

[RobertI]

On 28/12/2020 at 00:34, RobertI said:

My plan was to do some Luna with my new binoviewers on the102ED-R, but I discovered a serious problem with them

An update on the binoviewer problem - it looks like the issue is caused by my use of the 2.25x barlow with the BVs, as when I tried the 1.6x GPC with the BVs the problem disappeared. So looks like I will need to find another route to getting high mags with the BVs in my 102ED.