A night with the TEC140.

[ollypenrice]

Wot no camera in the TEC? That's right, I had some 'visual' guests so we took a stroll with the big apo. Was it ever a good nght out.

Seeing was disappointing on the planets but the sky was ultra transparent so we did deep sky.

M42 at 38x in a 26 Nagler; Both the bright arcs either side of the Trapezium swept out, faded, then just - I mean just - reeappeared and connected on the opposite side so you see the whole M42 structure. This is quite rare to see and immensely satisfying. The TEC is a dream of a scope optically so the stars were tiny. The bird's head shape of M43, De Mairan's nebula, was visible but showed better at higher power. Nebulosity was clearly visible for the Running Man but the man shape was impossible to discern. Again at higher power the mottled nebulosity around the Trapezium was clear and detailed and the Fish Mouth also showed more than just darkness.

Rosette at 38x; unfiltered you see immediately that there is nebulosity around NGC2244, the central cluster. it is subtle but you see a slight milkiness in the sky and a suspicious drop in the star count, so you know it's there. Put in an O111 filter and it is unmistakable. There's very easy nebulosity in the shape of an angular capital C bracketing one side of the cluster and on the opposite side there's O111 nebulsity just touching it. This is not the full nebula as seen in Ha images. I know from imaging it that the O111 signal lies within the boundary of the Ha and it looked very much as it does using a CCD O111. Small, clumpy patches. This was very exciting to behold.

M45, Gorgeous. Just a hint of nebulosity tonight. I've seen more on occasion but the object was well past its best in the sky. The Double Cluster. Stuck for words! M35 and little NGC2158 were stunning, the sheer brightness of M35 making it leap out of the sky.

We then took in M82 and 81. Even in the widefield view the dust lane cutting the Cigar was easy and the disc of M81 was extended. It really was a cracking night and now that the village lights to our north go off at 11.00 there is a small improvement in the Northern sky.

M51 was very low, the Crab showed up cleanly... all good stuff.

When perfect transparency is maximising the light grasp, as on this night, I just wouldn't swap the TEC for anything. My refractor-itis is never going to change!! It seems that the TEC140 on ABS has now gone so someone is going to be a happy bunny.

Olly

[Double Kick Drum]

Great report.

It sounds like a mighty fine scope / sky combo to get easy views of the M82 dustlane and the other detail you describe.

I've got to get to some dark skies soon!.

[MjrTom]

Great report Olly

I am seriously going to have to convince the wife a trip to the south of France is much needed.

What I would give to look though a 140mm APO Triplet (and the 20" Dob for that matter!)

[Graham Darke]

Nice one Olly,

As you know I need no convincing about the TEC140! A few weeks ago the Running Man Nebula was visible in mine from light polluted Tyne & Wear! No filter used (or even required). That you have one at that Southerly latitude in a dark site, well I'm very jealous!

Graham

[ollypenrice]

That's impressive, Graham. I wonder what you think about the question as to what kind of instrument performs best in LP. I really don't know. I've heard it said that a long focal length refractor does best but that's just hearsay for me.

Olly

[Nexus 6]

what kind of instrument performs best in LP.

interesting question...should we not know what does? it would be something many people would consider buying in helping them get some sort of enjoyment from light polluted locations I would think.

[MjrTom]

I think it comes down to contrast.

The refractor is able to see subtle detail easier where as an optical system which lacks this contrast is lost in the skyglow.

[ollypenrice]

Not an easy 'back to back' to perform, though.

Olly

[Merlin66]

When I want a "night off" I go back to my trusty ol' Genesis.....it's fun to just enjoy what the night sky has to offer.

[Graham Darke]

Best scope for light polluted skies eh?A few schools of thought on that one; First one says go for a scope that performs best on objects least affected by LP, so planets, double stars etc. - here the refractor or maksutov wins; second go for a large aperture coupled with a light pollution filter. I've always found longer f ratio instruments performed better under light polluted skies f7 at least. Anything faster suffered. Sorry to bang on and on about the TEC but it performs better than anything else I've owned under any skies, light polluted or not. I'm sure contrast plays a big part.