Celestron 9.25 Evolution Telescope

[Bigzmey]

I wondered where did you go. I am also waiting for the dry summer weather but it gonna be awhile. There are still May gray and June gloom ahead.

[Flyhigh7]

I had a clear night 2 nights ago (so I thought) but with accurate alignment and M81 and M82 fairly high in the north sky I could not find these galaxies or maybe the better word is could not SEE these galaxies. I'm afraid my sky above my house is too polluted with light and airplane exhaust to see objects of a surface brightness dimmer than 10 though I find this hard to believe with a 9.25 inch aperture telescope.

Tonight maybe be a clear night and my plans are to try to find the galaxies M65 and M66 below Leo when it gets high in my SE sky. Their surface brightness is around 12.36 so I'm guessing I won't be able to see them.

I have found some very pretty open Clusters in areas where I see no stars with my bare eyes so this telescope is doing something.

[Bigzmey]

Galaxies, even brighter ones, could be tricky under light polluted skies. But as your signature says 'The only way to make it is to try!'

Large aperture scopes produce small field of views, so even slight inaccuracy in GoTo may place the target out of the EPs FOV. This is why it is critical to confirm that you are at the right location comparing the star pattern you see at the EP to the FOV generated by SkySafari.

Once you confirm the right location work slowly through your EPs starting from the lowest power (36mm). At each power sit on the view for a minute, employ averted vision tricks to see if you can spot some faint glow.

Your 36mm EP without reducer will produce about one degree TFV (as shown below). If your sky is bad only the galaxy cores will be visible in M81 and M82 and they could be pretty faint.

[Flyhigh7]

Well, as I expected I could not SEE any of the galaxies around LEO but I was able to SEE the Ghost of Jupiter proving my alignment was good. I'm afraid my sky has way too much light pollution. It doesn't get black. It's always grey and almost the same shade of grey as the background color in the area I am typing this reply. So it's a pretty bright sky. This telescope is can see faint objects in that anywhere I point this thing I can see stars of varying brightness which is why I just don't understand why when I'm pointed right at a galaxy I don't even see a smudge of nebulous haze. I just see my grey sky. I can move the scope slowly around the area without losing alignment and so I do this in case the alignment is off but averted seeing and regular seeing doesn't show anything in the area of these galaxies.

The Ghost of Jupiter, NGC 3242, was cool and the first planetary Nebula I have ever seen.

It has to be my sky that prevents me from seeing anything when pointed at a Galaxy. And that is taking my time trying all my EPs with the Baader Silver BBHS 2" Diagonal.

My alignments seem to be more accurate with the Celestron GPS and I'm guessing that is due to a more accurate time of day that it provides that has to be better than the clocks in my house.

I will add that when I saw Andromeda from my home in Florida in a 6 inch Reflector clear as day my sky there was black. Not grey like it is at my home in TX. Oh, and I couldn't even see Polaris tonight. I rarely see this star.

Any thoughts from you guys would be greatly appreciated.

[Flyhigh7]

I bought a Unidren Sky Quality Meter and after several reading in my yard I know for sure why I'm having a hard time seeing faint objects. I'm getting average readings of 17.3 Mag/acrsec(squared). They give you a chart that goes from 17 (bad light pollution) to 23 (very little light pollution) so I guess my sky is about as bad as it could be. Bummer!

[Bigzmey]

That's strong LP, indeed. At least you got a good-sized scope and GoTo.

[Lady Fraktor]

Maybe there are some darker areas within a short distance of you.
https://www.cleardarksky.com/maps/lp/la ... n_map.html

[Flyhigh7]

Well after a long wait for a cloudless evening, I went out last night to observe the following list of Globular Clusters and their Surface Brightness:
M68 12.24
M53 13.01
M 3 12.31
M 5 12.25
M13 11.04 Great Hercules Cluster
M92 11.92

After aligning the telescope each one of these appeared almost dead center in my EP after dialing them up on the GoTo software. I am extremely pleased with how perfectly this telescope can 'goto' whatever I tell it to after I align it. I have found it is more accurate to align the telescope using higher magnification EPs.

Most of these globular Clusters were between 40 to 60 degrees above the horizon during my observations and it was a clear sky though the light pollution at my house is so horrible my Sky Quality Meter reading was 17.09.

All 6 of these magnificent Globular Clusters appeared as a grey cloud or nebula in the typical Globular Cluster shape where the nebula appeared more dense toward the center. Using all the EPs I have to observe each at low, medium, then high magnifications I was unable to resolve any stars. This was very disappointing to me as I have resolved the stars of Globulars with a 6" Reflector back in 1985-1986.

I'm afraid my location is too light polluted for me to enjoy the deep space objects I want to observe even with this big 9.25" Celestron Telescope. It would be hard for me to travel to a better location as I have 2 little budgies to care for and I'm not sure I can fit all my observing equipment into a little corvette. Also this car has a racing suspension and it would be hard on the Telescope if I hit any bumps. I have no case for it and what I believe to be the closest darkest areas near me are at least a day's drive away.

Maybe in a month when this list of Globulars will be higher in the sky to me I may be able to resolve some stars. This is my hope as I am now convinced my light pollution problem is serious. I mean how the heck can a 9.25" telescope with top of the line optics not resolve M13 with a surface brightness as low as 11.04? Please tell me it's because it was only half way up from my horizon and I may resolve it once it gets as high as my zenith but I have very little hope for this.

Thanks for all your comments guys and gals!

[Bigzmey]

I can relate Nick! I wish I could have the dark sky of my youth, but we have to get by with what we have now. From this point I see you report as half-full, rather than half-empty. You did observe quite few globulars with some details, and this is a win IMO!

Still, there are some tricks yet.

One, as you say to observe DSOs at their highest in the sky.

Second, try observing early morning. There are a few factors contributing to that, but on average I get better views observing pre-dawn.

Third, try the Baader Moon and Sky glow filter you have. The effect is mild, but it does provide views with a bit more contrast under the light polluted skies.

Finally, just keep at that. Viewing conditions can change greatly from night to night and when the seeing and transparency a bit better you might be able to resolve some stars in globs.

[Flyhigh7]

Thanks for the reminder. I should have tried that Baader filter. I'll try the same list again and by time I get another clear night they should be a little higher in the sky.

One Question:
Would these images be bright enough to resolve some stars if I use the f6.3 Reducer?? That is another thing I forgot to try. I know the lower Focal Ratio can yield a brighter image but I'm achieving it by adding a few corrective lens in the light path so I wonder if it will make a difference for live viewing.

[Bigzmey]

One Question:
Would these images be bright enough to resolve some stars if I use the f6.3 Reducer?? That is another thing I forgot to try. I know the lower Focal Ratio can yield a brighter image but I'm achieving it by adding a few corrective lens in the light path so I wonder if it will make a difference for live viewing.

Not at the same power. Let's say you are aiming for 120x. Without reducer it will take ~20mm EP in your scope to get that, with reducer you will need ~13mm EP. The brightness will be the same.

Using reducer with some EPs may result in vignetting and some light loss. Also, slower focal ratio produces a bit more stable views when seeing is poor. So, typically under the same power native F10 produces better views then reduced system, at least to my eye. This is why I have stopped using the reducer.

The main advantage of the reducer for visual is to get wider views with your low power 36mm EP.

[Bigzmey]

Some afterthoughts

As I indicated, at the same power there should be know difference in the scope performance with or without reducer. However, since the reducer has an odd x0.63 factor you will end up with two different sets of magnifications using your EPs with and without reducer. So, just because of that you should try it.