The Official Astronomy Thread

[Crusader]

Hey Crusader

Thanks for all the help a few months ago wrt. all my questions when I was looking to buy my 1st telescope.
i bought everything u suggested, and have recently had a look through MUCH more expensive eyepieces etc etc.
And i must say your recomendations were spot on re the skywatcher 8-24mm. I saved myself R1500 on that alone.

Found my 1st galaxy the other night (smc & lmc dont count), nothing much compares to the feeling, its like finding a diamond in the sand.

No problem. There really is a nice sense of achievement when you find your first fain fuzzy. Nothing else quite compares to it.

Did you end up buying the 8" Skywathcher or did you manage to get an adaptor to fit your existing scope?

 

[SYN]

I bought a 8" Orion, It was cheaper new than the guy wanted for his 2nd hand Skywatcher (only R3980.00). Also bought the 8-24mm eyepiece, A 2,5 times APO shorty barlow (giving me up to 375X magnification) and a neutral density filter, for the moon apparently. o... and a green laser pointer
Scope is cooling atm. Nice weather here in Cpt for the 1st night in a while, gonna see what there is to see tonight. Its amazing how the sky fast the sky changes in just a month or two. I need to print a few maps again and start looking for new things

 

[Crusader]

I bought a 8" Orion, It was cheaper new than the guy wanted for his 2nd hand Skywatcher (only R3980.00). Also bought the 8-24mm eyepiece, A 2,5 times APO shorty barlow (giving me up to 375X magnification) and a neutral density filter, for the moon apparently. o... and a green laser pointer
Scope is cooling atm. Nice weather here in Cpt for the 1st night in a while, gonna see what there is to see tonight. Its amazing how the sky fast the sky changes in just a month or two. I need to print a few maps again and start looking for new things

Nice! I'm assuming it's the 8" XT Classic and not the Intelliscope series. I can highly recommend "Sky and Telescope's Pocket Sky Atlas" for star charts (remember to turn it upside down) and Stellarium software to show you what's up in the skies. Seeing is poor here, so I'm giving it a skip tonight. Will however try to get a peak at Jupiter early in the morning (if I can drag myself out of bed).

 

[SYN]

Last night was one of the best nights (atmospheric stability wise) ive had. Fog this morning kept me in bed. Yep it is a classic. Was always on a bit of a budget, and wanted to buy as big as possible. I am using Stellarium atm, and printing " star charts" from there. What finder scope are you using? I have been told to get a decent 9x50 finder, but i am slightly scared going back to inverted views again. The red dot works great for general positioning, but falls short when you need to starhop-search. I have also been told to stay away from right-angle corrected finders as these disorient you more than they help

 

[Crusader]

I have also been told to stay away from right-angle corrected finders as these disorient you more than they help

I use a 9x50 RACI finder. It works nicely in conjuction with a red-dot finder. Much more comfortable to use than a straight through finder and I don't find it disorientating at all. Guess it might be the case if you want view through the EP and finder at the same time. The non corrected versions are far more disorienting since the views are upside down so you have to reverse the movements of the scope, but these would mirror the view in the EP.

 

[SYN]

I use a 9x50 RACI finder. It works nicely in conjuction with a red-dot finder. .

Where did u get it from? How do you mount both the 9x50 and the red-dot on one mount? I was thinking of getting a nice wide angle 35mm EP to use as a "super finder", but i think the 9x50 will be cheaper

 

[Crusader]

Where did u get it from? How do you mount both the 9x50 and the red-dot on one mount? I was thinking of getting a nice wide angle 35mm EP to use as a "super finder", but i think the 9x50 will be cheaper

My XT10 came with a 9x50 RACI finder. That was before Orion 'economized' the Classic range by replacing the optical finders with a red dot finder and only including one eyepiece with the scope.

As for how you mount both. Easy! Double sided sticky tape. I taped the RDF on top of my optical finder. See pic here.

A large blob of "Wondergom" also works nicely. Used that method on my refractor and suprisingly it holds alignment very well and in more than a years usage haven't fallen off or gotten bumped once.

Technopro has a Skywatcher version that's similar to the one I have. It's not cheap though - R1110.

 

[SYN]

Please dont tell me it uses those 3 screws on the side to align, that is such a bad system.
Is this the same scope? http://eridanusoptics.com/store/index.php?main_page=product_info&cPath=20_31_32&products_id=256
I know some are not left/right corrected, only up/down

 

[Crusader]

That one looks like a straight-through and not a 90° one. Might mean more contortions to be able to view through it, but it should work. At least it's almost half the price.

And yes, it uses those 3 screws to align, but they are spring loaded so you really only adjust one. At least that's how my Orion one works.

 

[Crusader]

I really need to stop buying astronomy gear. Over in the US Meade has a jaw-dropping sale on their Series 5000 Super Wide Angle eyepieces (50% off the retail price). The pricing was too good to refuse so I've ordered a 24mm (1.25") and a 28mm and 34mm (2") eyepieces. I've never ordered from overseas before so this will be a learning experience. If I calculated the VAT and duty to the right ballpark figure the set of 3 eyepieces including the shipping will end up just R100-R200 more expensive than the single 24mm goes for over here. Even if the VAT is much higher I think it should still be quite a bargain.

 

[SYN]

I really need to stop buying astronomy gear.

You need a wife like mine. She will sort out that "problem" you seem to have

 

[Crusader]

Guess that's one of the reasons I'm more than happy with the single life!

 

[Meadon]

if we are able to see the moon's craters from earth with a telescope and lets say its nice and clear and everything, then i guess it would be possible to see some astronauts walking around there or the landing craft or would that be impossible. where would the astronauts land on the moon, would they land on the dark side or the side that we see.

Phil Plait has a nice explanation for why this isn't possible, here. By the way, the Lunar Reconnaissance Orbiter has now imaged the landers and foot trails of the astronauts, details here.

 

[SYN]

Hi Guys.. Ok i have a few astronomy related questions. hope some of you can help.
1. Is dew harmful ie. can it damage my primary mirror if I let it get dewed up and then close the scope up and take it inside for the night?
2. What can I do the prevent dew from cutting a nights observing short? (as it did last night)
3. Can one see the ISS through a 8 inch scope? The software that came with my telescope also plots the path of many man made satelites, and the ISS is passing over just below the southern cross tonight just after sunset. It is going to be reasonably bright - mag 3.4 so i am sure ill see it, but my question is will i be able to see structure detail (or people waving ) through my telescope?
4. There is a shadow transit by Io over Jupiter tomorrow morning from 05:30 to 06:30, and I wanted to know if a 8 inch scope will actually be able to see this shadow?

Thanks in advance for any help/advice.

 

[Crusader]

1. Is dew harmful ie. can it damage my primary mirror if I let it get dewed up and then close the scope up and take it inside for the night?

You have a Orion XT8, the smaller version to my XT10. Honestly, I can't say that I've ever had any problems with dew on my primary mirror, although that could just be because of my location. In principle Newtonian reflectors aren't that prone to dew, aside from dew on the secondary mirror on the front of the scope.

Dew can't really damage your mirrors (aside from creating streaks and water spots), but it wouldn't be a good idea to store the scope while there's dew on the scope. Allow it to dry off while indoors and then store it.

2. What can I do the prevent dew from cutting a nights observing short? (as it did last night)

You could try adding a dew shield. With refractors and CATs they help to prevent dew from forming on the corrector plate/front lens. If you have access to a power outlet and a hair-dryer you could give the scope an occasional blow (on coldest setting) to prevent dew from forming, or to evaporate dew that has already formed.

3. Can one see the ISS through a 8 inch scope? The software that came with my telescope also plots the path of many man made satelites, and the ISS is passing over just below the southern cross tonight just after sunset. It is going to be reasonably bright - mag 3.4 so i am sure ill see it, but my question is will i be able to see structure detail (or people waving ) through my telescope?

If you are lucky enough to catch it in view, then you should be able to detect some structure. Honestly you will have to set up your scope and have it pointed in the right direction in anticipation of the ISS moving through the FoV. I haven't even tried to manually track it. It will be moving extremely fast at any reasonable magnification. To give you an idea, someone imaged the ISS transiting in front of the Sun. The whole transit took 0.49s!

4. There is a shadow transit by Io over Jupiter tomorrow morning from 05:30 to 06:30, and I wanted to know if a 8 inch scope will actually be able to see this shadow?
That will depend on the seeing conditions and how well your scope is collimated. During some good seeing I managed to spot Io's shadow on a few occasions. The 8" should be able to do the same.

 

[SYN]

O well scope is all set up and ready to go. Let see what we can see!

 

[Crusader]

Sorry for the cold weather guys, but I just had to get another scope. This is definitely the worst new scope curse I've had so far.

I picked up a Skywatcher 6" Dob at a price I couldn't refuse. It arrived last night and needless to say it snowed on the surrounding mountains and the first clear skies are predicted sometime next week.

 

[SYN]

Crusader, Y buy a 6" dob if u already own a 10"? I have only had my scope for a few months and already want more resolution and brighter deep sky objects. So every time I carry it outside i catch myself thinking " hmm this is light, a 10" would have been manageable"

btw. how many scopes do u own now?

 

[Crusader]

This is my fourth scope. I always wanted a 6" as well to be able to see what small aperture has to offer, not to mention that I suffer from gear acquisition syndrome.

The 6" should be a nice grab and go scope as far as cooldown is concerned. While the 10" is cooling I will have something to occupy myself.

 

[Crusader]

Here's a pic of the Skywatcher 6" after being fully assembled. Luckily it was raining (and snowing) the day it arrived, so I had more than enough time to put it together at my leisure.

This is my first Skywatcher Dob, so it was interesting to see how it compared to the Orion version. Build quality seems very good, but the Orion had the edge with the addition of some "extras". The Orion has a navigation knob on the front of the OTA and some thumbscrews at the back which makes collimation easier.

The SW doesn't have the navigation knob (which I kinda miss since I'm used to it, although the new Orion versions also don't include it), it doesn't have any thumbscrews so you need a screwdriver and Alan wrench to do the primary adjustment (not a big deal really).

The SW implementation of a 2" focuser with 1.25" adapter is also a bit strange. With the Orion the 1.25" adapter is built into the focuser. If you want to use 2" eyepieces you just take out the adapter. The SW actually has two seperate adapters one for 2" and one for 1.25", so you will have to physically take each one out and swap between them as required.

I managed to squeeze a quick first light in when a hole appeared in the clouds. So far I'm pretty impressed with how this 'little' scope performs.