The Official Astronomy Thread

4" is too small. I'd rather get a 6" or 8" Dob, but if you're going for a Mak, rather get something with more aperture, though it's gonna set you back a bit.
 
Lucky D: For terrestrial use you will be limited to a refractor, Mak or SCT. Unfortunately celestial and terrestrial isn't all that compatible. For celestial you need large aperture, the larger the better.

A 4" Mak is pretty small. You'll be able to see the planets, Moon and detect most DSO's although details won't be apparent. The Mak also has a narrow FoV so you will only see small pieces of the sky at once.
 
What is a DSO?
When you say I'll be lossing detail, does that mean that I'll be able to see the planets etc but they'll be blurry and fadded? For example would I be able to see Saturn and it's rings or would it be just a blurry blob

Thanks for all the input
 
DSO - deep space object (galaxies, nebula etc...)
You'll be able to get less magnification on them, meaning you will see them further away with a smaller telescope.
 
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You will be able to see the planets just fine although the magnification you can use would be around 200x for the Mak. Seeing will play a huge role as to how crisp the images are. If the atmosphere is unstable then it will be blurry in any scope.

DSO's will be very faint in 4". You'll be able to see something is there but you won't be able to make out much detail. As an example Omega Centauri will be a round patch in a 4" but in an 8" you will be able to resolve the stars easily.
 
As mentioned, you'll also be able to see Saturn and its rings, but it will be much "smaller". You also wont be able to, or will battle to do certain things that you can do with more aperture.

Say for example see the cassini division in the rings when its visible, or define the Great red spot on Jupiter. Also for example with things like the Trapizium in Orion, You would see 4 maybe 6 stars, where with more apeture, you would see that those 4 stars are actually much more.

Thing you need to ask yourself is do you actually want to be able to split faint double stars, or just look at the wonder of what is there in the sky. I personally wouldn't mind a 4" mak for quick observing, But then thats because I already have an 8" Newt for doing the things I mentioned above. You'll still be able to see MUCH more than you can right now with your eyes.
 
If you're just gonna have the scope in your house to view, then get a Dob. You won't have to issue of lugging it around, so you won't need a grab-and-go scope. 8" Dobs are quite cheap and popular.
 
Although it doesn't cover a 4" scope you might want to take a look at this scope comparison which should give you a rough idea about the difference aperture makes.

Another point is that it's not a good idea to view from inside a house (if I understood you correctly). Windows will distort the light and thermal differences will be a problem.
 
Crusader said:
Another point is that it's not a good idea to view from inside a house (if I understood you correctly). Windows will distort the light and thermal differences will be a problem.
Click to expand...

I was under the impression that he might stick the scope out the window? But even then, half the telescope will be heated from the house's heat and the other from the temperature outside. Probably not a good idea anyway as the scope needs to be cool for the best viewing experience.
 
The scope is actually for my dad. It's a surprise. His lounge opens completely onto a balcony overlooking the ocean. Think I'm gonna get him the 4" mak. I think it's the safer option. He really enjoys watching whales etc but has always been really interested in the heavens. I just wanted to check that I wasn't wasting my money.
I hope the mak will give him a decent intro into astronomy and that it will ignite his interst further rather than dampen it.

Thanks again for all the advice.
Do you guys have list of things that he could start off looking at with the 4" mak.
 
Try get him a book with the basics in it (make sure its for the Southern Hemisphere). Its almost impossible to start naming things as there are so many wonderful things to see. Maybe also download a copy of Stellerium for him if he has a PC/Laptop, It will help a lot for finding things.

My most fun evenings are not when I spend hours trying to find an elusive cluster hidden away in the cosmos, but when I just sit back and slowyl scan the scope across the sky, stopping when ever I think something looks interesting, and just going on like that
 
Lucky D said:
The scope is actually for my dad. It's a surprise. His lounge opens completely onto a balcony overlooking the ocean. Think I'm gonna get him the 4" mak. I think it's the safer option. He really enjoys watching whales etc but has always been really interested in the heavens. I just wanted to check that I wasn't wasting my money.
I hope the mak will give him a decent intro into astronomy and that it will ignite his interst further rather than dampen it.

Thanks again for all the advice.
Do you guys have list of things that he could start off looking at with the 4" mak.
Click to expand...

For that purpose a Mak should be fine, even a 4". Just advise him to let it cool for an hour if he wants to have the best views during the night. A good book and planisphere will go a long way in helping him get started.

I haven't come across a SA specific book I like so far, but I use Stars and Planets by Ian Ridpath on a regular basis. The only difference is that some of the constellations looks upside down to us.
 
Hi all. I received a NexStar 114 as a present. I have some difficulties with the device though... I thought it had automatic tracking, but I can't get it to work!

I orientate/align the scope with three objects, and then am able to search for other objects (nebulae, stars, planets, etc), but the scope finds the requested object correctly only the first couple of minutes. Thereafter, obviously the rotation of the earth kicks the alignment off, and I have to re-orientate... Can anyone of you help me with this?
 
ettubrute said:
Hi all. I received a NexStar 114 as a present. I have some difficulties with the device though... I thought it had automatic tracking, but I can't get it to work!

I orientate/align the scope with three objects, and then am able to search for other objects (nebulae, stars, planets, etc), but the scope finds the requested object correctly only the first couple of minutes. Thereafter, obviously the rotation of the earth kicks the alignment off, and I have to re-orientate... Can anyone of you help me with this?
Click to expand...

The major cause for erratic movement of these scopes are insufficient power. How are you powering the scope?

Some things to check:
Have you entered the correct location?
The scope should remember your location between uses. Just make sure that your location is correctly set and that it is in the Southern Hemisphere. I don't know how the handset deals with this, but I'm guessing you can select xx.xx° S, otherwise it will be in the -xx.xx° format.

Have you entered the correct time?
The scope does not remember the time between uses. You need to manually enter it as accurately as possible. An error of even a few minutes will make a difference. Also make sure that it is set to the correct timezone and that no daylight savings is active.

Did you make the tripod as level as possible?
Try to make the tripod as level as possible before use. Although it's not absolutely critical to get perfect, it should be as good as you can get it.

When centering the alignment stars it's best to defocus them so you see a round circle and then center that circle in the middle of your eyepiece. When choosing alignment stars it's also a good idea to pick stars that are pretty far away from each other.
 
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Crusader said:
The major cause for erratic movement of these scopes are insufficient power. How are you powering the scope?
Click to expand...
Batteries... Will the power cord option be better?
Crusader said:
Some things to check:
Have you entered the correct location?
The scope should remember your location between uses. Just make sure that your location is correctly set and that it is in the Southern Hemisphere. I don't know how the handset deals with this, but I'm guessing you can select xx.xx° S, otherwise it will be in the -xx.xx° format.
Click to expand...
I used my GPS co-ords to set it up.
Crusader said:
Have you entered the correct time?
The scope does not remember the time between uses. You need to manually enter it as accurately as possible. An error of even a few minutes will make a difference. Also make sure that it is set to the correct timezone and that no daylight savings is active.
Click to expand...
As close as possible every time, taken from my PC's atomic clock sync.
Crusader said:
Did you make the tripod as level as possible?
Try to make the tripod as level as possible before use. Although it's not absolutely critical to get perfect, it should be as good as you can get it.
Click to expand...
Jip, level as far as I can see...
Crusader said:
When centering the alignment stars it's best to defocus them so you see a round circle and then center that circle in the middle of your eyepiece. When choosing alignment stars it's also a good idea to pick stars that are pretty far away from each other.
Click to expand...
Done that, and, as I said, I can then search for, and find, other stars/nebulae/planets, with 99.9% accuracy. But the scope doesn't track... if I leave it, say on Venus, it finds Venus perfectly, but doesn't keep it in view, and I have to realign the scope...
 
Batteries should be fresh. Also note that rechargeables won't provide the correct voltage. If you have a power cord give it a go.

It seems as if you are doing everything right. The only other option is that the tracking mode might be set incorrectly. I think it should let you select sidereal or lunar tracking. Make sure it's not set to lunar.

These scopes might not have the most accurate tracking but should be able to keep the object centered for at least 5 mins.
 
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