February Beginners Viewing Session

rmcpb (Rob) · #1 15-02-2005, 12:25 PM

Well last night was lovely and clear and we just happened to have an unexpected guest. He saw the scope out in the yard and asked a few questions then finally got to the point - could I show him some things up there?

What a good time of year for this

We started with

Saturn and the whow factor kicked in instantly - cloud patterns and the rings at that range!!
The moons of Saturn were a real treat - he never thought that it would be possible to see them
The Orion Nebula was next and we spent some time in there counting the stars and generally talking about nebulae
Pointed out the LMC - a naked eye galaxy!!
This lead to the Tarantula Nebula
A quick hop over to Crux and we split alpha crux - that was fun as it looked like a single star in the binocs
The Jewel Box had to be next - he couldn't believe the colours
Up to the Five of Diamonds in Carina
Then over to Eta Carina
Omega Centurus was up high enough be then so he was gob smacked by that little one - told him to start counting the stars
By this time Jupiter was up and the fact that he could see cloud patterns on something half a billion kilometers away just blew him out of the water

This little tour just pointed out to me how spoilt we are here with fairly clear skys and some of the best astronomical views available.

Not a bad introduction for someone who just dropped in.

ving (David) · #2 15-02-2005, 12:47 PM

good on ya rob

nothing like showing newbie stuff

and was shuch a clear night last night too... too bad it was valentines day. after dinner when we walked out to the car I was looking up at the sky and I said to cheryl "is'nt it clear tonight..."

she said "dont even think about it mister!!!"

LOL

we got home and I looked at the moon and told her how amazed I am every time i see it. she admitted that after 35 years of seeing it it's worn a bit on her... :/

oh well...

rumples riot · #3 15-02-2005, 03:56 PM

Hopefully Rob you have inspired another to join in the wonders of the universe. Sounds like you had a good night, nothing but cloud here and of course the scope is currently packed away for construction.

blackpearl · #4 15-02-2005, 08:40 PM

Just what I need to know when the telescope arrives (12' Dob) Are these things easy for newbies to find?

janoskiss (Steve H) · #5 15-02-2005, 09:56 PM

Blackpearl, Yes they're easy to find, if you have charts or software to generate them. They are also shown in the monthly sky map in the Aust. Sky & Telescope magazine or the Bintel newsletter. And they are fantastic. Just keep in mind that some of them are huge. When I first looked for the tarantula and eta carina nebulas, I was looking for something much smaller, and I was not sure if I found them or not. That was in light polluted Melbourne though. At a dark site, they were obvious... LMC (i.e., Large Magellanic Cloud, if I got the spelling right) is even bigger, about 10 degrees in size.

Do you own a small scope or are you starting out with a 12" Dob???

MiG · #6 16-02-2005, 12:46 AM

"Just what I need to know when the telescope arrives (12' Dob) Are these things easy for newbies to find?"

I have found that even with my 60 mm Tasco, that just wandering around the milky way with 28x (low) magnification lets me see some cool things. Accidentally finding a nice cluster for the first time is quite exciting. Ditto for Saturn. I thought I was looking at a bright star before I saw it through the scope.

At the moment Jupiter is really easy to find. It rises in the east about midnight and it's the brightest thing in the sky. You'll easily see it's moons.

Can't wait until my 10" Dobsonian comes. The 60 mm refractor has served its purpose. I got it second hand just to see whether I really want a telescope or not.

RAJAH235 · #7 16-02-2005, 05:15 AM

Rob, keep up the good work. More AA's req'd. Blackpearl, If I may ask, do you have a *Planisphere*? It will help you to find your way around. B & T has them. Chandler (large version), about $23.00. Oh, and a red LED torch.
Just the facts m'am.

rmcpb (Rob) · #8 16-02-2005, 08:27 AM

Blackpearl,

Yep they are all easy to find, that is why they are on my list of newbie stuff. They are great to look at and, except for the planets, were observed at between 40-49x magnification. Actually the five of Diamonds is better in binocs as most scopes field of view is too narrow. For the planets about 133x is enough to see most of the features but if the seeing will support it of course you can up the mag.

One point, before you even take your scope out check the collimation I think your new scope is probably an f5 so collimation will be quite critical. If its out the images will be disappointing.

Cheers

ving (David) · #9 16-02-2005, 09:15 AM

the "5 diamonds" (never heard of it being called that) fits in my 30mm sv nicely

to ppl who are getting a new scope: get the GSO 30mm sv too! you wont regret it...

rmcpb (Rob) · #10 16-02-2005, 12:14 PM

Quote:

Originally posted by ving
the "5 diamonds" (never heard of it being called that) fits in my 30mm sv nicely

to ppl who are getting a new scope: get the GSO 30mm sv too! you wont regret it...

Good advice but most get the scope as issued and a superview is not one of the eyepieces supplied besides I think the bino view is great

blackpearl · #11 16-02-2005, 09:21 PM

Thanks guys
Great information. Yes, I'm starting with the 12' Dob, understand about the size but can't resist a bargain - I will grow into the telescope.
Have been a regular visitor to our local telescope -Gilgandra Observatory and it is awesome, just love it.
Ordered a laser collimator (?) with the scope ( I read these posts and pick up all sorts of information)
Getting binoculars as well (hope to attach to my camera tripod)
Have bought the Astronomy 2005, and both the S&S and S& T magazines
Need a red LED torch - are these available in Dick Smith?
The 5 diamonds - is this the 5 sisters/pleiades?
One more quesstion
What is the fan for in the Dob?

iceman (Mike) · #12 16-02-2005, 09:33 PM

Wow! A 12" for a first scope! Try not to be overwhelmed when you get it.. it's absolutely huge if you're not used to what they look like.

Laser collimaters can be hit and miss, I prefer the cheshire kind. But you might do ok with the laser, just get some advice from those who use them because they can be tricky and you could spend all night trying to fix a collimation error that doesn't exist.

What binoculars did you get? If they're cheap 10x25's or similar, it's unlikely they'll have a tripod mounting screwhole. If you got a decent pair and they do have this, you'll still need to get a tripod adapter - this screws into both your binoculars (at one end) and the tripod head on the other. They're only around $15 or so at a few places.

Some good magazines/books you got there, that's pretty much all you'd need to get started, except for a planisphere. I recommend you get a planisphere which has a wheel that spins around to match up the time with the date, and has north on one side and south on the other.

Red LED torches can be found in most hardwarey/electronicy type shops, or even Australian Geographic shop. Or, get some red cellophane and tape it over the front of a whitelight torch for starters.

The fan is to aid in cooldown type for the primary mirror. If there's a large difference in temperature between the outside and inside the tube (and the mirror glass), you'll get nasty currents flowing through your tube as well as your primary changing shape/collimation as it cools down and contracts or expands. The fan will help your mirror cooldown and reach ambient temperature a bit faster, meaning in theory you don't have to leave it (the scope) out as long to cooldown before you start observing.

Anyway you'll have a ball! can't wait to read your first light report!

RAJAH235 · #13 16-02-2005, 09:49 PM

Hi Blackpearl, guess who. The *7 sisters*/ Pleiades, is part of the constellation of TAURUS, the bull. It represents the heart of the bull. Actually there are about 50 stars in the cluster. The main ones are BLUE giants. HST pics show nebulosity around most, but this I have read, is not associated with the cluster. Rather they are just passing thru it.
The fan is used to assist in cooling the main mirror down to ambient temperature so that the image is not affected by the heat coming off it.
I make the red LED globes but it's probably easier to buy a torch from Bintel. Maybe someone could suggest something?
Just the facts m'am.

blackpearl · #14 16-02-2005, 09:52 PM

Started out wanting my own telescope to take photos.
Started to research your site, magazines etc. and realised that it was a tad too technical for me. Looking at photos of Dobs I thought that a Dob needed to sit on a table to get it high enough for me to see through it!!!! Saw them in Bintel in the city in Sydney when I visited in Jan - well you can imagine how I felt!!!!. Tested lifiting the 8" and 10" and the 12". Isn't tooooooo heavy! Realise its a bit big for me but Dad has worked out the logistics of a trolley -for the backyard and I have measured the Toyota and it should be OK. Lots of black sky out here near Coonabarabran.
Just love the photos of peoples telescopes and the stuff needed for those other scopes and I think I've made the right decision. Maybe when I am more experienced I may change my mind.

janoskiss (Steve H) · #15 16-02-2005, 10:05 PM

Blackpearl, Congrats on being brave enough to get the 12" beast as your first scope!

With LED torches, make sure they're really LED. The ones with red screen over a normal lightbulb are not good enough; they're better than ordinary torches but still interfere with your night vision. Cellophane over a torch would be the same I imagine. Get one of those red LED rear lights for push bikes from a bargain shop (for under $5). They're perfect.

I also got a laser collimator with my scope. I assume you got a return beam one... When you get it make sure the collimator itself is collimated. It is if rotating it in the focuser does not shift the return beam. If it's not collimated, do not attempt to collimate it yourself if you can return it (I tried and busted the laser, even though I was very gentle). If you bought it from Andrews, you won't get a user's guide. Get one here from Orion. They also have manuals for GSO scopes you might want to check out.

Even if it is well collimated, the laser alone might not be good enough. Check out the barlowed laser method.

jackenau · #16 16-02-2005, 10:13 PM

Way to go Blackpearl. 12" dob is definately a scope to be appreciated. Is a great scope and will give you many hours of enjoyable viewing, that can only be enhanced by the ep selection.

The other Ken appears to be more than happy with his, judging by his reviews.

Am only new to this myself and started out with a 4" then 6" reflector scope and am very happy with my 12" dob.

As you have mentioned the scope is reasonably easy to be moved around the yard on a trolly. (be very wary that vibration when moving causes nuts and bolts to come loose, check regularly).

Doesn't fit relatively easilly in most sedans. (I have a Toyota and yes, I can fit it in, but it takes up the front passenger seat and rear seat. The passenger has to sit behind me)

All this aside THE VIEWS are extremely good and satisfying, and are probably the best before moving on to a higher and more costly side of the hobby.

There are always additions to enhance ones viewing and tracking capabilities.

KenM (happy dob owner)

janoskiss (Steve H) · #17 16-02-2005, 10:20 PM

Another thing, it's not "5 diamonds", it's "5 of diamonds" as in cards because of the X pattern 5 of the stars make. Aka IC2602 and Southern Pleiades. It was featured in Jan/Feb AS&T. It's nice and bright, mag 1.8.

ballaratdragons (Ken) · #18 16-02-2005, 10:51 PM

Hi Pearl,

The fan works a treat. I put the 12" out at sunset and it got pretty warm.

By dark the scope was very cold to the touch but the mirror was still warm (felt it through the back).

Normally you would wait about an hour or so for such a large mirror to reach the same temperature as the air around it (ambient temp).

I just switched the fan on and in 5 minutes the mirror was freezing cold.
I switched the fan off and within 1 minute the air turbulants in the tube had gone and didn't affect the views.

If you need to work out the collimation method of the primary mirror, It is covered in the thread 'GS 12" mirror cell'. I couldn't work it out and Geoff and Markus helped solve it.

It's not very hard to find basic things in the sky, planets, large nebulas etc, but other stuff can be a bit hard (without maps, planispheres etc.). But I reckon half the fun is trying to find them. I don't use star maps very often but only because I spent a long time learning constellations by eye.

To start with, just use the southern star maps in the Astronomy magazines. They are nice and simple. When you get used to zooming around the sky with them, the better maps won't seem so overwhelming.

I also recommend the GS 30mm Superview 2" eyepiece. It's magic!

Hope you get your 12" soon.

gaa_ian (Ian) · #19 16-02-2005, 11:32 PM

Good choise Blackpearl

I would have gone the same way at the start had they been available then !
Coonabaraben Eh

I can see why you were insired to get the bigest scope you could.

ballaratdragons (Ken) · #20 16-02-2005, 11:44 PM

It's not too late to go up in size Ian.