Jump to content

 

1825338873_SNRPN2021banner.jpg.68bf12c7791f26559c66cf7bce79fe3d.jpg

 

Celestron 127 slt HELP!!!!


Recommended Posts

Hi Guys,

I have been out with my 127 SLT, and I really wanted to see the crab Neb (M1), I aligned the scope using the "2 star alignment, but when I looked through the scope I could see anything, Is the because my scope is a 5", or is it because the eyepieces are 9mm and 25mm.

Cheers guys:icon_scratch:

Edited by harriri2000
Link to comment
Share on other sites

I'm no automated telescope guru, so can only tell you about the visual side of things.

The crab nebula (M1) is incredibly faint. I saw it with my 4.75 inch refractor, and it isn't very impressive. Averted vision was needed to actually see it, and all it looks like is a tiny smudged star.

Because of this, you may have just missed it. You may have been expecting a much better sight than what you got. It's fairly tough to see, and one of the most disappointing items on the Messier List.

I managed to see it with my 26mm eyepiece that came with the scope, so I don't think eyepieces are the problem.

Clear Skies

Link to comment
Share on other sites

Another pitfall to be wary of is the alignment of the Nexstar Goto mount. If you haven't got the spirit level centred to ensure the mount is level, or if you've not put your alignment stars bang in the centre of the EP, or if you haven't input the precise lat/long co-ordinates for your location, then you may find that when you slew to a target that you punch into the Goto controller the target may actually be outside the field of view. I've found that alignment errors aren't too much of a problem if the target is obvious i.e. Saturn or a bright/large star cluster, but a small faint object like the Crab Nebula could easily be missed.

Link to comment
Share on other sites

Things are going to be against you with M1 at the mo. If you wait until it's dark it is far too low in the night sky and if you don't wait it's not dark enough due to the fact that you're looking west, where all the remaining sunlight is.

If you're trying to find dimmer objects with a 127 you should really be limiting yourself to ones which are at least 45* in altitude and only after it's got fully dark.

FYI there are some globular clusters which are at a good altitude by midnight and these look quite nice through smaller scopes.

Hope that helps :)

Link to comment
Share on other sites

A couple of things you need to do : think of them as 'hygiene' factors.

1. take careful note of, and record, the dimmest star you can see with the naked eye : this will give an important clue to what you are likely to pick up on a given night.

2. Once you've done your two star alignment, check that the mount is actually pointing correctly in that part of the sky you want. So for M1, go to Alnath, Aldebaran or Betelgeuse. If that's properly centred, you can be reasonably sure you're pointed at M1 when you select that as a target.

3. Pointed at your 'invisible' nebula, tap the tube gently to create slight vibration, or use the up/down left/right buttons to move the scope very slightly. The eye will more readily pick up the nebula at the limits of discernment when it's apparently moving.

4. Persevere. Successful observation needs a substantial input from the observer. It's a good telescope - you will be able to see M1 with it, but as Paul suggests, not necessarily this season.

Now go get those globulars.

Edited by neilmack
Link to comment
Share on other sites

As the others have said, M1 is not impressive at all in smaller scopes and, if there was any light pollution or moonlight about, you would have possibly been looking right at it and not noticed it !.

Edited by John
Link to comment
Share on other sites

Hi Richard

At this time of year from your location with a small scope TBH you'll be lucky to see it at all.

Wait until next Autumn/Winter when it's high in the sky.

Your scope will show M1 but you've gotta give it a chance.

As Revs said try some better placed Globs. Much more rewarding at the moment.

Good hunting and clear skies

Regards Steve

Link to comment
Share on other sites

M3 springs to mind, but have a look on Stellarium and you'll see there are a few.

As for Summer observing, I wouldn't say Summer is poor. Some of my best nights were last August when I first got my Mak. I remember having clear skies every other night. Yes, seeing isn't as steady as a good winter and it was only dark for a few hours, but I'll take that over this winter we're having now any day.

Link to comment
Share on other sites

Cheers guys,

George I see you have a 102 slt, how do you narmally align you scope, which option do you use, I normally use the 2 star alignment but I'm finding that is off alignment quite a few times.

I usually don't need to worry about levelling the mount as my usual observing position is fairly flat. Once I've powered up the GOTO, I'll reset the date and time (always remember it's the US MMDDYY format). I then select the 3 star alignment and use 3 objects as far apart as possible and ideally marking out a roughly equilateral triangle in the sky. Each time i align I roughly centre it with my red-dot finder and 25mm EP and then put in my 9mm and centre it again for more accuracy, then back to the 25mm, ready to align the next object.

Once it confirms successful alignment, I'll GOTO a familiar and easy test object such as M44, Pleiades, or Saturn, to ensure it's behaving itself. That test will also tell me if there are any inaccuracies in alignment if the test object is off to one side. I'm usually happy if the test target is somwhere in the field of view.

The only times when I've had problems with alignment it's because I've goofed up with entering the date/time correctly or the surface is uneven and I'll have to fiddle with the spirit level.

Link to comment
Share on other sites

Also don't forget to set the timezone as 00:00 and set the daylight saving option to 'Yes' :)

You can redo the alignment on individual objects once the initial alignment is done, at least you can with the SW version of that mount. If you're finding objects a bit out, fine tune to the object and then hold the 'ESC' button and it should say something like 'REALIGN OBJECT', then press 'ENTER'. This should add accuracy as you go.

EDIT: Oh yeah, I found leveling the mount to be critical for accurate tracking/aligning.

Edited by Revs
Link to comment
Share on other sites

Haven't tried it yet with my scope (same as yours) as I thought it might be too dim - BUT - I know I will have a go - I'll let you know if I have any more luck - on the aligment issue - did you do a goto on another object during that same session and did it line up ok?

Link to comment
Share on other sites

Hi MM,

Well when I couldnt find M1 I thought there was something wrong with the scope/alignment so I tried it on the Polaris, I was quite shocked how dim that was, now thinging about it the alignment was still out. next time I'll do as GeorgeB said centre with the 25mm then centre with the 9mm to get a better alignment. also due to the moon being high and bright at the moment it still quite hard to see things.

I have tried to look at a couple double stars but due to not really knowing what I'm looking for Im not sure if I have seen them, is it just 2 stars that are close together?

Thanks

Link to comment
Share on other sites

I have tried to look at a couple double stars but due to not really knowing what I'm looking for Im not sure if I have seen them, is it just 2 stars that are close together?

Basically, yes, I think I'm correct in saying that there are two types of double stars, visual, which is where, when using a scope, a single star actually appears to be 2 stars very close together although they are not linked in any way and may in fact be millions of miles apart but just lying in the same visual line from earth, and there are binary stars which again appear as a single star 'till seen through a scope - these stars are actually orbit each other - there are other types such as eclipsing binaries and spectroscopic, but I'm getting way out of my depth here!

Anyway, a good double to have a look at at the moment is Castor - very easy to find and very obviously a double - Good luck

Someone may come along and totally debunk what I've said - if so, we'll both learn something new!

Link to comment
Share on other sites

I have just been reading the sky at night mag, and it says that for GoTo mounts you have to start but align the scope to Polaris first, is that correct for the Celestron 127 slt as well, the reason I say this is that the article is talking about SW GoTo mounts (and I know that celestron and SW mounts are make by the same people)

Cheers

Link to comment
Share on other sites

I have just been reading the sky at night mag, and it says that for GoTo mounts you have to start but align the scope to Polaris first, is that correct for the Celestron 127 slt as well, the reason I say this is that the article is talking about SW GoTo mounts (and I know that celestron and SW mounts are make by the same people)

It's only equatorial mounts with GOTO that you must align with Polaris (or the celestial pole) first. The Nexstar alt-az mounts that we both have don't require it - though there is nothing to stop you using Polaris as one of your alignment stars if you wanted.

BTW - I've acquired a Mak 127 myself this week, which I'm using with my Nexstar mount. The problem I've got is that it doesn't sit quite flush in the dovetail joint as it's slightly larger than the 102mm refractor that came with it, which means I can only do single star alignment. Not a big deal as I only plan to use it for the Moon and planets and I was planning on eventually buying a new mount for it anyway. The view of Saturn through it is awesome :)

Link to comment
Share on other sites

HI Richard

As GeorgeB said you don't have to use Polaris with our 'scopes, In fact I find it quite tricky to align to as it's very high (end up my knees to get it in finder scope) and quite dim - I tend to use Regulus, Betelgeuse and Capella as they are well placed from my garden

Link to comment
Share on other sites

Well went out tonight had a great time I saw Saturn and 3 moons, I saw ISS flying over but was going way to fast to get it in my sight, got a couple globulars as well even nex5 door got involved, all in all a fab night. I used the two star alignment and changes the EP around as got tought by you guys, and it se it be much better. Tell me once you have align one star are in a race against time to complete the second star alignment

Link to comment
Share on other sites

It should not matter how long you have between aligned stars, the software should calculate the 2nd star position based on the actual time when you centre it.

I tend to use Polaris as the first star ( easy to find) and currently use Arcturus.

Once aligned I GOTO an easily identifiable object such as Saturn to check everything is OK.

Clear Skies

Paul

Link to comment
Share on other sites

Hi,

The Seben zoom works fine with my SW 102 MAK although the FOV is only 40 degrees at the 24mm end. Not so good with my 80F5 refractor.

I like the convenience of being able to zoom in on an object to find the best contrast.

The GSO 32mm Plossl give me the widest FOV without spending as much on an eyepiece as I did on the scope :) I'm very happy with it's performance bearing in mind I'm no expert.

I'm considering a short focal length eye piece specifically for planetary use - not decided what yet.

Clear skies

Paul

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.