Star Alignment on Celestron 127

[ak785]

I've just come in from my first trip outside on the patio with my Celestron NexStar 127. I went out full of confidence, with semi clear skies. However, it didn't go quite as smoothly as I had hoped. The 127 comes with "star align" the general idea as I understand it is to point the telescope using the finder scope at three of the brightest stars in the sky, follow the instructions on the controller and it should have an understanding of the objects that are visible in the sky.

I don't know if I was meant to do anything else before I tried to align, but I followed the instructions gave it my position (nearest City to me that was in the database), date and time. I also had the red dot laser (which is cool) dead centre on the stars that I wanted to align to, they seemed to be bright enough I would have thought. But it didn't align it kept saying unable to align and to try again after three attempts the clouds came over again and covered everything up so in I came.

Its difficult to see where I've gone wrong? I don't know whether the finder wasn't lined up with the scope itself therefore that's why it couldn't align, or if one or two of the stars I was choosing simply weren't bright enough.

[Freddie]

Did you enter the date in the US format i.e. month, day, year? Also have daylight saving as "no"?

[ak785]

Did you enter the date in the US format i.e. month, day, year? Also have daylight saving as "no"?

Hm i'll double check how i entered the date, but I had Daylight saving set to Yes as i think it was that by default - would that throw it off?

[ak785]

I also accidentally moved the red dot laser focus thing and i'm not sure how to get it back to where it was by default

[M4lcs67]

I own the 127 SLT and I found it difficult to align at first. The instructions are a little hard to follow as well. Rather than inputting you closest city, how about choosing your actual co-ordinates to get it even more accurate? Also, as mentioned have you inputted the date in the US format?

[Freddie]

For daylight saving, yes, you will be an hour out which is 15 degrees out across the sky. Obviously if you had the date in the wrong format it will think it's October so will be a LONG way out !

[ak785]

I own the 127 SLT and I found it difficult to align at first. The instructions are a little hard to follow as well. Rather than inputting you closest city, how about choosing your actual co-ordinates to get it even more accurate? Also, as mentioned have you inputted the date in the US format?

I've just turned it on to check and i've entered it in UK format - so the telescope would have been looking for the sky as of 3rd October (that's frustrating). It has now clouded over totally, i've never been so annoyed with clouds all last week and there was about 30 minutes tonight where it was somewhat clear, Jupiter was clearly visible, but i couldn't get it to align.

I hope it was just the date that was throwing it off rather than me touching the red dot thing

[ronin]

DST is presently No. soon to change.

Date is Month, Day, Year = US format.

Check the Timezone, should be 0, default may be Pacific coast as in zone 8 I think.

Postion is possibly Longitude then Latitude so something like 1.5W and 54.7N, the West bit may be negative -1.5 not W, depends on how it expects the value. Cannot recall which value the Celestrons expect first, and it is easy to get them the wrong way round.

May be better to gather all the information together, write it down and start again.

If something is incorrect it can be a real pain to make sure you get and correct the right bit.

Have fun.

[ak785]

DST is presently No. soon to change.

Date is Month, Day, Year = US format.

Check the Timezone, should be 0, default may be Pacific coast as in zone 8 I think.

Postion is possibly Longitude then Latitude so something like 1.5W and 54.7N, the West bit may be negative -1.5 not W, depends on how it expects the value. Cannot recall which value the Celestrons expect first, and it is easy to get them the wrong way round.

May be better to gather all the information together, write it down and start again.

If something is incorrect it can be a real pain to make sure you get and correct the right bit.

Have fun.

Funny you mention that - i've just written the date format, DST to No, and the lat/long for my location all on some paper - ready for clear skies if it doesn't work i'll be on here from my mobile

[faulksy]

good chance it was the date format

[ak785]

Do i need to be concerned about the finder scope and me moving the focus dial?

[M4lcs67]

Keep persevering. You'll get there. We have all been there at some time of another. Blimey. I had been waiting months before I had the opportunity to give my C9.25 it's first spin. I would suggest getting the red dot finder aligned with the scope in daylight. Focus the scope on a distant object and align the rdf to that.

Don't wish to alarm you, but you may find that the rdf gives up the ghost pretty quickly and you may find yourself having to replace it. They are inherently unreliable.

[ak785]

Keep persevering. You'll get there. We have all been there at some time of another. Blimey. I had been waiting months before I had the opportunity to give my C9.25 it's first spin. I would suggest getting the red dot finder aligned with the scope in daylight. Focus the scope on a distant object and align the rdf to that.

Don't wish to alarm you, but you may find that the rdf gives up the ghost pretty quickly and you may find yourself having to replace it. They are inherently unreliable.

To be fair it looks like it was meant to be replaced, just the fact that its in its own separate bit and screws in / out easily. Stupid question but it seems everything else in this game can be upgraded, can you get advanced RDF's?

[M4lcs67]

I replaced mine with a Baader SkySurfer lll. Very much like the supplied one, but far more reliable. It is around £23 I think.

That is the beauty of this game we call astronomy. You originally start off with the basic scope, but as time and finances allow, you can upgrade pieces. Firstly you have a great OTA with the 127 SLT, so that is a good starting point. Another thing you will wish to do in time is upgrade the eyepieces that came with the scope. The supplied 25mm is actually pretty good. The 9mm however is rubbish and I personally would look to update that as soon as funds allow. I like Baader Hyperions myself (£100 a pop), but you don't have to spend that kind of money. There are many different makes, models and types of ep to choose from. Others will give their own personal opinions as to what they think.

[ak785]

Sorry what's the OTA abbrev? I've noticed people advising to update the eye pieces I was looking at the Celestron Xcel ones which are £79 but ill seek advice before I go spending that kind of money.

A few of those eye pieces and your up to the cost of the scope itself.

My SCP880 should be here tomorrow with a 1.25" IR Filter so hopefully I can get some clear skies get aligned and then capture something I don't care how bad it is ill post it up.

Snowing here at the minute but there are patches of clear skies. It was quite the learning curve last night I got out with the scope 30 minutes and the clouds had covered everything up again.

[Steep]

If you're thinking of replacing the rdf, have a look at either the Rigel Quickfinder or the Telrad. I have a Telrad on my 127 and it's the bees knees, far easier to use and much more reliable than the supplied rdf. The Rigel wasn't around when I bought it otherwise I might have chosen it as it's neater.

/edit OTA = Optical Tube Assembly = the scope by itself.

[ak785]

Ill take a look now at the Telrad - how's it easier to use is the rd clearer or ?

[ak785]

Oh wow this looks great http://www.firstlightoptics.com/finders/telrad-finder-astronomy.html

[Steep]

There's no red dot, you see a set of rings instead and line up your target in the centre of the smallest one, it also goes a lot dimmer. My main problem with the rdf was it was either too bright and obscured the target or it was off altogether.

[Steep]

Suppliers always picture the Telrad the wrong way round, the business end is with the glass screen sloping towards you, one reason why I think the Rigel might be a better choice on smaller scopes.

[ak785]

I agree with that - it does obscure the target. The telrad looks immense, easy to navigate with due to the circles.

[robhatherton]

Is it possible to mount something like a travelscope 70 on the SLT 127 and use that as a finder? And wouldn't the main scope have needed to be aligned on the stars for the process to work?

[E621Keith]

The Terlard finder is huge, a Rigel may be better for a small scope like the 127. IMHO, the finder Celestron gave you is good enough for initial alignment. A high quality finder like Rigel and Terlard isn't necessary for a GOTO scope.

As other mentioned

1. DST to OFF. (I leave it off all the time and use GMT/UT even in the summer)

2. Time zone to 0

3. Date in US format MM/DD/YYYY

4. Longitude and Latitude in Degree, Minute, Second, format

Other things

Check your finder is align to the OTA (optical tube assembly - the 127 Mak) ('Telescope' refers to the whole thing, OTA and mount)

During alignment, use the RDF (red dot finder) to point your telescope, then centred the object in your telescope's eyepiece. The RDF alone isn't accurate enough.

When you point it at 3 stars, point it to three widely separated stars with different elevation. Your scope should have rotated around 270 deg by the time you finished.

Good luck

[Steep]

A high quality finder like Rigel and Telrad isn't necessary for a GOTO scope.

Maybe not but the supplied rdf is very poor quality and one of the above makes life so much easier as to be well worth the £35 cost. I consider mine to be one of the best investments I've made.

@ robhatherton - It would be possible but serious overkill probably need a finder scope for the finder scope.

[robhatherton]

Thanks Proto Star. The Travelscope 70 has a magnification of 20x with a 20mm eyepiece and I can usually aim it directly at something without needing the finder, just sighting along the barrel. That's why I asked. Cheers!