First Light with Celestron 127 SLT

[TheQuietEarth]

Thought I'd make a new post as my first telescope has achieved first light and I managed to align the scope properly to get the GoTo system working - and I'm very happy as a consequence.

My dad shared the experience with me and the first object we observed was Jupiter and four of its moons. I took the scope outside and left it for an hour to cool down. I also took left the eyepieces in their boxes but exposed to the outside air for the same amount of time. I take it they need time to cool down too, is that correct?

My first attempt at alignment went wrong, probably because I took too long to locate Pollux in the finderscope and eyepiece. I used Capella and Pollux on the two star align procedure. When I asked it to go to Jupiter it was off by a degree longitudinally.

Anyway, we used the finderscope to manually slew to Jupiter and we got great views through all three eyepieces - 25mm & 9mm Celestron Plossls, and a 12mm BST Explorer. The best views were seen through the latter eyepiece.

I then tried the two star alignment again, ensuring that the time was correct (set the time first and then waited for the clock to strike that time before hitting Enter immediately) this time. It didn't ask me to re-enter the long/lat coordinates and I felt confident that I'd entered them correctly the first time round. I chose standard time and the Universal Time Zone options and then chose Capella and Regulus on this occasion. The handset said it was a success, but it had said the same the time before and been off by quite a distance, so I asked it to find Jupiter and this time it was almost spot on to the extent that I only had to gently slew the scope a tiny amount to the right to get Jupiter in view inside the 25mm Plossl. Once in view the tracking system kept it that way for as long as we observed it (over 10 minutes). It found other targets with ease and the majority of them were in view as soon as the GoTo system stopped slewing. Is this normal operation for a GoTo scope, i.e. some targets will require a tiny adjustment to centre the view inside the EP?

We were beginning to get cold so decided to call it a night with two last observations - M35 and M37. Both were easily found and we could make them out in both the 12 and 25mm EPs.

I have fallen in love with astronomy and every day I find myself thinking about it and cursing the skies for being filled with clouds.

If the weather had been consistent this week then we'd have travelled down to Galloway Forest Park as it's only an hour and a half away, but since it hasn't been great out we've decided to take the scope up to some moors between Glasgow and Ayrshire. I'm already very excited about it and the kids seem giddy with excitement too.

Now that I've seen how the small FOV can restrict viewing of certain Messier Objects I'm thinking about how I can see more DSO with my Mak and whether buying something like the 32mm Celestron Plossl will help me achieve that. If I buy it next month my budget will be £50 max, whereas in May I'll be able to afford up to £100 for a 30+mm eyepiece.

ps After viewing the moon I think it'd be a sensible idea to purchase a moon filter.

[Steep]

I think I've read around here somewhere that 32mm is about as wide as you can go with the 127. It's well worth saving for longer and getting the best eyepiece you can afford and from my own experience with the 127 the 9mm was the poor one so I replaced that first.

Eyepieces don't need to be cooled down and are actually more comfortable to use if your eyelids don't stick to them

With goto if you set it up initially with your most powerful eyepiece i.e. the 9mm it will be more accurate later on. I have found goto to be ok but never perfect in finding my target but as long as it ends up in the eyepiece somewhere you can always manually slew over to it and the scope will follow along after that. I've always used 3 star align believing that the more reference points it has the better and it's generally been good enough. Make sure you have enough juice to last the session, the goto will do crazy things if it loses power, likewise if you use a powertank or mains power supply hook up the lead so it doesn't fall out.

[michael.h.f.wilkinson]

Nice report! These little maks are great scopes, both on planets and deep sky (except from a handful of very wide-field objects). A 32 Plossl can be used and gives the widest field available. The alternative is to go for a 24-25mm ultra-wide angle EP, which gives the same true field of view, at a higher magnification. This has the advantage of getting darker sky backgrounds, which can help in a suburban surroundings

[Tyr]

Congratulations on your first light!

I have the same scope and I always found the named 2 star align to work well for me as well, it had the added benefit that I learned the names of some of the brightest stars as I went

I felt that if the object was in the field of view of the 25 mm eyepiece when the scope had stopped slewing, that was pretty good, I wouldn't expect it to be in the field of view of the 9mm eyepiece (but maybe I'm just not great at the alignment?).

If you to want to try and increase the accuracy of alignment a bit you can find the alignment start with the lower power EP then swap in the higher power one and centre it in that as well before clicking confirm the second time (I think you click once for found in finder then again for centred in EP from what I remember). This seemed to help a bit for me.

For low power objects I decided I wanted to try a longer focal length eyepiece soon after I got the scope

I first got a 32mm GSO Plossl (52 degree EP like the bundled celeston EP's), which I got for this kind of thing and it works perfectly well, giving me 1.1 degree field of view. It wasn't expensive and seems well built, but to be honest I don't use it much now at all.

Since I have purchased a 25mm Celestron XCel-LX (60 degree EP like your BST), which gives me a 1.0 degree field of view, but I prefer it since it gives me greater magnification and I find the design comfortable, this is probably my favourite eyepiece when used with the 127 Mak for looking at medium sized deep sky objects. It's also well made as it the BST which I own. There is a 25mm version of the BST eyepiece you already own, which would give the same field of view and magnification.

I considered a Baader Hyperion 24mm EP which has an even wider field of view, however it was a bit more expensive at the time and appears to have increased in price more since, but it's still quite appealing to me.

The field of view tool here is quite interesting, it has the Celestron 127 SLT in the list of telescope and if you click the link to switch it to visual mode you can get a feeling for what your field of view would look like with different eyepieces.

http://www.12dstring.me.uk/fov.htm

It's best to pick an object you are already familiar with though as the photographic level of detail (due to long exposure) is not something you're going to see visually.

However you can fit a lot of deep sky objects in the field of view of your existing eye pieces though, things like globular clusters should be really nice with either the 25 or 12 mm eye pieces, keep an eye out for M13 once it comes around

Objects that are really big such as M45 the Pleiades and M44 the Bee Hive, I find better to look at with my binoculars anyway. Alternatively you can just pan around a bit once you've found them with the the scope and the 25mm EP.

Best of luck with your new scope there's plenty to see

Tyr

[TheQuietEarth]

Thanks for the responses, tyr, Michael and Steep.

Steep I tried your suggestion to use the 12mm to configure the alignment and it was indeed more accurate tonight. I then switched that EP out for the 25mm while looking at Messier objects. There were some we couldn't see but I reckon that's because of LP (M105, M95 and M96). From our garden we can only see South East through to Jupiter in the South West. I should take the scope out the front and see what I'm missing in the other directions.

Michael that's a good point about the differences between the 25mm and 32mm eyepieces. Hadn't thought of it in terms of darkness and TFOV - just in terms of FOV resulting from the lower magnification that a 32mm Plossl will give me. One of the Baader Hyperion Ultra Wide EPs would be a great addition to my setup. Thanks for the help and advice.

Tyr thanks for sharing your knowledge of the scope and astronomy in general in such a detailed and helpful post. I used the 12 Dimensional String FOV simulator to decide between the 127 and 130 SLT scopes, with the 127 seeming to suit my needs better than the 130.

Thanks for informing me of the GSO Plossls. The X-Cel LX are the eyepieces I've been thinking about the most recently. I really like the look of them and they are well under £100 which will allow me to buy them before the end of May. Still, the Baader Hyperion EPs look brilliant and for the small difference in price (£30) maybe I should just be patient and save up. Could always see if I can buy them second hand.

In General -

While my dad and I were viewing last night we noticed something a little odd. I've seen satellites pass overhead on numerous occasions, including some memorable views of passing satellites over Ben Nevis.

But last night I seen something move more quickly across the sky then anything before. It appeared as a bright light just above the southern horizon at sometime between, say, 1930-2015, but probably closer to 2000 and beyond. We noticed it because it was behind a tree with no branches and rising very quickly into the sky. As it got higher it became diffuse and more difficult to see the bright light it had produced earlier. Beyond Regulus it was almost invisible, more a tiny smear moving against the blackness of the sky at some speed. It moved from just above the southern horizon to directly overhead and then beyond towards the north in under 25 seconds. I'll have a look on Stellarium to see if there was any satellites in that kind of orbit. Is that a normal orbit assuming it was a satellite?

[Ohmless]

http://www.heavens-above.com/ is a good site for looking up satellites and for trying to catch the ISS

happy you enjoy the new scope.

[M4lcs67]

Strikes me that you had a brilliant first night. And the beauty is that the only way is forward as well. More things to see. More experience to gain. This astronomy malarkey is awesome and thank goodness I found it as well. I still gaze in absolute wonder at the night sky on and lovely clear night. I will never ever get used to it.

[TheQuietEarth]

Thanks Ohmless and M4lcs67.

I was using Stellarium to check which satellites were overhead that night. There was a Cosmos passing overhead from South to North within the time frame I mentioned in the previous post. That's probably what we saw. Seemed faster than any satellite I've seen before though.

Last night I took the scope up to my friend's house to let him and his son observe the sky with it. They were in awe at seeing Jupiter like that. Was so pleasing to see their excitement. The GoTo only takes about five minutes to assemble and then a few minutes more to align. Brilliant system and I'm very happy that I bought it rather than a Dobsonian. I don't think I would have been able to find objects like Cor Caroli or other visible Messier objects without the GoTo system.

Can anyone who bought a brand new 127 or 120 SLT tell me if their scope's primary mirror appeared dusty out of the box? As we were setting it up last night my torch illuminated the primary and I noticed that it was dusty looking and slightly spotted. The corrector also has this white thread-like filament embedded in the glass. I thought it was dust and used a blast of air to blow it off but then realised it was actually in the glass. Similarly, there's dust impregnated in the glass at the front.

[Stargazer_00]

Sounds like you had a good night

I see on your picture that you use the scope on decking. This tends to lead to quite alot of wobble at the eyepiece, especially at high magnifications. You might do well to gt a bag of sand or some other heavy dead weight and either put it on the eyepiece tray or hang it from under it centrally. This added weight will help with and vibrations making it up to the eyepiece.

Clear skies!

[TheQuietEarth]

Thanks for the tip, Stargazing00. Yeah the vibrations can be annoying but I find that they stop quite quickly and that the GoTo tracking seems to smooth them out. It was actually worse on my friend's concrete path in his back garden. I didn't want to sink the mount into his grass as it looked quite sodden, so we plonked it down on the concrete only to find the vibrations quite extreme. They did settle but my friend has balance issues owing to a bad car accident years ago. He was really struggling to make out any detail on Jupiter at first but we decided to allow the mount and OTA to settle for about 5-10 seconds after slewing to its target. He started holding the eyepiece with his fingers and that seemed to help him. Didn't want to tell him not to because it was more important that he got the opportunity to see the heavens properly. I'm sure holding the eyepiece gently wouldn't make any difference, but putting too much resistance on the gearing as it tracks can't be good for it.

We're waiting to see how long a single pack of 8 batteries last before making a decision about a 12v battery. Only fair to give them a chance. So far they've worked better than I thought they would. If I don't get a battery I'll use a 5 Kg iron weight to add stability.

Still unsure why the OTA's primary mirror seems dusty considering it's meant to be brand new.

[TheQuietEarth]

Earlier I said I was going to save up for a new eyepiece in order to gain a wider FOV from the 127, but after doing lots of reading since then I think I might be better off spending at least £60-100+ on a new 1.25" diagonal to replace the stock Celestron one. It seems like one of the most important components in the whole setup and I think it might be the reason why I'm not getting the level of performance I thought I would have from the 12mm BST Explorer.

I'm going to continue reading up about which diagonals are best suited to the 127 SLT but so far I've looked at the ones for sale on FLO, such as the WO Dielectric Carbon Fibre diagonal. I'd be prepared to continue saving into June if buying something like a TeleVue Diagonal would produce a markedly improved image over the sub £100 diagonals. £150 would probably be my absolute limit given the price of the scope, and even then it would have to be significantly better than cheaper options.

As an aside, what happens if I remove the diagonal and insert an eyepiece directly into the rear of the scope? Will I be unable to achieve focus?

[faulksy]

as long as you get a dialectric diagonal you will not notice any difference gso or revalations are very good the more you pay the prittyer it will be. you can put your ep directly into the back of the scope and focus will be fine but it will be a long way from were it was, this will also give you a idea oh how bad or good your diagonal is. hope this helps

[knobby]

Ref the dusty mirror a few posts back, I think all mirrors... New or old look dusty when you shine a torch at them.

[TheQuietEarth]

knobby

Thanks for the reassurance. I've found similar comments on other forums re. Celestron scopes. It doesn't seem to be causing any issues anyway so I've stopped being concerned about it. The scope is well collimated and I can bring Saturn and Jupiter into focus with little difficulty. Made sure I was getting symmetrical doughnuts when I de-focused stars in both directions.

faulksy

Thanks for the advice. Just to ensure I'm understanding it correctly you're saying that I need to buy something other than a dielectric diagonal to notice any difference between it and the stock Celestron 90 degree diagonal? I thought the dielectric coating/surface would improve on the images I currently see.

Re. my earlier comment about the 12mm BST Explorer - I was wrong to say I'm not getting the level of performance I expected. It's better than the stock Celestron eyepieces and works perfectly provided that I allow the scope to cool to the ambient outdoor temp. and don't try to use it through the window of the room I'm storing the telescope in. I can't achieve focus on, say, Saturn if I try to see through the window.

Last night I made it so that I can swing the window wide open and point the scope in such a way that its path to the target isn't obstructed by optically inferior glass. Worked a treat although I was freezing! Filled a hot water bottle and kept it close while getting pin-sharp views of Saturn and her beautiful rings. It's also the first time that I've detected a hint of colour on Saturn.

I also managed to achieve great views of the surface of the moon, viewing the Schickard and Phocylides craters with great clarity. Used a very helpful Lunar Field Atlas (mirror image version) to work out which craters I was looking at. I need to keep a list of the lunar objects I find through my scope. Also need the same for Messier objects. I imagine that part of the enjoyment of this hobby is recording details of observations and then re-reading them years down the road. I remember watching Sir PM showing the camera his vast collection of data going back to, I think, the 1950s.

Anyway, I'm looking forward to tonight as the skies above Glasgow are pretty clear and the scope is currently outside cooling down.

[knobby]

Found this really useful

http://www.Google.co.uk/url?sa=t&source=web&cd=2&ved=0CDcQFjAB&url=http%3A%2F%2Fwww.1america.com%2Fastronomy%2Fpdf%2Fmessier_ref.pdf&ei=IdlZUZ-lIILXOaezgCg&usg=AFQjCNGkSoGR7PQyvfXuXn-0sa2vnEgRQg&sig2=Mt0vGaxae7z9okBI9wN_vQ

Saved it as a PDF on my phone

[TheQuietEarth]

Knobby

That's a great link. It's exactly what I was looking for and will be a great catalogue to keep and read over once it's completed... hopefully!

Tried to find Panstarrs last night but my line of sight to it was obstructed by a ghastly street light. Nevermind, if the weather is clear tonight I'll drive to a spot that'll allow me to get a more or less unobstructed view of the entire firmament.

[TheQuietEarth]

Had a difficult session last night. We decided to take the scope to a location that we thought would enable us to see DSO a little better than from our back garden in the suburbs of Glasgow. I should say that from my location I have no issue seeing the big solar system objects quite well (e.g. bands of gas on Jupiter, rings of Saturn, Titan, and a hint of colour from Saturn itself).

The place we went to is about ten miles outside Glasgow city centre and about five miles west of another major urban population. There's a link to it on Google maps. It also sits at about 1000ft ASL and high above Glasgow.

https://maps.google.co.uk/maps?q=bonnyton+moor+road,+eaglesham&hl=en&sll=55.742159,-4.318306&sspn=0.001291,0.004128&t=h&hnear=Bonnyton+Moor+Rd,+East+Renfrewshire+G76,+United+Kingdom&z=15

After setting up I was eager to see the difference in viewing of Messier objects like M42, M31 and M3 but was disappointed to see that there was no difference and I could hardly any definition through the 25mm EP. Oddly, Jupiter showed less detail at this location than it does from our garden, and it wasn't because we didn't allow the scope to cool as we'd had it outside for an hour before leaving for the site and after setting it up we left it for another 15 minutes before using it. It was absolutely freezing up there and the scope itself was painful to the touch with bare hands.

Still, I'm sure I'll get better views of these DSOs in Galloway Forest Park and/or with a much better diagonal.

Can anybody else with a 127 Mak share their experiences of observing DSOs so I can establish some realistic expectations in terms of its performance away from observing the solar system.

[heavensabove]

Can anybody else with a 127 Mak share their experiences of observing DSOs so I can establish some realistic expectations in terms of its performance away from observing the solar system.

I use the skymax 127 which is essentially the same scope and I absolutely love the thing , portable , sharp ,wonderful on planets and moon AND it is able to punch way above its weight when it comes to DSOs . But to get that level of performance from it you will HAVE to get yourself to a very dark site .

Glasgow like any major built up areas exhibits skyglows which will completelty wash out fainter objects .

Was galaxy hunting two nights ago and spotted about twenty fuzzies along the line between Phecda and Cor caroli alone !!!A few Messier but mostly NGCs , even managed to bag 4485 ( admittedly with averted vision only ) .

I am only 2 hours from you if you ever fancy a trip to the country side , there is no LP here .

So if I could give some advice , I would say don't go splashing cash on fancy eyepieces or diagonals etc.., just take the scope to a dark site and you'll be amazed what you can see ...I do almost all my observing with a 32mm Celestron Omni which was about 30 quid at the time and while I am not sure about the kind of diagonal that came with your scope , the one that was supplied with the skymax is plenty good enough .A wider field of view is only desirable for a handful of objects , the rest fits nicely in that eyepiece , I use a 12mm for planets and moon though.

I have observed with a friends 10" with fancy eyepieces under a pretty awful sky and wasn't impressed !!!

Also when observing planets keep in mind that the seeing on our part of the world is very changeable from night to night but mostly from hour to hour , this is especially relevant when observing planets and moon ( a moon filter is indeed one pice of kit you'll need as it can get blindingly bright ) , so a good view of jupiter one night will not guarantee the same view tomorrow or even in a couple of hours .

I find the best nights are early spring and autumn .When the seeing is bad I go galaxy hunting .

Hope this is helpful to you.

[TheQuietEarth]

Thanks for the advice and help, heavensabove.

It's good to know that the reason for the poor performance is because of the LP from Glasgow, East Kilbride and surrounding areas. Glad you've been able to see so many DSOs through your Skywatcher. I was looking at Cor Caroli last week from my garden and did take a detour but didn't really notice anything next to the twin stars. Just goes to show how much performance is influenced by cities and the light they throw off.

I've got the Celestron moon filter but haven't had the chance to use it yet. Looking forward to seeing the difference in views it produces, especially with the 12mm BST Explorer.

Yeah, I'd definitely be up for trying out a dark sky site in Ayrshire. I know parts of Ayrshire well as I lived in Kilmaurs and Kilmarnock as a kid and have friends and family in other parts. Will send a you a PM about that.

In the meantime I might try to take the scope into Whitelees Forest as it seems to be darker than most other local places according to the dark sky maps and layers I've seen on various websites and Google Earth. Part of the forest is open moor at high altitude and is reasonably flat over a distance, so that's where the largest windfarm in Europe is located. I used to go up there as a teenager (32 now) when there was only one wind turbine. Was a scary drive up there at night too, not like now as they have a visitor centre and all that.

Fortunately, from my garden I do get clear views of the major Solar System objects. I can see the gas bands on Jupiter clearly as well as Saturn's rings. My neighbour didn't believe me when I told him how capable the scope is so he's coming round this week if we get a clear night to see Jupiter for himself!

Thanks again for the advice.