Cosmic Geoff

I wanted to observe some asteroids as I had not done it for a while, and the easiest way to spot and identify them seemed to be to use my EEVA rig.  Identifying an asteroid visually can be difficult unless one is sure to look in the right place and has a star chart that matches the eyepiece field size and the magnitudes of the visible objects. And the image reversal in a star diagonal makes it much more difficult.

On 18 Feb I imaged four asteroids using: 102mm f5 achro, ASI224MC camera and SLT GoTo mount.  Vesta, Melpomene, Echo and Amphitrite.  I plate-solved the images the next day, to find that I had got Melpomene and Echo but missed the other two.

On 22 Feb I imaged Vesta, Amphritite, Eunomia and Irene, using live-stacking, with 102mm f5 achro, ASI224MC camera and EQ5 Synacan GoTo mount.  I plate-solved the images at the telescope, to find that I had three of them but needed to change the aim and repeat to get Irene.   With this setup, a mag 9 to mag 10 asteroid shows up clearly on the laptop screen as a bright dot with a 5 second exposure.

Platesolver 2 highlights any non-catalog items in the field and one can check the co-ordinates of any object in the solved field. The image reversal in a star diagonal does not trouble it at all.

I have had the EQ5 Synscan upgrade for around 10 months but this is the first time I have managed to do anything really useful with it.

It would be interesting to observe asteroid movement over a period of time but with the current rotten weather it is good to have a method that only requires one image or stack to positively identify the asteroid.

One of the images appeared to have two bright non-catalog objects on it, which is something I may investigate later.

I don't have a 2" diagonal. I could never see the point.  You also need a 2" visual back, and it adds up to a significant expense just so you can get a somewhat wider FOV with a low-power eyepiece.   You can go to about 32mm focal length in the 1.25" format.

The easiest way to identify asteroids in a star field is to image it and then plate-solve the image.   If you are able to plate-solve an EVAA image at the telescope, you can also check that you are aiming at the right field.

You will get some conflicting opinions, as some people clearly could not get along with it.

I have it installed on a C8 SE as part of a quick-deploy setup.  I can carry the whole assemblage out in one piece and have it working in a few minutes, and Starsense works well in this role.  On the other hand I have not found it to be more accurate than a 2-star auto align with the original handset.  I have also found it can be defeated by an over-bright sky in conditions when a 2-star or planet align could still be attempted.  But it can give a successful align even through patchy cloud cover.

41 minutes ago, CosmicRayResearcher said:

Follow up question on my part here. In truth we need something like < 1 degree error on zenith. Smaller numbers are nice, but since we hope to make many measurements at different places in a single night, an easy and fast setup has an advantage over higher pointing accuracies.

My Starsense camera system + alt-az GoTo mount regularly achieves an accuracy of better than +/- 15 minutes of arc without reference to the telescope.

By the way, I am not sure what exactly you intend to do with the laser, but aviation and police authorities in many countries take a very negative view of lasers directed at the sky.

I looked up the telescope online and found the instruction manual.  (just search on the telescope name). As Ricochet says, it would be a great help if you could post photographs. 

Assuming you have the focuser, you will need to refit it.  From your post it appears that you do not have any eyepieces.  It is not clear what the diameter of the eyepiece is (most modern telscopes take 1.25" or 2" diameter eyepices, but older or budget types could take 0.965"). 

I doubt that you will be able to find specific spare parts for this scope, but a cheap generic 1.25" diameter 25mm focal length Plossl eyepiece should cost  from $10 or so (and a good quality eyepiece could be $50 or more - astronomy is not a cheap hobby).

Do you have the mount that should come with it? If not, you will have to acquire or make one.

I am not sure what you mean by 'self levelling'.  It is however possible to attach a plate-solving camera accessory to some alt-azimuth GoTo mounts so that the mount will align itself to the stars automatically, without skilled human intervention.

As for battery power, almost all GoTo mounts require +12v DC power, which can be supplied from a +12v battery or derived from a mains powered supply unit.

I don't think there are many heavy duty alt-azimuth GoTo mounts in the price range you indicate.  One alt-az/Eq mount comes to mind, but nearly all the heavy duty mounts are of the equatorial type.

18 hours ago, Darran said:

should this be enough to get me going in the right direction?

That depends on you. The key to successful asteroid hunting is 1) look in the right place. 2) be able to 'spot the difference' and determine which white speck is the extra one (the asteroid).  A GoTo mount will be a major help.  My scopes have star diagonals whcih are a distinct disadvantage as they erect the image but leave it flipped l/R.  If  you have the budget and are sufficiently interested, you could invest in a correct-image prism diagonal.

47 minutes ago, NorfolkGazer said:

the Celestron Starpointer Pro

I bought one of these. It would not work at all till I inserted a piece of foil to complete the battery circuit, rather than send it back.  The display is too bright even on the minimum setting.  It does come with several alternate mountings.  I eventually installed it as a second finder for coarse finding of GoTo alignment stars.

Not recommended.

I never found the effects of cooling very noticeable with my 127mm Mak.  Maybe the setup time was enough to cool it, or maybe I just have bad eyesight. 🙂  If necessary, you could put a Mak outside a bit earlier to cool down, or look at the less critical targets first.

But if you really want a bargain priced Evostar 102 you might as well go for it. If it is anything like the Startravel 102, it will be a handsome and well-made 'scope.

This outfit is in stock? Not necessarily a good sign, in the current situation. 🙂

I used to have a 203mm f5 Newtonian on an EQ-5 manual mount. I thought the combination was horrible and soon abandoned it.  This outfit is not well suited to beginning deep space astrophotography.  The typical deep space imaging outfit is a small high-quality refractor on a heavy GoTo equatorial mount.

If you are interested in deep space astrophotography, you should obtain and read "Making Every Photon Count" by Steve Richards, available from FLO. It could save you from making expensive purchasing errors.

47 minutes ago, Pete-Tebbs said:

However I was offered this reflector telescope, stand and mount with various eye pieces some has threads inside and out, a barlow don't seem to have any lenses. it seems abit of a mishmash. The spotter scope only has a lense at one end with crosshairs, the mount seems to also include some sort of viewing scope. All this was offered for £50 I had to make a quick decision, but thought is was still a good deal to start with and add too, thought it was a good start. After some quick research before buying. Unfortunately on the outskirts of Lincolnshire all we have had is 98% cloud cover with rain for over a week. So haven't had a chance to even have a go yet.

I would like to finally add a Raspberry pi camera module for photography.

Looks like you have a bargain! It should be a good outfit for visual use. The Barlow, if complete, will have a lens at one end only.  The 'spotter scope' (finder) may be incomplete. The 'viewing scope' in the mount is intended for polar alignment.

I am not sure what you intend with the Raspberry Pi module.  This scope is not ideal for astrophotography.  The optical tube might serve, but you may have trouble getting a camera to focus.  Except for the very shortest of exposures (Moon?), you would need a motor drive on the RA axis.

If you have not yet encountered it, get and read "Making Every Photon Count" by Steve Richards (available from FLO), and if you are still interested in trying deep space astrophotography after reading this, add up the total cost of his kit...

20 minutes ago, Adaaam75 said:

but the CFM still doesn't recognise the equipment

It will only recognise the equipment if the comms are working, and achieving that may not be as simple as plugging in a USB cable.  It certainly wasn't as simple with the earlier serial port version, where you had to find a USB to serial adapter, buy a cable, install a driver and assign a serial port.

Or if it finds stars, you could just leave well alone.  People seem to assume they have to install these updates, but it only makes sense if they solve a security issue (totally not relevant with astro mounts) or you have it in black and white that the update fixes a problem you are experiencing.  In the case of Starsense, it seems that the updates do fix some issue with EQ mounts.

37 minutes ago, Adaaam75 said:

Well that will help me understand it properly. Could you tell me what point I need to press Align instead of Enter please?

Page 12 of instructions: First Time Setup: Calibrate Centre. After performing paragraph 2. you have to press ALIGN, then carry on.

I don't know why you are having trouble with the software update, but you need to get the calibration problem sorted first. 

IIRC you have to install Java or some such software before the CFM will work.  Also remember that if you really must give yourself grief updating the mount software, you can put the original handset back on the mount to remove the Starsense from the equation.  There used to be a separate utility (whose name or acronym escapes me at present) for testing and updating the mounts.  

In the case of the SE mounts, the mount software rarely gets updates and generally will not require updating.

There appears to be a fault with the Starsense instructions in the section describing how to calibrate the camera electronically with the telescope.  I posted about this on the forum previously.  There is a point at which you should press Align instead of Enter.

You do have to enter the date and time each time you power up the Starsense. 😦

The system may require a software update, but before that, get it to work properly as-is, and read the small print of what the updates actually do before you try any update.

A plain EQ mount if used visually requires adjustment about just one axis to keep an object in the eyepiece field (assuming it is polar aligned).  You can in most cases fit a RA motor for hands-off tracking. Some might consider this an advantage, while others prefer the simplicity and ease of aiming of an alt-azimuth mount.

Moving to GoTo mounts, even an alt-azimuth type will track. There is no need for an EQ mount here unless you intend long exposure astrophotography.

I am not sure what exactly you mean by a 'red zone.'  Where I live, the skies are said to be Bortle 6,  and trying to look for deep sky objects (galaxies) is not a rewarding exercise.  I was able to see far more galaxies when I took my C8 SE to rural Devon.  So, if your objective is to view galaxies and you live in a city, it just isn't going to work.

The suggestion that you invest in EVAA has merit.  I experimented with this here, and was astonished to find that on imaging a galaxy I'd also seen in Devon I could make out another fainter galaxy in the image that was less visible in the Devon skies where I used a telescope twice the aperture.

If you are confined to observing from a city, you should concentrate on observing objects like double stars, globular clusters, planetary nebulae, open clusters, and planets, as their high surface brightness will cut through the murk.  For this a long focal ratio telescope such as a traditional achro refractor, Maksutov or SCT will serve better than a short focal ratio Newtonian. 

Likewise you should invest in a GoTO mount, not a Dob mount, as 'star hopping' will be difficult when fainter stars are hidden by light pollution.  With GoTo you need at minimum to be able to see and identify a couple of brighter stars, and the electronics will do the rest of the work of finding faint objects.

I would also point out that when seen visually, galaxies do not look anything like the photographs. All you can typically see is a faint grey smudge representing the bright central nucleus.

The Evostar does not seem to offer much advantage over the Newtonian - similar weight, length and focal length.

A ST80 will be very portable, but maybe a bit small? 

I have found a ST102 to be a useful instrument. It can be safely carried with one hand, and can be used for widefield, comet hunting, and EEVA style imaging with a planetary camera, and it has a 2" focuser, so you can attach a DSLR to it.

It reminds me of working some years ago for a company that did warrantry repairs for a well-known manufacturer of home/small office printers.  A few customers imported USA model printers to the UK and wondered why they went pop.  Unfortunately for them, the USA models were fitted with 120 volt power supply modules, while the UK mains is 240v.  Just to complicate matters, worldwide power supplies that will work on either 120v or 240v without adjustment do exist.  But you can't assume that you have one without reading the small print.

Without commenting directly on the original poster's experience, this should be an object lesson in being very careful when you pick up a power supply and think of plugging it into your mount.  It could be the wrong voltage, or the polarity could be wrong, or it may not supply enough current, or the plug could be not quite the correct fit, or it could be a shoddily made item that self-destructs and takes your mount electronics with it.

If you are not skilled in these matters, play safe and buy a power pack that is specifically sold for powering astro mounts.

I never heard of a laptop charger that did not deliver 19 volts. 😲

32 minutes ago, dweller25 said:

refractors are also less affected than a C8 if the seeing is poor - which it often is

A 127mm (5") Maksutov will also challenge a 8" SCT (including for planetary imaging) when the seeing is poor - and it is a lot more compact, lighter and cheaper than a 5" Apo. 

11 hours ago, Anser said:

 Most of my viewing will be to the southern skies so an EQ mount would be difficult as I can rarely see Polaris.  

If you can find a fixed position for an EQ mount and mark the positions of the tripod feet, you only need to provide an alignment accurate enough for visual use and do it once.

I would suggest that you only spend the full 1500 pound budget if you are sure about what you want and what you intend to do with it.  If this is not the case, I recommend you get a smaller and simpler outfit and use it tikk you can decide what to buy next.

The C8 SE is mentioned. This is a good outfit for visual use and with a few accessories (eyepieces, dew shield, power tank) will fill out your budget.  The outfit is portable - you can pick up and carry outside the whole assembly, and it breaks down into three sections if you want ti take it on holiday to a dark site.  However, even though the C8 SE costs a wad of money, the mount is only suitable for visual use.  You can use it for planetary imaging, but the wobble and backlash will prove trying.  If you want to do any planetary imaging at any time, you'd want to spend even more money on a C8 variant with a better and more solid mount.

The new Classic Cassegrains look like an interesting option if you want a planetary scope. Other possible OTAs that might catch your fancy are a f8 Newtonian, or a !80mm Sky-watcher Mak on a suitable mount.

Au usual, various people recommend you buy a Dob.  I would urge you instead to consider a GoTo outfit if you can afford it, which it seems you can. A proper mount is as important as the scope itself, and with a good GoTo mount you can do so much more, and spend your time looking at objects rather than for them.

Should you be told that GoTo are hard to use, I would say that the ease of use of GoTo systems varies greatly.  The Nexstar system is easy to learn, and adding GPS or a Starsense reduces the effort further.

I was inspired by LeeHore's effort on 21 Jan to see what my 127mm Mak would do. I usually image with a 203mm SCT.

The Mars image was taken with a 127mm Celestron Mak on the SLT mount and a wood tripod, with ASI224MC camera (no ADC) and with & without a x2 Barlow.  For once, the Barlowed images came out better than the direct image. I was able to compare them directly in Photoshop after digitally enlarging the smaller image, the smaller image appearing distinctly pixellated.  Best 20% of 5000 frame video, processed with Registax6.  The image shows Mare Cimmerium etc. Angular size 8.4"

The Moon image was one of a number of images taken with the ASI224MC, full chip.  Best 25% of 1000 frames, processed with Registax6.