Barry Fitz-Gerald

On 25/04/2022 at 02:27, LukeSkywatcher said:

They just slightly changed trajectory in a curve and went their separate ways.

.............................by how much did they diverge from the original course, and how widely separated were they to begin with and at the end of your observation?   It has been mentioned here before, but when a satellite traverses a barren bit of sky without any bright background stars, it can appear to 'wobble' a bit as it travels, but this is just an optical illusion due to a lack of nearby reference points. Could this be a possible explanation or was the change in trajectory you observed more than could be explained by this?

7 hours ago, chiltonstar said:

.........................but I think the apparent movement doesn't match the wind direction.

Surface winds last night were easterly, but higher up (approx 30,000ft) I think they were westerlies - check out windy.com

Lots of birds about at night at the moment so it seems, had lots fly across the moon the other night, but they transit in far far less than a second, and with quite a few, you can almost discern shape and flapping wings.

Hmmmm, sounds like getting one of these for visual use only might be quite a subjective experience, might make a big difference, but might not depending on individual taste/perception. Bit like the CA in the SW Startravel 120, some find it a problem, I barely notice it as I avoid anything bright and shiny when I get it out.

Anyway, all the above comments are very useful, and I may give the Stellalyra one from FLO a punt as it looks like a GSO clone and reasonably priced.

I use an old photo bracket (see link below) and a simple kitchen cupboard handle attached to that. The bracket comes with 2 attachment wheels that fit directly into the photo thread of the tube rings. Heath Robinson but functional. The scope is an 80mm DSPro but the SW tube rings all seem to be standard thread.

https://www.amazon.co.uk/gp/product/B07CVWF35T/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

https://www.amazon.co.uk/gp/product/B01MR5U43D/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

If you do go for one you may need to factor in the cost a replacement dual speed focuser, because the one that comes with it is quite rubbish.

I fitted the SW Crayford to mine, and it is not a straight swap, the collar on the Crayford is a couple of mm's too wide and needed a bit of attention with an abrasive wheel on a drill to get it to fit the OTA.  Did not have a problem with a TS Dual Focuser however, that fit very well, but for some reason it stopped working after I dropped it on the floor.

Overall, the ST120 is a good grab and go telescope, but it is a wide field low power sweeper - and if you accept its limitations it is a super bit of kit.  Moon and planets are not targets for this telescope but on the brighter DSO's it performs very well, and the CA to me is not bothersome at all.  Some advise a Baader 495nm Longpass filter to counter the CA on Solar System objects for instance, but this makes everything looks like its smeared in mustard, so I do not bother with it, preferring the unfiltered view. I sometimes use it along side a Sky-Watcher Evostar 80ED DS-Pro, and on Solar System the 80mm is noticeably sharper (no surprise there) but on DSO's the ST120's extra 40mm  gives it a bit of an edge.

It is quite chunky as has already been stated, so needs a reasonable mount, a heavy duty photographic tripod like the Fotomate VT-680-222R just about manages to cope with the OTA and 1.25 diagonals and smaller EP's but if I use 2 inch accessories I mount it on a Sky Tee2.

With a Baader white light filter and a Baader Solar Continuum Filter it gives very pleasing Solar Views indeed.

So, overall a good little telescope, but with the recent price increases and the prospect of having to shell out extra for a Crayford which is really a must, it might be worth exploring other possibilities in the Achro/small Apo range.

Thanks for that info, That is very useful for me - if it is not providing a dramatic improvement I think I can live with the coma as well - especially as I do a lot of spur of the moment viewing and seldom go for tight doubles and so on.

Another factor that I never considered was my own deteriorating eyesight contributing to the less than pin point stars - I should have realized this much earlier but never factored it in.

Last night I experimented with a pair of new specs to correct for astigmatism and the difference was noticeable - less spiky stars and sharper focus - so it looks like I was the weak link in the optical train al along. So maybe a TeleVue Dioptrix might be a wiser investment instead.

Has anyone had experience of the GSO Coma Corrector used for visual in a SW 250 F4.7 NEWTONIAN or similar - or maybe even the Stella Lyra one offered by FLO which I guess is the same or similar?

Is a Coma Corrector worth shelling out for - or is the visual improvement marginal? 

I would get a Paracorr but I would have to sell the telescope to pay for it.

10 hours ago, PeterW said:

Yes, Porto, the end of  long series of slightly improve s models over the decades. Probably a deal heavier than modern fare and the eye relief is likely less too. I have some old Porto and they have wonderful wide views... though I have to glue my eyeballs to the eyepieces.

Yes - quite agree about the eye relief - pretty small, so the lenses do tend to steam up quite quickly at times which can be irritating, and the eye cups do not extend at all. They are just a shade over 1kg which puts them in the 'chunky' category, so not something to take on a long walk either.

As far as second hand binos go however I am always wary of the dreaded miss-collimation, not always easy to spot very minor poor alignment in daylight, but quite obvious when used for astronomy - so a vendor might describe them (in all good faith) as 'very good' but they might end up needing some maintenance which could cost as much as the binos themselves (been there, done it!). So second hand can be a bit of a lottery unless if they look pristine.

If I were after a single pair for astronomy, and did not want any risk of getting a lemon as far as quality goes I would probably end up going for some of the new offerings (like the SVBONY or VORTEX range offered by FLO) with modern optical coatings, lightweight chassis and so on, and with an option to return them if they did not fit!  Even the smaller modern 8x32 class binos can give older models with bigger objectives a run for their money.

You can get some excellent bino's now at extremely reasonable prices and they do seem to outperform older models..............in most cases.

After reading a review by Neil English on some SVBONY binos  - I got hold of a pair of 8x32 (£89) and 10x42's(£125) both great performers and super value for money - comparable with more expensive binos. But I find binos a bit like shoes - some fit, and some, despite the spec for some reason do not 'feel' right.  So, despite having these two and a couple of other premium binos, the ones that give me a bit of a thrill every time I use them is a battered pair of Swift Audubon 8.5x44's - part wrapped in waterproof tape where the original plastic type covering is torn and with dents in the metal body. The image however is bright, vibrant and sharp and the FOV massive - and for astro use they are excellent and can be held steady without effort despite their bulk. I would jump at the chance of a pair in better condition but I think used ones in good condition are not cheap. So do not write off the old duffers, there are some gems out there, but you would be best to try before you buy a used model.

In the middle of a field, miles from nowhere, I was sat in a reclining chair using some binos to scan the Milky Way in Cygnus. I leant back to view the zenith, at which point one of the bolts holding the chair together sheared and the thing collapsed backwards. I ended up with my head in the damp grass and my feet pointing towards Deneb and the chair angled back in excess of 45 degrees. I had the presence of mind to hold on to the binos as in the spur of the moment I thought physical injury and compressed vertebrae were preferable to damaged optical kit. I did a brief imitation of a dung beetle on it's back but managed to right myself using my elbows, as I needed my hands to hold on to my precious 10x56's. The binos were unharmed, but my dignity slightly dented. Luckily I managed to repair the chair.

8 hours ago, ItsmeMaw said:

I couldn't help but try and imagine the impact that caused the Mare, possibly being at a slight angle, to cause the high mountains to one side while the molten material flowed out on the opposite side.

You are correct, the current thinking is that the basin was formed by an oblique impact - as were many of the large basins and craters - here is a link to the Schultz and Crawford paper on the hypothesis:

https://www.semanticscholar.org/paper/Origin-and-implications-of-non-radial-Imbrium-on-Schultz-Crawford/dd40a9d0aa4853b3b6596bd08e53dbf2f682bca4

The paper was published in Nature in 2016.

Peter Schultz proposed the idea in 2001 using hypervelocity cratering experiments as evidence..............

https://www.lpi.usra.edu/meetings/lpsc2001/pdf/1900.pdf

The  mare filling came much later by the way and was not associated with the original impact event.

Rule No.1 for Newtonian Owners:

NEVER shine a light down the tube at the mirror - not that it will endanger your eye sight, just your peace of mind - as it will ALWAYS look dirty. Even if it isn't.

If it really bugs you however cleaning a mirror is very straightforwards - as noted above it is not a dark art, and there are plenty of on line video guides on how to do it - but to be honest your mirror looks fine and if it ain't broke don't fix it.

15 hours ago, Space Hopper said:

Worth pointing out that the TEC oil spaced design only has a few drops of oil between the lens elements, not half a pint or anything like that.

Thank heavens for that - I can dispense with the bucket on the observatory floor beneath the dew shield.

One possibility is the Astrozap Baader Solar Filters that FLO sell - they come mounted in a cell and made to fit a variety of telescopes up to 14 inch SCT's - I am sure they can advise on an appropriate size to fit your SW.  The largest they have listed for a newt is for  10" but maybe a SCT one will do the job. Alternatively you could make a mask to go over the front of your Newt and then use an A4 sized sheet of Baader AstroSolar Safety Film to create your own filter -  a lot cheaper but requires some basic Blue Peter DIY skills.

365 Astronomy also have a range of what look like custom made filters for SW newts - at what looks like a very reasonable price indeed (https://www.365astronomy.com/Solar-Filter-for-300mm-Newtonian-Telescopes.)

A Baader Solar Continuum Filter will really enhance the white light view as well - so if your budget stretches to that it would be a good investment.

With a white light solar filter and Solar Continuum Filter you will see a LOT of detail is the increasing number of sun spots, faculae and granulation under good seeing - and of course it changes every day. But if that is your dob in your icon - don't forget to put the cap's on the finder or you will end up with very frizzy hair.

Hello!....and Welcome,

I am sure you will get some replies in due course regarding your bino question.........I am sorry I cannot help with this as I do not have binos in that size range. But what I will say (not on the subject I know) is that if the SVBONY company ever produce something in that size range, 70 to 80mm they would be well worth considering, because I have tried their 8x32 and 10x42 SV202 ED range and found them to be amazing performers for a very low price. They were reviewed by Neil English I think, who was spot on with his assesment. Even though I would not normally use the smaller model for astro, they showed pin point stars in a nice wide field - the 42's were even better - I tried them agains a pair of 10x42 Leica Trinovids and they were pretty close!  Unfortunately the biggest apertures I can see from them is 50mm (and not in the SV202 range) which is below your size requirement.

Good luck with your search!

1 hour ago, JeremyS said:

But I don’t binoview that often as it’s a bit of a faff changing the binoviewers in and out, balancing etc .

Good point about balance...............I do use some of the Delos range for binoviewing - but with the diagonal, binoviewer and then a couple of long, heavy EP's you can end up with a bit of an unwieldy monster at the end of the focuser.  And if you have a diagonal with a screw in nose piece, you may have the embarrassing experience of the whole weighty contraption swiveling round with the EP's ending up facing down  or even, horror of horrors falling out!  Of course, this has never happened to me (!) Smaller EP's such as the Delie range or Tak's are much more sensible from the point of view of weight and length of the optical train. Also if you have a generously proportioned nose wider EP''s like the Delos can be a bother.......but if you have a hawk's beak for a schnozzle you should be OK.  Having said that the 17.3 Delos are spectacular as a BV pairing.

I use binoviewers on my refractors (80mm up to 140mm) when viewing solar system objects as this is where their strengh lies. You can pick up FAR more detail on the moon for instance due to the effect of 'binocular summation' and prolonged viewing is extremely relaxing compared to squinting one eyed. As noted above white light solar is also greatly enhanced with binoviewers, and the planets gain a more 3D apparance. The bino benefit is more complicated than just using both eyes - the effect of summation adds considerably to the experience.

On deep sky however I revert to mono as the binoviewers do reduce the brighntness of DSO's too much, unless you are viewing something bright like a globular or brighter planetary nebula, so the advantage of summation is generally lost in the overall dimming. Having said that I have not bino viewed through a large  reflector, so the extra light grasp may help - I know someone who bino-views DSO's with an 11inch SCT and that seems to work. If I do bino-view DSO's I use a pair of 24mm Panoptics and keep the mag low.

So - fully bino for Solar Systen and selectively for everyting else.

Of course, you will need a bigger eyepiece box..............................................

3 hours ago, Louis D said:

Just make a spot in the center of the donut with permanent ink or a tiny paint blob before cleaning in case that happens.  Soapy water won't generally remove either mark.

..................................wish I'd thought of that!

Your mirror looks fine as has been said, and if the images are good enough - then its good enough. Newtonian mirrors cause more unnecessary angst to newcommers than anything else and  I remember the horror at seeing my first mirror covered in moisture spots when it ended up with a coating of dew. But cleaning them by using tap water in a plastic bowl with detergent and fingertips followed by a rinse with distilled water works a treat - there are several guides on this forum or youtube to help you.  Comes out like new unless it is very badly corroded in the first place - you might end up with a couple of water spots which might look unsightly but they have zero effect on the view through the eyepiece. So eventually when it does need a spruce up dont be afraid to do it, just  be careful and prepare your workspace.  Try not to get the center spot too wet if you do ever go down the cleaning rabbit hole by the way - dont want it comming adrift as re-spotting a mirror is a pain - doable but you will always wonder how accurately placed the new spot is. Best advice with a newtonian is spend little time looking at it and most time looking through it.

As far as fingertips to clean the mirror surface goes -  I might be reluctant to sub contract the cleaning out to a blacksmith or bricklayer or someone who's hands are so hard an calloused through hard labour that they have fingertips like emery paper..............fortunately I am workshy so have no problem in that department.

Are they Swift clones by any chance? Look remarkably like the Audubon series......

Thanks Rich, On the basis of everything so far I think the best candidate is a sattelite combined with viewing through some unstable layers of air which caused an apparent deviation to a straight trajectory when viewed from your location. Never seen this behavious myself though, and not sure if it fits 100% with your observations, but it would probably be the least unlikely explanation.  Might have to file it in the 'unresolved' box and keep an open mind! 

I bought a pair of these binos from a Hospice shop recently for £40. They have had a hard life - maybe not as hard as yours, but still a few dinks to the end plates and scuffed barrels. Looking down the tubes the objectives are dirty  (how the dirt got in there heaven knows) and there are black particles and a bit of fungus on the prisms. I guess the particles are from paint dislodged off the inside of the tubes. Despite all this the images through them are sharp and collimation is spot on - you can see the particles on the prisms as fuzzy blobs if you view a bright background, but looking at birds down the end of the garden they are very good. I got a quote from a binocular repair service that I have used before and who are top notch (in Norfolk) of £40 for a clean and service, which given the optical performance in a cruddy state would probably we a worth while investment. Forty years ago these binos were almost top of the range and compared with the East German Carl Zeiss quite favourably. Maybe a bino engineer could produce one functionong bino by cannibalising the one in poorest condition?

Oh! Sorry to hear that...........hope things are patched up now!

Comment was for the OP sorry for confusion, but any info that would add to the OP's quest for an answer would probably be relevant.

52 minutes ago, Starwatcher2001 said:

Police helicopter following some person of ill repute

Hi Starwatcher 2001,

Police helicopters tend to stick to 2000ft or lower in transit to an incident and may go much lower when they are engaged on a job - at those heights they are very noisy. The searchlights (called a nitesun) are only effective in the hover (even more noisy) and below 500 - 1000ft and form a very prominent beam reaching from the helicopter down to the ground - bit like a laser but much much wider brilliant white beam. At those heights their navigation and position lights would also be conspicuous.