Tomjo59

Maybe an equatorial tracking platform?

I have one made by WatchHouse (not sure if they exist anymore), which I used with a Dobsonian mounted Newt.

Or maybe make your own:

Like many on here, I have fond memories of S@N with SPM; I’m even old enough to remember a few of the black and white ones.

I do wonder how much of the regard for it is pure nostalgia though. Surely S@N is suffering from the same problem as many scheduled broadcast programs these days - we now have so many other channels open to us to get our astronomy ‘fix’.  Look how many enthusiasts have their own channels on YouTube now, in addition to actual documentaries.

It could be argued that traditional sheduled programming is a dying medium these days, and I won’t get into the debate over the TV licence fee!!

A random musing for a Sunday evening.

The lenses in my spectacles are plastic. They correct my short-sightedness and astigmatism perfectly.

Has anybody or any company tried creating lenses for serious astronomical use using plastic, the equivalent of apochromatics, for instance?

Obviously, I’m not talking about the lenses in cheapo refractors from department stores.

I assume there are good technical reasons why this has not already been done, rather than using exotic and expensive glass; I would just be interested to know the reasons.

Only visual for me so far, but last night, on Perseid watch, had a good, long look at Jupiter, through the 8" Newt and the detail visible was excellent - really wished I could have done some imaging then!

Looks like SpaceX might have got the message:

https://astronomynow.com/2020/05/05/spacex-to-debut-satellite-dimming-sunshade-on-next-starlink-launch/

Not much they can do about those already launched, of course...

Very pretty indeed.

Looks just like my dewshield (also on an 8” Dob). Made from an old foam rubber excercise mat.

it definitely helps keep extraneous light out, and my secondary doesn’t dew up any more

Brilliant picture; did you take that through the Dob?

(Only joking!)

Brilliant image, great resolution.

Congratulations!

Nice clear images Stephen.

Sky and Telescope magazine have two very good free apps you can download, one for Jupiter and one for Saturn, showing the positions of the moons.

It would be a pity indeed if visual observing declined, but as other posters have pointed out, it may be due to circumstances, particularly light pollution.

I used to occasionally attend a get together of amateurs for a night’s observing here in the New Forest. At first, it used to be almost all visual, with people chatting, and wandering around looking through each other’s scopes; it was very ‘social’. As time went on though, more and more would bring along imaging kit, and most of them would spend the evening hunched over laptops, and not engaging very much with ‘non-imagers’.

a pity, I thought.

Located Neptune without too much trouble over the last three nights, though the seeing here in South Wiltshire was poor last night compared to the previous two; weather is definitely on the change.

A question I would like to ask though, is has anybody on here managed to glimpse Triton on anything smaller than a 10” reflector, or equivalent?  There seems to be a view that a 10” is the minimum required to achieve this, so am I wasting my time trying with an 8” Newt?

Bet this produced a meteorite. Probably at the bottom of the English Channel now though!

Starting to (re)appreciate just how pleasurable to use a good pair of binoculars are.

So hoping to buy a pair of  Helios LightQuest-HR 80mm Binoculars soon, with a pistol-grip tripod head. This following the advice given on Steve Tonkin’s excellent Binocular Sky website.

Lovely looking ‘scope. Hope you enjoy using it!

That ‘wheelbarrow’ arrangement for moving it around is a nifty idea.

Exceptionally clear here in south Wiltshire last night.

Grabbed a met office map for midnight.

I believe this situation, between two anticyclones and two low pressure areas is called a ‘col’.

I don’t know if this is generally regarded as favourable for good observing conditions?

For the astrophysics of stars specifically, I recommend ‘Starlight’ by Keith Robinson.  This is published by Springer, and is in the ‘Patrick Moore’s Practical Astronomy Series’.

An excellent introduction to stellar physics, with clear explanations.

10 hours ago, tomato said:

I must be turning into a grumpy old man because nowadays most TV documentaries do seem to make 10 minutes of footage last an hour by recycling the same content. I remember the Horizon and Equinox programmes in the 80’s and 90’s being so superior, maybe it’s the passage of time.

I think it’s called ‘dumbing down’.

Seems to afflict most of the media these days. Not sure there are any real journalists, who actually investigate stories anymore. They seem to cut and paste each others opinions.

Has anybody noticed that the forecast on the BBC Weather site changes virtually by the hour?

Almost as if they stick their heads out of the window, and think ‘we got it wrong, better change the forecast quick’.

Very unreliable beyond the current day.

21 hours ago, andrew s said:

If you Google " early solar system simulations" you can find several you tube clips and some interesting papers on this topic.

Regards Andrew 

Yes, I’ve seen those, and theories such as the ‘Grand Tack’ seem very speculative (some might even say contrived), and are not without their problems (see https://en.m.wikipedia.org/wiki/Grand_tack_hypothesis, for example).

I suppose that is how science progresses though. I suspect that the uncertainty and complexity of the theory is why Cox didn’t really mention the mechanism by which the migrations took place.

On 10/06/2019 at 22:24, niallk said:

Yes as far as i understand, it is a temporary installation.  Its a large suspended 3D globe.

London is a great place + the staff everywhere we went were so friendly and helpful: hotel/train & subway stations/restaurants/museums... could teach the Irish a lot about hospitality!!

Looks fantastic.

They should make it permanent, if it is only temporary.

4 minutes ago, maw lod qan said:

Did it migrate in a regular shaped orbit around the sun? Or in an elipitcal shaped orbit, similar to a comet?

The forces either way would be incredible for it to eventually end up so distant from the sun in the orbit it's in now.

A fair question.

I can’t imagine it would have had a ‘comet-like’ orbit, and I assume that a change of a more normal elliptical orbit would have to be related to a change in the overall angular momentum of the solar system, especially the relation between the Sun and Jupiter.

I’ve watched the latest program of Prof Cox’s ‘The Planets’ series, about Jupiter.

He states that computer models of the solar system’s formation  indicate that Jupiter migrated towards the inner solar system quite early in its history, explaining several ‘odd’ features, such as the small size of Mars, lack of ‘Super Earth’s’ etc. Jupiter then migrated outwards again, apparently.

However, it didn’t seem clear from his description exactly WHY Jupiter should have performed these migrations.

Did I miss something?

Many, many times on here, I’ve seen recommendations for ‘Making Every Photon Count’ by Steve Richards.

As getting into astrophotography is something I have considered for a long time, as a natural extension of my lifelong visual pursuits, I bought a copy. It is indeed an excellent book, and I’m very glad that I spent the twenty quid on it, but not for the reasons you might think. Having read it, I decided that I would have neither the time or the patience required for acquiring and processing (especially the latter) deep sky images. Consequently, it may well be that spending twenty pounds now has saved me vastly more in the future!

The book only deals with  deep sky imaging, and it may be that I still have a go with webcam imaging of solar system subjects, which looks a lot less faff.

Just my opinion, of course, and I have the greatest admiration for those who do take the time and trouble to produce the breathtaking deep sky images we all enjoy seeing.

Just my two-pennyworth.

The square solar filter was made out of strips of upvc right-angled moulding, and two layers of thick white cardboard with Baader Planetarium AstroSolar Safety Film ND 5.0.  The whole is secured to the OTA with duct tape for security.

The off-axis circular aperture is 90 mm in diameter.

Not as sophisticated (and certainly not as expensive) as some of the kit on here, but it serves my purposes!

I find that the best magnification to use is  130x.  Any more than that and the 'floaters' in my eyeballs become too obtrusive when looking at the Sun's disk!