Gfamily

In technical terms, there is a principle that the more detail there is in an image the less compression can be achieved - so if you order your images by file size, the largest files are possibly going to have finer levels of detail in the image. ETA This assumes that you have your images in a compressed format (for example Jpeg etc). Following on from this, a hint I recall from years back is to look at your images upside down - this removes the tendency of the brain to interpret the image, but allows the brain to assess the general shape and layout instead, which can lead to a more immediate response.

I'm not sure if this is any help, but I'm currently re-reading the Owen Gingerich book about his search for first and second editions of De revolutionibus In it, he mentions the Karlsruhe Virtual Katalog, which might be of use. https://kvk.bibliothek.kit.edu It's a great book by the way. Edit to add : it's called The Book Nobody Read. The title being derived from a statement made in Koestler's The Sleepwalkers

It was read out on Episode 120 June Part 1. What might be interesting is for you to use planetarium software (like Stellarium) to have a look at the region of the sky that the Hubble Space Telescope is currently looking at. So - start with https://spacetelescopelive.org/latest which will show you what HST is currently looking at If, when you look, it says "Hubble is acquiring a new target" - you can use twitter to see what it's been looking at recently on https://twitter.com/spacetelelive Each tweet has a link to an observation - an example is here https://spacetelescopelive.org/2022-06-08T11:18:57Z and the observation will be part of a research proposal. The research proposal will give a list of targets. However, as you can see, the thumbnail image includes the RA and Declination of the target, and you can bring this up on Stellarium (You might want to set the display to use "decimal degrees" rather than hhmmss (hit F2, go to the Tools tab and it can be selected there). You might find it fun to explore the same area of the sky as one of the 'Big' scopes.

Knowing our luck it would happen during the month of June and be between Taurus and Gemini (other months and unsuitable regions of the zodiacal constellations are available). One thing that was very personal was during the summer of 2021. I was out with my 'new' refractor looking at M22, while my wife was looking at Steve Tonkin's August Binocular Sky newsletter and very coincidentally also looking at M22. At the same time as we were both watching, a bright Perseid meteor flew about 1/3 degree from it , so easily viewed by both of us. The first time that either of us has seen a meteor through binoculars,

I saw Comet McNaught through an office window in Liverpool in December 2006 - It was not very long after Sunset, and the sky was still bright, but McNaught was clearly visible. I tried to phone my wife so that she could see it too - but wasn't able to get through, and it was the only cloudfree sunset that we had for about a week in both directions. For Southern Hemisphere observers, McNaught counted as a 'great comet'; I'm just pleased to be able to say I'd seen it 'before it was great'

This is a copy of the sequence suggested by Don Machholz. https://docs.google.com/spreadsheets/d/1lIKUywI95QJdrelI31vLJD4NhkJjgN5EZmeAP9k3ak8/edit?usp=drivesdk I derived it from this webpage for an attempt over the first moonless weekend this April https://spacetourismguide.com/messier-marathon/ I understand that it'll be updated for next year's date.

You might also enjoy the WorldWideTelescope website This gives you the opportunity to roam the sky, zoom in on areas and see what's worth looking at in your field of view. https://worldwidetelescope.org/webclient/ I suggest you start by selecting the Digitized Sky Survey (Color) and start exploring by clicking on the images at the bottom of the screen.

Hi Ash I suggest you have a look at the Crash Course Astronomy Videos on YouTube. These are presented by a great guy called Phil Plait - who calls himself the Bad Astronomer (because one of his first things was writing about Bad Astronomy in films, books and TV programmes) He's very good Anyhow - this should be a good place to start https://www.youtube.com/watch?v=sViAwfeMjV0&list=PL8dPuuaLjXtPAJr1ysd5yGIyiSFuh0mIL

The principle is that the split objective will produce two images, which move relative to each other as the micrometer screw is turned. When used as a heliometer, the two images of the sun start aligned and the micrometer moves them until the top edge of one image of the Sun lines up with the bottom edge of the other image. This allows the angular diameter of the Sun to be measured at different points in the Earth's orbit For Bessel's work, he used the heliometer to measure the angular difference between the fast moving 61Cygni and two reference stars several times over a period of a year or more. The telescope is turned so that the split images move along the line between the stars, so that one image of 61Cyg lines up with the other image of the reference star. The micrometer movement gives the angular distance between them. The two sets of distances produce a trace showing the average proper motion across the sky with a superimposed sinusoidal curve. The size of the curve gives a measure of the parallax. Here's a mini gif of some slides from a talk I gave to our Astro Society about Bessel's work

I took a handful of pupils to a residential centre on Anglesey where we did some imaging, so somewhere I have a slide showing Halley's comet.

Any rapid increase in floaters should be considered a red flag. I had a strange phenomenon of a mixture of bright flashes and short lived localised blackout areas in one eye - it came on very rapidly, just as I was getting out of the car one afternoon. I went straight to the local specialist eye hospital (where Mrs G had her detatched retina treated 5 years earlier) and got immediate triaged for assessment. It turns out that (fortunately) it was caused by the thickening vitreous humour pulling away from the retina, but without causing any permanent damage.

I initially thought that the docking would be timed as it passed over UK, but then I saw that the 23:10 scheduled for the docking was in UT rather than BST. As it happens, we had extensive cloud cover at the time - so only saw the ISS briefly as it passed the meridian. With binoculars we couldn't see any evidence of the Starliner module. ETA - got to say, great images

A new programme - although BBC4 has had its funding reduced that means it generally only shows archive material, this had special funding from a Norwegian charity called Kavli that meant that it cost the BBC practically nothing.

c.f.

According to the Wayback Machine, the cost of an 8" Edge HD (at FLO) was £1079 in April 2016 £1400 in Sept 2020 £1469 in Jan 2021 £1750 in April £1889 currently Given the significant problems with getting stock, vendors have to consider what margin they have too apply to maintain profitability when you might only have capacity for selling half the normal number of units.

A RDF on a hot shoe bracket can be invaluable for centering on the target. First align the RDF by using it to line up on a bright star. Take a 5 second image and work out how far the star is from the centre of the image Adjust the RDF so that it's lined up wth the centre of the image. Line up the RDF against the star again and confirm that it is properly at the centre of the image

One advantage of the L bracket is that it allows you to use the Polar Scope without removing the camera. In terms of 'how do you point the camera in at the target when using the L Bracket', the two degrees of movement available will always allow you to point the camera in any direction. However, you might consider mounting the ball head on the L Bracket as well to simplify that element of centering the target.

I can now admit that I'm officially an idiot Not only did I forget that I have a very nice 9mm X-Cel LX already (somehow mentally thought it was an 18mm - no idea why), but I just found the 'missing' 10mm Plossl in MrsG's Heritage 130P mini Dob.

Steinhardt should be looking for where to find the datapoints that would provide the disproof of his hypothesis. If they're there, he's done good science, if they're not there, it makes his hypothesis stronger. But I know l people aren't like that in real life, not after they've got their doctorates at any rate ! (I am joking of course)

No way would you be allowed to point it anywhere near any of the inner planets. Got to keep that sunshield aligned! And we have ESA/JAXA's BepiColombo on its way

I bought a second hand Altair Lightwave 72ED scope - lovely telescope, definitely my favourite at the moment. The only issue I have with it, is that the focus lock doesn't lock the focus when fully tightened. I assume that the knurled knob (A) has moved slightly on the thread that is supposed to move onto the rack and pinion of the focuser Can anyone advise which of the two grub screws ( B or C ) I should be looking to adjust ? Or is it something else? Cheers

I'm just wondering why you need to remove that part. I have to say I've only just started out with my first flattener, but on my 72mm scope it's simply a case of loosening the large knurled knobs and removing the 2" to 1"25 adapter. The 2" flattener then fits into the focuser. But as I say, I'm only just starting and I could be missing something.

It looks as though the link is still available via the wayback machine At this address - https://web.archive.org/web/20190223050207/https://download.microsoft.com/download/7/3/9/73918E0B-C146-40FA-B18C-EADF03FEC4BA/ICE-2.0.3-for-64-bit-Windows.msi (64 bit) https://web.archive.org/web/20190309221948/https://download.microsoft.com/download/A/7/8/A7804C73-ECDB-4459-BB3E-A7F13C4C5382/ICE-2.0.3-for-32-bit-Windows.msi (32 bit)

I was going to say that since that was released in 2014, there has been a change to the management of planes in UK airspace, which means that rather than the relatively narrow 'flightpaths' across UK shown in that visualisation have now been relaxed and that aircraft can now be found over a much wider area However, a quick look at the NATS website suggests that there is a current review of the use of airspace, that might (might) result in more precisely defined corridors. https://www.nats.aero/airspace/future/ But who knows? We're in NW England, and seemingly under one of the main high level flight paths, so I don't expect it to get any better

When Eyeaj Eyjak Eiyjak that volcano erupted in Iceland few years back it was noticeable how much clearer the skies were by early evening - far less of that high level milkiness that we saw at other times. And the shut-down of US Airspace after 9/11 led to measurable effects on the diurnal temperature changes over much of North America as I recall - there was much more efficient temperature loss at night. I believe I read somewhere that 'smart' scheduling of airline routes to fly at altitudes to minimise the production of contrails would do something like mitigate 25% of the Greenhouse gas effects and only take 1 or 2 % more fuel. I don't know the details - so don't quote me as an authority.