Nik271

The quality graph you have is typical of poor seeing conditions. I think your image is fine for below average seeing. It is very rare that you get good seeing at the current altitute of Jupiter. Also focusing is much harder when seeing is poor. It may be easier to focus first on a brigh star near the zenith, e.g Deneb at around 7 or 8pm in the evening and then aim for Jupiter. The small Maks have very little mirror flop (at least mine does not have any that I can notice), so your focus should stay good after that.

I think its like pitting a Mini vs an Audi A8. The Mini is cute and nimble in the city but on the motorway the big engine of the Audi will blow it away. 11 inches vs 4 inches as an awful lot of aperture to compensate. The C11 creates such a large image in the focal plane that you will see a lot more detail in almost any condition. I think a fairer comparison could be between the Tak and a C6, perhaps even a C8. There comes a point where the aperture will win.

Indeed. Some of these moons only show up with averted vision and disappear when you stare at them too hard.

Very nice report, I enjoyed reading it. To answer your question: a 10 inch dob will collect about 50% more light than an 8 inch. The formula is simple take the square of the ratio of the diameters, so (10/8)^2= 100/64= 1. 5625. This will be noticeable if using the same magnification. You should be able to see all the moons of Saturn of magnitude 11 or above, provided they are not too close to the planet: Rhea, Dione, Tethys, Titan of course, and Iapetus. Iapetus is quite far from Saturn so easy to confuse with a star.

Bahtinov masks are not very expenisve you can make one yourself from cardboard. I never rely on the autofocus of my camera (Canon 250D) for astrophotography. First manually focus on a bright star using the dispaly at x5 or x10 magnification. At such focal lengths (1600mm and above) the atmosphere is the main limiting factor. So you need to take many shots and stack the lucky ones. Keep the shutter speed between 1/100 and at most 1/500, if you go any slower than 1/100 the air turbulence starts to blur all photos; faster than 1/500 and noise will become a problem. Also with 1/100 second exposures you don't need a star tracker yet

Superb, just look at these tiny craterlets in the sea of Nectar!

These are from this morning's Moon at about 6am. The seeing seemed good, so I took 5 minutes of 4k video panning across the terminator and stacked frames with several areas of interest. The initial results looked too harsh, so I used the 1.5 drizzle for a softer look which seems to look better on my screen. Skymax 127 with Canon 250D in prime focus. Sea of Tranquility. Theophilus trio and Rupes Altai Sea of Serenity:

Or if you can't make it, fake it. This one from 1978 is surprisingly good.

Space X is not the first to achieve vertical rocket landing: https://en.wikipedia.org/wiki/McDonnell_Douglas_DC-X This technology is not new, of course making is commercially viable is a first for Space X. You are completely correct that the technology we currently possess allows us in theory to go to Mars, land people and come back, with several preparation stages. It just involves such an enormous cost to the economy that nobody has managed to push it through. Also the success of the robotic missions after Apollo showed that as far as scientific data collection is concerned there is no need for human space flight at this stage.

I think the cheapest and quickest way is to go outside during Mars opposition and concentrate very hard while staring at it, according to certain Mr. John Carter. He came back several times and wrote about it in the 1920s.

Or build a tunnel to Mars. At least the vacuum is free this time

Yeah, fuel the Starship in Earth orbit and send it on a one way trip to Mars with a load of fee-paying passengers and Musk as captain, this certainly has my vote

I voted for after 2038. There are huge challenges of a 3+ month long flight carrying many tons of stuff under pressure and temperature we humans require. Even current lightweight robotic missions wait for an opposition to reach Mars with enough fuel for landing. Simple calculations shows that for a return filght first we need to deposit a lot of material and fuel in orbit at Mars, then do a practice run before the real thing. I don't think there are enough oppositions between now and 2038 to make this possible: I have not seen yet a serious technical prosposal with costing and finance backing ready to go, so forget about even starting before the next two oppositions. Space X is not offering any really new technology to the picture, a fact which may disappoint some of Mr. Musk's fans out there. But I think eventually we will get to Mars and in fact should get there if we don't destroy our civilisation this century.

The low clouds/fog finally cleared up this moring and I had a pleasant 30 minute session watching the sun with a coffee in the garden. There are two prominent sunspot groups with lots of sunspots and faculae near the limb. The seeing is not great, I stayed at x80 for a nice view of the whole disc. Tried a light green filter and it improved on the contrast. I guess a solar continuum filter is my next purchase. Cheers, Nik

There are multiple reasons why x600 is not gong to give a pleasant view in 130SLT. The atmosphere limitation mentioned above is one very important reason. Another is that with 130mm aperture the resolving power of the telescope is about 0.9 arcsecond, so magnifying the image beyond x300 is just going to make it blurier no matter what. At such extereme magnifications the mount is also a weak link, any slight move even someone walking nearby is going to create vibrations which magnified 300 times will make the viewing experience difficult. I would stay at x200 and below so a 3 or 4 mm eyepeice should be the maximum. Or a 10mm EP used with 3x barlow.

If you find the Moon too bright, then get this inexpensive Moon filter: https://www.firstlightoptics.com/moon-neutral-density-filters/astro-essentials-nd96-0-9-1-25-moon-filter.html For a bit more money you can get the variable polarising filter on the same section https://www.firstlightoptics.com/moon-neutral-density-filters/astro-essentials-variable-polarising-moon-filter.html , with that one you can adjust how much light to block.

Lovely image! Just shows what a 80mm can do. Io seems to have turned quite a bit blue, or is it dispersion?

Very unusual view of Vallis Schroteri right now on the terminator. The mountains cast long shadows over the rille and it looks very different from when the sun is higher. Take a look if you can. This is the simulated view from NASA but imho the real time view from a scope is even better!

Caph (Beta Cas) is the westernmost star of the 'W 'of Cassiopeia and rises high in the sky in autumn and winter. As the full moon approaches I was looking for some double star challenges and with the help of some excellent books I made this list. All of them except the last should be doable in theory with a good scope of 4 inches of aperture or above. I have seen some of them with a 5 inch Mak, of course larger aperture will make it easier. Here is a star chart: 1: Caph itself. It's an optical double with very wide separation, more than 1' (minute!) west, however the primary is 2.3 and the secondary is 12.4. You need good transparency if you have small aperture. Southwest of Caph are two 6-th magnitide stars, and they are both challenging doubles: STF 3057 and STF 3062 2: STF 3057 (mag 6.7 and 9.3 separattion 3.9'') has a dim secondary which makes it a challenge. 3: STF 3062 (mag 6.4 and 7.3 separation 1.5'') is a close double, on the limits of a 4inch aperture. This is a physical double with a period of 106 years. the pair is sarting to close again and by 2050 will be only .5'' apart 4: Sigma Cas (mag 5 and 7.2, separation 3''). Again the challenge for this one is the dim secondary. 5: 6 Cas (mag 5.6 and 8, separation 1.5'') This one is the most challenging I've seen myself from this list. It's both close and with magnitude difference, reminds me of Zeta Herc. I used a 7 inch Mak for the split. 6: 9 Cas (mag 5.9 and 12.6, separation 82'') This one is very similar to Caph. Optical double of course. Every list has to have one impossible/improbable challenge so here it is. Not for the 4 inch aperture, more likley for a 20 incher on top of a mountain and the observer with the eyes of an eagle. 7: Bu 1224 (mag 6.7 and 13.7 separation 3.5''). One of Burnham's discoveries. Never seen it myself. I had a look last night, no chance. Clear skies! Nik

Yes, it's pretty close to the maximal elongation, which is at the end of October I think. Because it's far away from the Sun you can also find and look at it in the afternoon even before sunset. Binoculars show it easily.

The planets are low in the sky this year and the atmosphere rarely allows magnification much higher than x100. I assume you have the 102mm Startravel. If it came with the erect image diagonal my advice is to get an ordinary mirror diagonal as the errcting prism does not work very well with small bright objects like Jupiter. You could get a 6mm eyepiece which you can then barlow for x166 magnification but the scope will be at its limits.

I just came back from a good session with my Skymax 180. The seeing was decent and managed to push the magnification to x220 on Jupiter. Ganymede is obvious as a sharp dark disc slowly moving along the equator. Many bands on Jupter are visible. Now fog is rising again and I decided to pack up. My best seeing in autumn and winter seems to be just before the fog arrives

Well done on M33 an M110! I'm always thrilled to see them myself, becuase it happens very rarely in perfect conditions. M1 is much easier compared to M33, especially a bit later in the year.

Sadly the mist has now covered all of the sky, Jupiter is surrounded by a glowing halo. First I lost sight ot Io, then Ganymede and Callisto vanished. Well, it was a good view while it lasted. Tomorrow's forecast seems a bit more promising.

I'm enjoying excellent seeing on the gas giants at the moment. I only have the small Mak set up but it gives plenty of detail, can use x200 on Jupiter and x250 on Saturn. Waiting for the emergence of Europa from Jupiter's shadow around 9:30pm, just a bit worried the fog from the river may close in. Fingers crossed.