Ags

High density knots of dark matter have been observed in the core of large galaxy clusters, which was not predicted by current dark matter models. https://www.spacetelescope.org/news/heic2016/

That won't knock them out of orbit - but it will mean they need to launch a whole new batch of working satellites.

The International Telecommunications Union nominally controls this; by international agreement the licensing decision is delegated from the ITU to the launching nation's telecoms authority.

I am using it in Alt AZ mode on a Berlebach Report tripod.

It is still working out well. Good for visual and photography.

A dob of similar aperture looks tiny in comparison...

Now I am thinking about a 10" goto dob. Maybe one day!

True - I have to empty my hard drive after each session!

I took this a while back with my ASI178MM, C6 and AZ GTi. Lots and lots of 0.3 second exposures.

Why are all these people posing in front of a common-as-muck achromat?

Collimation is rarely perfect and it is possible for collimation to be a bit a little bit off and still see the bands on Jupiter, which are very prominent. To test collimation, point the telescope at a moderately bright star, use your highest magnification, and place the star at the very center of the field. Is the star symmetrical? If you can see the main diffraction ring, is evenly lit all the way round? Regarding contrast on Mars - remember the whole planet is layered with uniform fine red dust. The features we can see are consequently quite subtle.

Aperture fever family intervention.

I am glad the big dob is working for you. I will try my supermagnification theory tomorrow (imaging DSOs tonight) and invest in 8 and 9 mm eyepieces. Maybe someone will invent a diffuser lens to increase the size of the exit pupil without reducing the focal length of the telescope...

I have heard binoviewers can help, but I don't get on with binoculars so I don't fancy the investment. Also I see plenty of floaters staring at a blue sky, so I don't think it would be total solution. My setup is built around the AZ-GTi and the C6 is the biggest aperture you can put on that mount. Maybe in a couple of years I might get a C9.25 though...

With that ZWO camera you can do planetary imaging, EEA, and it's a better camera for DSO than any unmodified DSLR. Also, its small pixels are a better match for the small scope or camera lens you are likely to put on a star adventurer. I got a DSLR for Astro and thought I would use it for general photography too, but 99% of the time the camera I use is my phone. For Astro I now use an ASI 178 MM and I am much happier not constantly fighting with my DSLR.

Being mischievous, I would strongly consider spending my 500 on this... https://www.firstlightoptics.com/zwo-cameras/zwo-asi-183mc-usb-3-colour-camera.html

I am toying with the idea of "supermagnification" - using outrageously high magnification on Jupiter so the planet's disc is much larger than the floater blobs... I'll try this tonight.

Mars has a Dust Cycle of around 18 years I think. Winds blow dark regions clear of dust, darkening them, causing the planet to absorb more energy from the sun, causing more wind (and leading to media reports of "global warming on Mars"). It reaches a tipping point and when the sun is strong on Mars (corresponding to a point in its orbit we would call a favorable opposition) and the extra heat in the Martian air blows up into a global dust storm. This causes dust to settle on all the dark regions, lightening them slightly and cooling the planet, so it takes years before the next global dust storm. There was a global dust storm last opposition, so the contrast in dark regions will be lower this time. I looked at Mars with my C6 a couple of weeks ago - the polar cap was very prominent and dark regions were quite visible. It does seem that some people's eyes struggle to see details that are very apparent to other observers - could it be related to the high surface brightness and redness of the planet?

I used to find that an exit pupil or around 1mm kept the floaters away, but now I am finding that I need at least 1.5mm exit pupil to see anything on the planets. So frustrating! My 6mm SLV is very nice but at just under 1mm exit pupil it's like looking at Jupiter through a snow globe! I used to be able to shake my head and get a few seconds of clear viewing, but that don't work no more. As I can't go bigger than my C6, that means I am stuck with a magnification of 100x (maybe 120x at a push). Sad face. I read somewhere that as you age the floaters soften and liquify and eventually go away. Can the retired SGLers attest to that?

Seeing was very bad; Jupiter was positively vibrating on my screen. I failed to find perfect focus. I tried 5 ms subs to compensate for the seeing, but it didn't help much.

M12 Bolt with Explore Scientific Dob Counterweights.

Yes, simples!

APOD! A very inspiring work of art.

I would say so - that's all I do and it gets me within half a degree of a target quite reliably.

I think it automatically adds info from each goto to its model, as you center the object then confirm. I can't the source where I read that though. The AZ GTi does a really good job of goto though regardless of whether it refines the model.