PhotoGav

Damn! Good luck sorting out the issue.

Hi Tony, I have a Mesu 200 mount (not e series - don’t know if that matters?) with sitech controller and I’m in Wiltshire, not too far from Oxford. I’m very happy to help if I can. Here’s a pic of my controller system, is it the same as yours?! Ah, reading your post again, looks like you have version 1 and mine is version 2, so possibly no use? Let me know.

There are three kinds of Lunar libration: libration in longitude, libration in latitude and diurnal libration.

You describe libration in latitude above with the cause of the Moon ‘nodding’ being down to the tilt of the Moon, 5.1° to the ecliptic and 1.5° on its axis; meaning that sometimes it is above the ecliptic and we see more of its southern region and sometimes it is below the ecliptic so we see more of its northern region.

You also describe libration in longitude, the ‘shaking’ of the Moon from side to side, resulting in us seeing around the eastern and western edges. This is due to the elliptical nature of the Moon’s orbit. When it is closer to the Earth (around perigee) it is traveling faster, so it has orbited a bit more than usual, meaning that we see around more of its eastern limb (right side), and when it is further away (at apogee) it is traveling slower, so has orbited a bit less, meaning we see around its western limb (left side). (I think I have my Lunar East and West the right way round! Always confusing!).

Finally there is diurnal libration. This is a form of libration in longitude, i.e. ‘shaking’. At moonrise, we can see a bit further around its eastern limb and later that night, at moonset, we can see a bit further around its western limb.

All this libration means that despite the Moon being tidally locked and always showing the same face to Earth, we can see a total of about 59% of the lunar surface. The first time we saw the far side of the Moon was in 1959 when the Russian spacecraft, Luna 3, photographed the Moon whilst in orbit and radioed back the images to Earth.

I hope that helps and makes some sense. 

11 hours ago, Ags said:

Being outside is the whole point of astronomy for me. I can sit inside with a cup of coffee watching some monitors whenever I want 😀

Absolutely, Astronomy happens from outside under the sky, though of course, a clear sky is still needed to enjoy monitors as data is being gathered, and that can be a rare thing! My visual Astronomy really took off again once I fully automated my imaging dome, so thank goodness for how far AP has come! That can now be ‘fire and forget’, leaving me time to go to my other observatory (I run the Blackett Observatory) and enjoy showing people the skies there! Whatever form it takes, Astronomy is so wonderful and the general public’s interest in it seems to be growing. 

That made me chuckle. I let the dog out an hour ago. I stood in the garden, about where I used to set up my picnic table for the laptop in a cardboard box, looked up at the beautiful sky and thought to myself how I missed those times, sitting outside, waiting for a sub to complete, leaning back in the picnic chair and just taking in the heavens. Tonight my dome is running and I’m lying in bed monitoring progress on the iPad!

Beautiful images. Do you use flats for these?

Close up with Lunt LS50THa, Chameleon3 and 2.5x PowerMate. 1000 frames, 15% stacked.

Full disk with a Lunt LS50THa and Chameleon3 camera. 1000 frames, 15% stacked.

Here are some attempts at the Sun with a Lunt LS50THa and Chameleon3 this morning. I used a 2.5x PowerMate for the close-ups, with the Televue adapter which arrived from FLO in good time this morning. I was using another adapter before and these shots with the new adapter seem to be sharper / clearer. Perhaps the spacing is better for the PowerMate now?

I experimented with full disk flats and failed miserably! The full disk shot has an ugly highlight as a result. Apparently a cereal bag placed away from the objective is the way forwards - I will try that tomorrow. Does anyone have any advice and photos of the set up for whole disk flats, please?

For comparison, here's a close up from yesterday, using the old adapter:

Enjoy the sunny skies!

Gav.

Your longitude also has an impact on where things appear and when. Cyprus is at least 30° further East than the UK, so the same object will culminate about two hours earlier out there in Cyprus. So, at 19:00 UTC, Mars is significantly closer to setting in the West for you out there than it is for us here in the UK, hence at the same time UTC it is lower in your sky. If that makes any sense. When it culminated it would have been higher in altitude in Cyprus than in the UK.

Thank you @Kon, @Mark at Beaufort & @geoflewis - I was torn by which set up to use to try and capture the occultation - wide-ish or in close with the planetary camera. I opted for the wider and am not convinced it gave the best pics, but it was good to be able to see the event and have an overview. Obviously, more telescopes needed for next time!!

A cold start to the day, almost scuppered by cloud, but managed to grab a few shots. The neighbour's garden got in the way at the end!

Ha! Yes, the EM-500 is a big old thing, it’s carrying a Mewlon 300 - not a bad scope! I had a bit of a wander around the skies once aligned, lovely views of Jupiter, core of M31, Ring Nebula, M15, Almach, the Double Double and the Owl Cluster. Tried Mars too, but too low and was a featureless orange blob!

I am happy to report that some washers have provided the necessary tilt to the pier adapter. I successfully polar aligned the mount this evening and all is good. Thank you all for your help and advice.

Thank you for the suggestions. I’ll take the mount off the pier later in the week and hopefully it will be obvious what the best approach will be. But please keep coming with ideas!

Perfect, thank you folks, that makes sense. Engineering solutions will be worked on!

Are there any issues with adding in a tapered slice to tilt the mount backwards enough to allow alignment? Given that the mount would no longer be level, would it affect the performance in any way? (I am wondering if that is a really silly question?!??!).

Also, do you have any suggestions for suitable manufacturers of such a tapered slither?!

Thank you.

Don't worry, I've seen the web site at the bottom of the specs and have found that online. Thank you!

Thank you for the swift responses. The thought had crossed my mind that it might be for lower latitudes, but I couldn't find any details anywhere. @CraigT82 where did you find those specs?

That answers the problem perfectly and I now have a solution to pursue. 

I am helping a friend get their observatory up and running with a Takahashi em-500 mount and I have come up against a problem… I was trying to polar align the mount yesterday evening and it just won’t reach a high enough altitude to get Polaris into the polar scope reticle. The mount gets stuck against the ‘cradle’ piece just above the altitude adjustment bolt. Here’s a pic:

You can see the scratch marks where it gets blocked. From the side views, it looks like the two parts of the mount are slightly out of alignment:

My final question is: what does the bolt in the middle of the black logo ring do?

I’m hoping there is a Tak mount expert out there who will be able to help me out. 
 

Thanks,

Gavin. 

Superb, thank you John. I will see if I can tease my setup into Powermate cooperation! I love the mental image of you with Victorian photographer style black sheet over your head. And it works, makes it all easier to see! Look forward to more of your images. Gav.

1 hour ago, Hughsie said:

Hi Gav.
 

Other than the solar disc image which did not have any Barlow/powermate attached, I use a double stacked 60mm Lunt with stock Lunt B1200 diagonal. On this occasion I added a 4x TeleVue Powermate then a ZWO ASI174mm with tilt adapter. I apply unity gain for this camera of 189 and today I binned the camera 2x2. This enables me to work at low exposure settings and achieve high fps. 2,000 frames are captured and 10% stacked.

I also posted earlier this week images captured with the same equipment, swapping out the 4x powermate for a 5x powermate, again with the camera binned 2x2 to reduce over-sampling and achieve low exposure/high fps.

Flats are also acquired at the same gain using a crumpled old sandwich bag and lacky band!

Thank you John. So you just put the Powermate in the diagonal and the camera in the Powermate? You manage to achieve focus with no problem? I’ve struggled to find a good setup with my Lunt 50 and a 2.5x Powermate. 

Great results John, impressive! I'm interested to know the optical chain you employ for the close-up work, please?

Here is my quick capture of today's Sun (2022-05-08). Is it coincidence that the filaments appear to display the effects of the magnetic field lines winding up as differential rotation starts to have more impact?

Excellent stuff, thank you for the various explanations and thoughts.

As for NLCs, they are one of the finest displays we can enjoy here on Earth! We are now entering the time of year when they occur, so fingers crossed for a few displays over the coming couple of months.

Regarding rocket propellant, Leo, the fuel is liquid hydrogen (or kerosene in the case of the Russians) that is mixed with the oxidising agent, liquid oxygen, to give much combustion, expelling exhaust gases, serious thrust and some H2O!