Nik271

There are a lot of 7/8-th magnitude stars in this area, so careful star hopping is needed. It will help if you have a 50x9 finder on your Dob, not the more common RDF or 30x6 because they will not show you the dim stars. My way to find Neptune is to look for the conspicuous triangle of Psi 1,2 and 3 Aquarii. these are 4-th mag so easily visible. Then identify Chi and Phi Aq which are 1 and 2 degrees higher than the triangle. Still very bright 4/5 magnitude stars. Finally move east and horizontally about 5 degrees from the midpoint between Chi and Phi (directions are for about midnight UK time in early August). You will see a number of 7-th magnitude stars and Neptune among them should have a bluish hue. To check for sure use higher power and it will show as a small disc, only 2'' across, but well within the resolution limit of a 150mm Dob. Good luck!

Here is a screenshot from Stellarium with the Saturn's moons at midnight tonight. As you can see they are usually all bunched together near Saturn which is the main difficulty with seeing the brightest of them.

In addition to Titan with 10 inch scope you should easily spot Rhea, Dione and Tethys, which are around mag 10. They are quite close to Saturn and often hide in its glare but I've seen them with a 7 inch Mak so a 10 inch wil make an easy job of them. Iapetus is another easy one when it is west of Saturn and it is mag 10. Just beware that at the other end of its orbit when it is east of Saturn Iapetus dims by 2 magnitudes to mag 12 and will be difficult to spot. Iapetus is also much further away from Saturn and the main difficulty is not to confuse it with a background star. Stellarium shows all the Moon very accurately, it's what I use to identify what I see when observing.

I managed to grab a quick view between clouds this morning. There is a pair of sunspots south west, which appear to be new, a welcome change from the spotless few days we had recently. They are also showing up in the recent SDO image but without a number yet. The seeing was quite decent at 8:30am, sadly the clouds arrived immediately afterwards.

I use a 180mm Skymax on manual EQ5 and the mount can handle it, especially if you don't extend the legs. But with all the accessories on it the EQ5 is on the limit, I take care to balance it perfectly. Cooldown time is (I estimate for the 180mm Skymax) about 1 hour for each 10 degree temperature difference. You don't need a perfectly cool scope for x100 but if you want to go to x300 then it must be in perfect thermal equilibrium. Bear in mind that during a clear night the temperature keeps falling and the Mak may not be able to catch up for a long time if it starts warm. From personal experience 90% of the time the seeing conditions will dictate how much detail you can see and a 4 inch scope will be able to show you just as much in all except very good seeing condition. When I expect seeing to be poor or average I use my 120mm (officially the 127mm) Mak, very compact and capable. My advice is that both of your options - 4 inch refractor or 6 inch Mak are good, the refractor is quicker to set up but at F11 a bit unwieldy. The Mak sometimes will show more due to its aperture (seeing dependent) and is more compact but needs cooldown. I say just go for one of them and don't feel you are committing too much. If you buy quality you can sell it later if you decide to switch to something else. People bought a lot of stuff during the pandemic (myself included!) so you may find some good and hardly used scopes in the sell section.

Canon lenses are quite good esp their pro L lenses, but the fast primes are very expensive compared to the third party alternatives. One reason for their high price is that they have top quality autofocus and/ or image stabilization but this adds to the cost, and you need none of that for astrophotography. A purely manual lense gives the best value for money.

The closest crater to the Apollo 11 site which is resolvable in amateur equipment is Cat's Paw, visible just to the left of the landing site in the photo in @Craney 's post. It shows up just barely in images taken with a 5 inch Mak, so a 200mm scope should be able to show it well. Never seen it visually though. Armstrong and Collins are easier. Of course the holy grail is to image the actual landing module! During the lunar morning it may cast a long shadow, say 100 meters, but even then I think it's beyond the atmosphere resolution limit from planet earth.

I have been tempted by the GoTO mounts but what always puts me off is that you can't operate them manually for precisely such eventualities or when you want a quick visual session and can't be bothered with the electronics. I have EQ5 and I wish to get something a bit sturdier and professional in the future, but they all seem to be motor driven only.

Yes it's Lowell with a slightly bigger refractor from the same period 😀

Nice! Just beware, it's a slippery slope, soon you may look like this chap 🙂

Yes, I have the the 180 Skymax from Skywatcher and I highly recommend it for planets, double stars, globular clusters, basically everything small that needs high magnification. As for double stars there is a lot of interesting history and information about them. This book for example is a good starting point without being overwhelming. Double & Multiple Stars, and How to Observe Them by James Mullaney Clear skies! Nik

I observe double stars, they are quite resistant to moonlight or indeed all forms of light pollution. You can also observe the Sun with appropriate filter in place, so not even have to wait to get dark 🙂

An update: I managed to split the close AB pair of Mu Cygni last night 🙂 Used the 127 Mak and 6mm EP giving x250 which was just about right for the conditions. The seeing was decent, neither great nor poor and the secondary popped out NW of the primary after staring at it for a minute or so. Star D was very prominent 3' away but I could not spot the dimmer C and F as it was not totally dark at 11pm. Surprisingly the AB split of Mu was cleaner than splitting Delta Cygni later the same night despite Mu being much lower in the sky and with closer separation, probably because of the much smaller difference in magnitudes. The little Mak performed very well again. All in all a good end to this spell of good weather! Cloud and rain forecast from tonight

I'm sure everybody knows about that one but here it is anyway: Barnard's star is the closest to us after the three members of the Alpha Centauri system and so the closest star visible from the Northern hemisphere. It's also the star with fastest proper motion known: it is running along at a good clip at 10'' per year! Edward Barnard discovered and measured it in 1916. The star is a red dwarf with mass 1/7 of our Sun which means it is both older than the Sun and it will live much longer, for trillions of years (assuming the universe lasts that long). Summer is the best time to see this famous star, as it transits the meridian at about 11pm summer time at about 40 degrees altitude from the UK in July. And now comes the bad news: being a red dwarf Barnard's star is dim, only mag 9.5. I managed to see it yesterday with Skymax 127 and 15mm EP, but really I should have been using wider EP, to aid the star hopping. The star hop is non-trivial since you probably won't see the star itself in your finder. I started at Cebalrai (Beta Oph) then moved east to 66 Oph passing a nice optical double: HD 162648 and HD 162649 From 66 Oph the stars get dimmer, I moved 1 degree north west to a pair of 7-th magnitude stars in a line with 66 Oph then hopped back one step across them to an empty space and looked at the EP. And the Barnard's star was there! Here is my last hop: You know you are on the right track with the last hop when you pass an 8-th magnitude star halfway. Barnard's star is red but I think you need aperture to see this, to me it looked like just an unremarkable lonely dim star out there. Still I'm thrilled to even find it - there are not many red dwarfs visible in small apertures. Go on, find it, take a look and see if you can spot the colour! Nik

These are really really impressive! Makes me realise that unlike Deep sky imaging with the gas giants it's not possible to get back a few days/months/years later on the same target. You basically get 10-15 minutes (I guess), after that even de-rotating will not help as the clouds on Jupiter move fast at this scale..

Interesting read, there are lots of stars to see in that system! Needs both excellent seeing and transparency for the dim ones.

Catch them if you can, there are SIX ARs today (none of them big but it's a start) 2849 is the newest one, on the limb

Thanks for the suggestion, John! I will try Mu Cygni with my small Mak, at 120mm it should be doable in it.

Thanks for the head-up, the photo is very clear! I spot even 5 groups in it, looks like a promising week of activity. And a forecast of almost uninterrupted sunshine here for a few more days 😎🤞

Venus is only 10 degrees in altitude and what you are seeing are the effects of dispersion of light in the atmosphere. This is most noticeable in bright objects like Venus (or Antares low in the south) and the rainbow colours should be horizontally banded. Collimation will not produce chromatic dispersion, if it was collimation you will notice that the stars don't come into perfect focus. Don't test this on Venus but on ideally on Polaris, which does not move so much easier to use high magnifications. Try the 5mm EP and examine the star shape. It should have a symmetric circular shape of concentric rings with 4 spikes. Collimation is perfect if everything is perfectly circular. (You should also be able to see the Polaris companion as well, a dim 9-th magnitude star 18'' away from the main star.)

I'm predominantly visual and I like the immediacy of actually looking at the eyepiece rather than a computer screen. But then it's nice to have some picture to share of a special or famous object and sometimes I want to image things just to make sure they are really there Last autumn I wanted to confirm for myself that the Andromeda galaxy is more than just a blob and so one night I imaged it to see if can get the spiral arms. It was very exciting when these showed up after stretching the image in the photo editing software. So I completely get the excitement of imaging, there are lots of technical challenges there which is what I think makes it appealing to many. For me I've decided to stick mostly visual, and keep my DSLR with a T-ring pre-attached just in case

Today is another good day for observing the Sun (a positive aspect of this heatwave :) ) I was out at 8:30am with Skymax 127 and spotted a new region 2846 has rotated into view, it has two or three spots and quite a lot of bright faculae around. Meanwhile AR 2842 has developed nicely into a bunch of spots, I counted seven, just when it is on the way to the edge. The seeing was pretty good, could see hints of the granulation already at x150. Nik

Glad to be of help! This is a pretty good image with lots of detail visible. The 127 Mak can do even a bit better when the Moon is higher in the sky (usually in winter or spring) and of course with good seeing and stacking. Nik

I saw something like this in my Mak at x450 Except that the diffraction rings were thicker because of the central obstruction and much fainter after the first one. Just checked that Dubhe is listed as BU 1077 so it was discovered by S. Burnham. I wonder if he did it with his own Clark 6 inch refractor or had to use the big refractors at Lick or Yerkes.

GRS used to be much more red in the past, especially when it was discovered, hence the name. Nowadays it is brown-red, rusty colour and has become paler. I agree that the rest of Jupiter in good seeing beats the GRS.