Nik271

I had a binocular session last evening in between gaps of high fast moving clouds. I had heard that T Lyrae is a pretty carbon star so I hunted it near Vega. Eventually I found it but it was quite dim (I estimate near 9-th magnitude) and the colour was not showing well in the binoculars. Will try again with a telescope the next clear night, perhaps today if the weather forecast holds true.

Last winter I observed R Leporis: Hind's crimson star, which has striking deep red colour. You need to observe it in winter when it's as high as possible. Here is some more info from another post:

PS. Actually in almost any binocular there will be a small misalignment but the brain can deal with it up to certain point. If your eyes get tired or you get headache this is a sure sign of large misalignment. Also if the left eye view is shifted right that's fine, we just interpret this as stereo vision. View shifting up, down or leftward ( from left eye ) is really bad as brain is not used to it.

If you have found the screws you are halfway there. The other main thing is how to measure miscollimation more precisely. Here is how I do it: in daytime set binoculars on a tripod and focus on a distant target, it has to be far enough that you cannot observe the parallax between your eyes. Set the IP distance so it fits your eyes and then gradually move your head away from the eyepieces by about 20 -30 cm while keeping looking through them switching from left eye to right and back You will find that even a small misalllignment in the two views is greatly magnified this way and with the screws you will be able to adjust. Bear in mind this way the binoculars are collimated only at this IP distance so it's is not a perfect fix.

I've been waiting for Dubhe to be higher in the sky to give it a serious try with my 180 Skymax. These days Dunhe is almost directly overhead in the early hours of the morning,and hopefully this weekend there will be some clear sky to give it a shot.

I had a brief clear spell last evening but the seeing was poor. I looked at Jupiter for 20 mins following the progress of Europa as it disappered behind the limb, but very little detail on Jupiter was visible. By 9pm the Moon was higher and I looked at Pythagoras and Mons Rumker in the north and also the big oval of Schickard in the south. Again it was not possible to use more than x120 magnification. I was looking for Rima Sharp, but couldn't see it. Tested the seeing with the double star Gamma Arietis, which is quite an easy one. The two components were dancing about, so I decided to give up with the rest of my planned double stars selection from @Ags 's book. Just as I packed high clouds covered the sky. Better, more stable weather is hopefully coming after the weekend!

I believe Celestron pioneered the mass production of the Schmidt corrector plate and still hold the patent for the method. Other companies probably decided it's not worth investing in new R&D for SCTs when the market is already so dominated by Celestron. I would guess that the SCT line-up is Celestron's major revenue source and they are milking it for all it's worth. The new affordable Classic Cassegrains and RCs coming from Taiwan will give them some further competition though.

There was a lucky break in the cloud cover last evening and I managed to test it with a 6 inch F/5 Newtonian on many targets. At F5 and 750mm focal length the EP is giving x50 magnification, 1.4 degree real field of view and 3mm exit pupil, which is very suitable for DSOs. The full report is linked below, here is my verdict. I found the performance to be so-so. I estimate at F5 it is sharp only in the central 50% of the field, outside it the stars become increasingly comet like. There is nothing surpising about coma, I was fully expecting it, but my BST starguiders did seem better at the edges and the views were somehow more satisfactory. This is a personal thing I guess. Smaller star clusters which can fit in the sharp central part looked great. The large ones like the Double Cluster were disappointing to me since always one part of it was slightly out of focus. Having said that the views of some double stars like Almach and Achird were quite nice. If you are thinking of widefield views and have a fast scope my advice is: get a 32mm Plossl or save up for some quality glass from expensive brands. Here is the full report:

An 8 inch F/6 dob is the best 'jack of all trades' according to many people. In my garden a dob will not work well because I have high fences and houses nearby. An EQ mount gives me crucial extra meter of height and this way I can view objects down to 15 degrees in altitude. This covers a lot of summer targets and the gas giants in the past 2 years which have been pretty low.

I have the Skywatcher Skymax 127 and the Skymax 180. The Skymax 127 is my most versatile scope, easy to set up and use. I use the 180 for tough double stars and planets, its quite heavy at nearly 8kg, so a bit more effort to mount. When properly cool it really shines on close doubles.

It has been pretty poor this week weatherwise and then last night there was an unexpected break in the cloulds from around 7pm. I normally observe with Maks, this time I chose the 'neglected one' usually sitting alone in the cupboard, namely my 6 inch Newtonian. I was going to test the new SVbony 15mm EP on a fast scope, so I made sure the scope is perfectly collimated over the weekend and it was ready to go in the shed. Set up was very quick, took just 5 mins to put on my manual EQ5 mount, attach finder, counterweight and ready to go. The scope was already at ambient temperature so no need for cooldown. I used the 15mm Svbony giving x50 mag and 3 mm exit pupil, good for open clusters, and the 6mm Svbony giving x125 mag for double stars and planets. I am spoiled with Mak views of tight stars and contrasty planets. So the beginning was a bit of a let down: Jupiter with the 15mm was small and had noticeable diffraction spikes. The 6mm improved the view, the spikes were still there but at least I could see some cloud belts. I could see immediately that there was coma in the outer 50% of the field as the further Galilean moons resembled small comets. Then to the Moon which was just below Jupiter. This was much better, I guess coma is harder to see and the terminator line was sparkling sharp in the centre of the field. Very nice! The sky was clear but not very transparent so I decided to try with some double stars next, Not a task suited for a Newtonian but I was curious. First target was Zeta Aqr. The 15mm showed an yellowish irregular looking dot but x50 is too litttle for this close double. The 6mm was able to resolve it! Two very close touching dots oriented at 45 degrees from the sidereal drift, that makes it SE-NW direction I guess. Not too bad for this Newtonian and the seeing was mediocre. A Mak will produce smaller stars without spikes but the 2.3'' separation is never going to be easy. At least this shows my collimation was good. The next few double stars were easier and fun: Gamma Arietis, Almach and Achird. All three showed very nicely even with the 15mm EP at x50 and the colours of Achird and Almach were very pleasing. I tried one more tough one: Nu Ceti. The companion is 8'' away and 4 magnitudes dimmer than the primary. The 15mm failed to show it, but the 6mm created enough separation from the primary and there it was directly east. I though it was slightly blue. Since I was in the area I looked at Uranus with the 6mm. Very clean (and tiny) bluish-green disc. Then it was open cluster time with the 15mm. I looked at M36 and M37 in Auriga, M34 in Perseus and of course my favourite, the Double Cluster. Te views were sharp only in the central 50% of the field which was ok for all of them except the DC. It was not possible to fit both of the cores of DC in the sharp central area of the field. I should have been using a wider EP of course for DC but I stayed with the 15mm because I wanted to test it. Conclusiion: fine but don't expect tack sharp views of extended objects. I scanned through Hyades and Pleiades, they are too big to fit in the view of course, but even partial views are nice, I get to appreciate how many stars are there. I spotted Ceres, it has moved quite a bit from Aldebaran since last week and now is passing near the central hexagon of the Hyades. It was 9pm and clouds were rapidly filling the sky. I had time for one more object, the blue snowball nebula, NGC7662 in Andromeda. It was almost overhead, which makes starhopping difficult and focuser position ends up in unexpected places. It was a strange experience to me, used to the convenience of mirror diagonals at the end of the scope :- ) Anyway, I found it with the help of Stellarium, it is very near the 6-th magnitude star 13 And. The blue snowball was just a fuzzy star in the 15mm but the 6mm resolved it into a obvious disc, quite bright. I didn't spot the blue colour. It was time to pack up. It was a lucky unexpected observing session and I was glad to say that my neglected Newtonian did quite well. Its strength is in the wide views of clusters but I found that it can show some double stars as well. The 15mm Svbony did so-so, I will add a short update to my review of it in another post. Clear skies, Nik

In most situations going for 0.3mm exit pupil is too much, I think only the Moon is an exception. 0.3mm exit pupil means using magnification more than 3 times the aperture in mm which is very rare and most scopes will not support it. I think 0.5mm exit pupil is more reasonable.

The sky was milky with high cloud and I had a try at some bright doubles in Cetus: Gamma Ceti and Nu Ceti, with Skymax 127. Normally it's a good performer but this time I failed miserably on both. I blame the seeing. At least I saw the famous variable Mira (Omicron Ceti) and it's optical double nearby (2 arcminutes to north east) . The literature says that Mira itself is a very close, very unequal double with separation only .5'' currently. Well beyond my sky and telescopes. Still it was nice to be out.

The weather is not very promising in the next few days unfortunately. The next clear sky is forecast for the weekend. It's a good season for the Cassiopeia open clusters and this is what I'm planning to test it on.

The moons are far dimmer than the planet and I guess it is simply that Uranus is overexposed thus swamping any colour. It's a great photo still!

I did a comparison of SV154 against the 12mm BST Starguider on Jupiter one night (in a F/12 Mak). They were very similar in the centre, very little light scatter from both. At the edges the BST was sharper, considering its FOV is 60 degrees vs Svbony's 70 I think it's to be expected. The eye relief of the BST was much more comforable with the larger and deeper eyecup which is a big plus for it. I also note that in cold weather the front lens element mists up easily because of the proximity of my eye to the lens. I'm planning to test it on my F/5 Newtonian to see how it performs with a fast scope. I'm going to take it out the next clear night for some open clusters views and report.

You've captured some of Uranus satellites as well, very nice! Is this a mono camera? Uranus looks usually green-blue to me.

I bring my scopes into the house overnight after observing precisely for this reason but I have Maks which are very compact. One option is to put your Dob back in the shed with the front cap open(just cover with a towel to stop dust). Once dry put the cap back on the next day.

Well done, Kon! I have seen some green colour in M42 with a 6 inch reflector but never red. Last night was very clear indeed, lets hope we get lots of these this winter.

That's pretty close to what I can see visually on Jupiter this season even with much bigger scopes.

Sure, I'm glad that it's useful. I have found the mobile version of Stellarium to be more accurate for positions of asteroids than the desktop version.

The largest asteroid Ceres is passing very close to Aldebaran this week. I took this short stacked image of the Hyades (10x2 seconds from a tripod). The position of Ceres ( at 1 Nov 21:00 UT) is marked in the second photo. It shoud move fairly rapidly in the coming days.

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.