John

Similarly to Stu, I just enjoy what there is to see. I'm retired so late nights are not a problem really. I'll do some more white light solar observing now that the Sun is waking up. Lots of great deep sky targets once it does get dark.

I don't seem to have major seasonal changes in the way I observe. The targets change but it's nice to welcome each season's old friends back as well as trying to spot some new stuff 

52 minutes ago, banjaxed said:

I am not familiar with this mount but notice you have owned it for “quite a few years “. Could it possibly be worn or has it always had this problem.

Thanks for the reply. This issue seems to have become more noticeable over the past few months.

It could be a case of wear but I'm trying to work out where that could be happening. The locking mechanism is very simple - just the pressure exerted by a screw on the axis shaft with a brass plug / bush in between the end of the screw and the axis shaft surface.

2 hours ago, Nik271 said:

I used the mobile version of Stellarium on my phone. Interestingly I just loaded my desktop version of Stellarium and it gives 7.80  for the same star  They must be using different databases. Or perhaps the mobile version gives a compensation for the atmosphere?

The mobile version of Stellarium is not produced / maintained by the same people that produce the desktop version as I understand it.

8 hours ago, SuburbanMak said:

Thanks John - I am still pretty near the beginning of my astronomy journey but immediately started to get real satisfaction from doubles.  The main scope I’ve been using is a 127 Mak which is no slouch in this department but I’ve noticed that for some pairs the 60mm performs brilliantly. Polaris in particular just pops in the smaller aperture & colour contrast is superb. I’ve split tighter pairs in the Mak, right down to its optical limit (Tegmine for example) but Polaris sits much better on the 60mm optics, I reckon just as a function of where the diffraction patterns fall at focus. 
I’ll be very keen to point the Hilkin at Rigel & then Sirius come the winter. 
 

According to this article a 60mm scope can resolve equal brightness pairs down to either 2.2 or 2.3 arc seconds (Dawes Limit vs Rayleigh Limit). Unequal brightness pairs get more difficult to split as the brightness difference between the component stars increases with Sirius being one of the most extreme examples. There are some good test double suggestions in the article:

https://skyandtelescope.org/observing/pushing-limits-a-spring-sky-double-star-romp/

Gamma Virginis, Izar, Iota Cassiopeia and Delta Cygni are ones that I frequently visit at this time of year. Usually though 100mm is my smallest aperture.

Overall I'm a big fan of the Skytee II mount and have enjoyed using mine with a variety of scopes for quite a few years now.

I've got the slow motions adjusted nicely so there is practically no backlash on either axis.

The only remaining gripe that I have with the mount is a small movement around an axis (alt and azimuth) when I lock it.

The amount of movement is quite small but it is enough to push a target just out of the field of view when using high magnifications (eg: 200x plus).

I've been scratching my head over what might be causing this

I've tried removing and checking the locking levers and the brass inserts that they tighten. There is a brass plug / bush below each one that bears against the axis shaft but I assume that is normal. The levers seem in good order and I keep the small screws that hold them in place tight.

The axis of the mount are well lubricated and the mount moves very smoothly when the locks are loose and also when they are tight and the slow motion knobs are used.

I can't understand why increasing the pressure of the locking screw against the axis shaft, to lock it, should result in this small rotation of the shaft 

Has anyone else experienced this and, if so, does anyone know of an adjustment that stops it happening or at least reduces it to a minimum ?

Many thanks

Lovely lunar views tonight with my 100mm refractor.

The Rupes Recta (the Straight Wall) is right on the terminator tonight and the sunlight is just catching it's higher edge and "the Scimitar" feature while the rest of the floor of ancient Thebit is in darkness. The ramparts of the crater Birt are high enough to catch the sunlight as well though standing out as a gleaming crescent against the pitch black plain below with the black pock mark of Birt A embedded in the brightness.

Nice illumination of this well known area

Many other features looking good as well. Very thin, hazy clouds around but the moon is shining crisply through those at the moment.

Nice scope. My first scope was a 60mm F/13.3 Tasco. It's optics still perform well despite it's rather wobbly alt-azimuth mount and .965 inch eyepieces. I must get an adapter sometime so that I can try some decent eyepieces with the scope.

I was rather surprised how well a small aperture scope can do on double stars when I recently stopped down my ED120 refractor to a 52mm F/17.3:

8 minutes ago, Stu said:

No go here, quite hazy and clouds over the nova. I’ll update the graph in the morning with any observations posted tonight.

Cloud and light rain here so nothing doing this evening from me I'm afraid

"Medical news - surgeons laboured to remove a 2 metre truss pole from a Surrey man today. His condition is described as stable but possibly uncollimated"

2 minutes ago, Captain Magenta said:

I’ve found that my LZOS 105 takes a fair while to cool down such that the extra-focal spikes disappear. Obviously dependent on temp difference but 40 minutes at least is a rough guess.

My LZOS 130 F/9.2 takes about 30-40 minutes to fully cool.

18 minutes ago, Stu said:

Just to add..... I’m hoping to move down your way soon @John so should be able to benefit from darker skies at last! Hurrah! Time to finish that 12” truss dob project at last. I still don’t think my powers of persuasion are up to keeping the scope in the house though! 🤣

Get down here before the house prices catch up with the home counties

My 12 inch dob gets just as much use as my refractors and is no more hassle to setup. Possibly a bit less hassle than the 130mm frac.

Circumstances are a key part of how often larger scopes get used though.

1 hour ago, scotty38 said:

Thanks and I may set the scope up in readiness tonight depending on the weather. I still think it's my eyes that are the limiting factor for me as the views in my binoculars were better than my scopes. In fairness I spent maybe an hour or so with the bins before I got the scope out so maybe I'd left them to get too low. There was no way I was getting anything like you saw but will persevere....

Because they are low in the sky, they are made additionally difficult to observe because we are looking through so much atmosphere.

I snapped this pic of Mercury this time last year using my mobile phone held with a clamp against the scope eyepiece. Much enlarged, you could just about make out the phase of the planet back then. The simulated view is from the Virtual Planet Atlas software which confirmed the phase at that time. In the eyepiece of the scope Mercury looked quite a lot smaller than this:

The starlinks were quite a feature of observing last night. I saw two major chains, the compact pair that you saw and earlier one of around a dozen separated out so at one point the chain spanned around 1/3 rd of the southern sky as they processed across.

Added to that numerous other satellites whizzing through the field of view and I'm sure there will soon be a demand for a new section of the observing part of the forum - "Man Made Stuff" !!!

Well done for seeing both !

Mercury in particular is only easily visible during quite short windows of time and is never high in the sky.

I managed to have a look with my 100mm scope a couple of nights back and could just about make out the phase of the planet but it's disk is small - just 8 arc seconds in apparent diameter.

Going, going .......

Another day or so and it will be back at the mid mag 7's which is where it was when I first observed it on the 20th March.

Plus, Messier 52 has never had so much attention !

I've had a nice relaxed evening observing under generally good skies this evening using my 100mm refractor.

A feature tonight were the starlink satellites of which there seemed to be many, streaming across the sky. One bunch, that were closely spaced, had me thinking that some piece of space junk was re-entering and breaking up for a moment - until I looked through my scope's finder and saw the individual points of light following each other.

Anyway, back to the starry skies, Hercules was well presented so naturally I took a look at the two magnificent globular clusters Messier 13 and Messier 92. Both lovely and showing some nice surface star resolution at around 125x magnification.

A glance at Stellarium reminded me that there is another globular cluster in Hercules and one that I can't recall observing before, NGC 6229. So that became my next target.

It is not too difficult to find and forms a neat triangle in the low power eyepiece field with a couple of magnitude 8 stars. The cluster is magnitude 9.8 so quite a bit fainter than the better known M13 and M92 but NGC 6229 is further away from us, a lot further away, and is termed an Outer Halo Cluster. It's distance is nearly 100,000 light years compared with 25,000 and 26,000 for Messiers 13 and 92.

Despite being fainter, NGC 6229 stood out reasonably clearly, once the scope was pointed at the right spot, as a concentrated misty ball of light at 37.5x magnification and increasing the magnification increased the contrast against the background sky but did not show any obvious resolution into stars with the 100mm aperture scope. Next time that I have my 12 inch dobsonian out I will re-visit this ball of stars and see if that can resolve any of them.

Very nice to observe this trio of globular clusters. Some of the most ancient, exotic and fascinating objects we amateurs observe IMHO.

2 minutes ago, JeremyS said:

Binoculars or Tak FC 100, @John?
 

Ooops !, sorry Jeremy I should have said. 100mm refractor @ 37.5x magnification.

I feel that Nova Cas v1405 has faded a little more from this evenings observations.

The closest match from the surrounding stars was with HD 220167 which is listed at magnitude 7.15 or 7.18 depending where you look.

To my eye the nova is dimmer than the nearby star HD 220819 (mag 6.6) but still brighter than the mag 7.8 HD 220770 which is close to Messier 52.

So I'd settle for mag 7.0-7.2 for the nova tonight.

Hopefully I'll get another look tonight. Fairly clear here currently.

The best "accessory" for getting more out of astronomy whatever scope you use - retirement 

Refractor plus shrubbery. Target = the moon

It should be OK at low to medium power without much cool down. My 12 inch solid tube does OK in that respect.

Just now, John said:

Very nice !

I had the older solid tube, non-GOTO 10 inch Skywatcher dob for a while a few years ago. That had 6 mirror clips as well.

I wondered at the time whether that was linked to the mirror glass of the 10 inch being Pyrex but there is probably no connection.

Hope you enjoy the scope Michael

Actually I've just noticed that they don't use the 250PX coding now - it's 250P. Maybe Pyrex is no longer used ?

Very nice !

I had the older solid tube, non-GOTO 10 inch Skywatcher dob for a while a few years ago. That had 6 mirror clips as well.

I wondered at the time whether that was linked to the mirror glass of the 10 inch being Pyrex but there is probably no connection.

Hope you enjoy the scope Michael