John

The EQ3-2, EQ5 and HEQ5 are the same. The EQ2 is different. 

Having learned long ago about the vagaries of the UK weather, in all seasons, I keep my telescope and mount options extremely simple to minimise setup and take down times. Last night I had around 45 minutes of decentish sky conditions so out went a scope, I got some observing in, and back in it came when the clouds intervened. 

If my setup / take down times were more than a few minutes I doubt that I'd still be doing this hobby 🙄

5 minutes ago, melsmore said:

Not really night, but as close as it gets at 53⁰N at this time of year. First light for my new APM140, which I collected today from The Widescreen Centre. A low Venus and the Moon, briefly before they dropped below the treeline, then Polaris and Mizar. My GPD2 mount managed the weight (around 10kg) just fine for visual. Too soon to have a considered opinion, but very pleased with it so far.

Nice looking setup 🙂

I've been attracted to those 140's ever since they came out.

I managed to split Antares again this evening with my 100mm Takahashi at 225x (Nagler 2mm-4mm zoom). Cloud cover allowing, I get about 30 minutes of viewing of the super giant star as it transits from behind our neighbours roof and then is obscured by tree branches. 

The photo below shows how low this target is from here - around 14 degrees above a rather cluttered S horizon !

Dodging some wispy clouds here and there also managed a nice split of Zeta Herculis and the pleasing tiny "snowman" form of the sub-arc second pair of Lambda Cygnis.

This question has been asked before. Here is a link to the thread:

Celestron Luminos 31mm vs. Explore Scientific 82 Series 30mm - Discussions - Eyepieces - Stargazers Lounge

The questioner there had a dobsonian scope in mind but I suspect the ES 30 would be a better eyepiece in an SCT as well.

I'm happy to be corrected but I think there would be less coma showing in the F/6 scope than in the F/4. 

Edit: If I am corrected it will be by a coma corrector 😁

Variations on the "scope X on a Vixen" theme.

The mount under the Tak is the Celestron branded version of the Vixen GP.

The mount under the TMB/LZOS 130 is the Vixen GP-DX.

Caught with my 100mm frac tonight. Still hanging in there but it seems to have faded a little more - I reckon around magnitude 11.8 currently ?

It was discovered 1 month ago by the astronomer Koichi Itagaki.

8 minutes ago, John said:

Yay !!!

Just managed to split Antares with my 100mm Tak at 225x. Did a little sketch and the position angle corresponds almost exactly with the Stella Doppie position angle. The separation is 2.62 arc seconds and the component magnitudes vastly different at .96 for Antares and 5.4 for the grey-greenish tinted companion star. Plus it's very low down from here. First time with 100mm of aperture. Very chuffed 🙂

Good, steady seeing currently, helps a lot with this sort of thing !

Here is a blurry pic of my little sketch:

Yay !!!

Just managed to split Antares with my 100mm Tak at 225x. Did a little sketch and the position angle corresponds almost exactly with the Stella Doppie position angle. The separation is 2.62 arc seconds and the component magnitudes vastly different at .96 for Antares and 5.4 for the grey-greenish tinted companion star. Plus it's very low down from here. First time with 100mm of aperture. Very chuffed 🙂

Good, steady seeing currently, helps a lot with this sort of thing !

With the supernova SN 2013ixf still glowing at around magnitude 11.5 in Messier 101, I've been doing quite a bit of reading on these events and this one in particular.

SN 2013ixf is the closest supernova seen in the past 5 years although it is still ~20 million light years away. It is the 2nd closest in the past 10 years.

A couple of the sources that I found discussed the potential impact that such an event might have on nearby civilisations and a statistic that I saw repeated more than once was that significant impacts might be experienced by a civilisation existing within 160 light years of a Type II supernova event (SN 2013ixf has been classified as a type II supernova). 

What the term "significant impacts" means I've no idea and I suspect that the authors didn't know either but presumably more than just visual. I'm sure that stars which might be candidates to trigger such a catastrophic event are catalogued somewhere, although there is nothing we can do other than observe in any event. Betelgeuse is an often quoted candidate as a progenitor star for a supernova. It lies at a little more than 500 light years distant so perhaps we won't be affected much if it does go "pop" other than having some fascinating observing, imaging and research opportunities 🙂

Interestingly, the most recent bright supernova within our galaxy occurred in 1604. It was observed by Kepler and many others. Apparently the supernova outshone Jupiter for a while and was visible to the naked eye in twilight. That one occurred around 20,000 light years away so, other than the optical spectacle, of no risk to the human race.

Tycho Brahe's supernova, which seems to have been a type 1a, was observed in 1572 in Cassiopeia and is currently thought to have occurred at a distance of between 8,000 and 10,000 light years. That one was clearly visible to the naked eye in daylight for some months according to reports.

Going back to Betelgeuse, the giant star experienced an unusual dimming event in 2019 and, at that time, there was talk of whether this might signal the onset of a supernova event. Recent research links this dimming to a substantial mass ejection from the star but I think it is acknowledged that this red supergiant may well be in the latter phases of it's life, although these could well last many 1000's of years of course.

If alpha Orionis does do something spectacular then we will certainly get an amazing show to watch. Hopefully though, if the estimates are correct, we will survive to tell the tales to those that follow us 🙂

The "rule of thumb" that I use is that if an instrument has a desirable and valued characteristic, the manufacturer will be quick to mention it. 

So if it is not explicitly mentioned, it is safest to assume that it is not present.

Very interesting and there are quite a few points there that I can relate to so it has helped me think about future actions myself 🙂

No light at all is best if your targets are faint ones.

58 minutes ago, Mircea said:

John

I suggest to you to go deeper. I'm sure you will be able to see with the 120mm ED the two ''debillissima'' stars.

''Debillissima'' stars are located between the two pairs in Eps -12 Lyr. They are quite dim so better use high power.

I saw them with my 125mm F/ 6.9 Dobsonian and, recently, a forum fellow member saw them with a 114mm reflector.

 

Clear sky, Mircea

Thank you for the reminder about those fainter stars - I will look for them the next time I am out 🙂

I recently took my travel scope, a 70mm ED refractor, to the island of Jersey. The whole setup, including the mount and tripod, weighs under 5kg. Under the dark, transparent skies of the northern side of the island, where we were staying, the little scope did amazingly well even showing the supernova in the galaxy M 101 and a fair view of the core of that face on galaxy as well. The 70mm of aperture, under those skies, was doing about as well as 100-120mm does for me at home in terms of "going deep". 

I had a similar experience at one of the SGL star parties a few years ago when the 150mm scope that I took along was providing the sort of views that I normally needed 10-12 inches of aperture to get at home.

Now more aperture under really good skies scores even higher of course but there is a tipping point where, unless a really specialised design, simply getting a medium aperture scope out to those skies just becomes impractical. Where that tipping point is depends on individual factors, how much effort you can expend and how much access you have to specialist scope designs I guess.

For me, the scope must not become any sort of inconvenience, must be "off the shelf" and just needs to become part of the regular luggage.

Others though, will go to much greater lengths, Gary Seronik, for example:

My 8-inch Travelscope - Gary Seronik

With a few notable exceptions, many targets we observe are faint, indistinct, subtle etc. While I have and will always stick with visual observing, I can quite understand why many turn to imaging or electronically enhanced observing to pursue their interests in astronomy.

Fortunately we have great forums such as SGL which cater for the myriad ways that people like to "do" astronomy 🙂

1 hour ago, JeremyS said:

I don’t think so Malcolm, though you could always try a filter. Paul Abel uses an 8-inch telescope, often unfiltered: https://britastro.org/observations/observation.php?id=20230614_160349_2da60f868f446e37

I was not using a filter last night. I should have tried my herschel wedge with the ND filter (temporarily) removed and also I have ND, O-III and other filters available. 

I get a bit stubborn sometimes though 🙄

Each time I observe Venus I think I am seeing some contrast variations across the cloud tops at times, and then they change, and then I see nothing for a bit. I'm probably being over-cautious about sketching what I see as being transitory stuff, possibly even due to "trying too hard" !

It was a similar situation when I eventually managed to see the Horsehead Nebula a few years back. Once I had a couple of sightings that I was confident about, I realised that I had probably seen it a few times in the past but didn't know that I was 🙄

We are learning all the time in this hobby 🙂

23 minutes ago, Mr Spock said:

I remember first splitting them some 50 years ago with my 60mm f15 Prinz 550. The eyepiece I probably would have used was a 6mm Kellner at x150. I did have a 4mm orthoscopic, which while sharp , was very dim. I still have those eyepieces.

I still go back to it all these years later. 

Albireo in Leo was my first ever double star and that was with my old Tasco 60mm F/13.3. 🙂

I probably thought that exotica like the "double double" was beyond me and my little scope back then 🙄

Mind you, the wobbly tripods that such scopes came with did not help get the best out of them. Put these old long refractors on a decent mount and it's surprising how well they can do, as people are finding out 👍

1 hour ago, mikeDnight said:

Some eyepieces such as Naglers can add a yellow colour tone, but it could also be atmospheric. At times I've seen Venus display a nicotine yellow tinge when using my FC100DC, then on another night while using the same scope it's appeared silver white.  It has so far appeared white in my DZ, and in my FS128.

Venus looked fairly "white" this evening with my ED120. I used Tak TOE 4mm and Pentax XW 5mm eyepieces. 

1 minute ago, MalcolmM said:

I wonder is the big aperture of the 120 collecting too much light? Is it possible to have too much light?

Malcolm 

I've wondered that with Venus at times as well Malcolm. 

I'll try my little 70mm ED on it again very soon and see how that does. 

I also think some peoples eyes are better suited to picking up these very subtle contrast variations. Maybe my observing strengths lie elsewhere 🙂

Nice sketches and observations though. Prompted me to have another good look at our "sister" planet, which is nice on a warm evening 🙂

I'm having some fun on this warm evening comparing the views of Epsilon Lyrae with 3 apertures:

- 120mm F/7.5 ED doublet (Skywatcher ED120)

- 70mm F/6 ED doublet (Altair Starwave 70 ED)

- 52mm F/17.3 ED doublet (stopped down ED120)

The ED120 makes the split of both star pairs easily of course. The lowest magnification that clearly showed 2 separated pairs tonight was 70x.

The 70mm ED gets both pairs clearly split at 100x and up. Even looked decently sharp, though dimmer, at 200x.

The 52mm ED, rather surprisingly, also managed to split both pairs. Somewhat dimmer than the 70mm and I needed 115x to be sure that I was seeing 4 separate stars but I feel confident that the split of both pairs was made.

Not very scientific but fun all the same 🙂

Interesting thread 🙂

When it's darker I might have a look at this one myself with my ED120.

Stellarium is still showing it as being around 15th magnitude but Heavens Above has it at 10.3. 

Interesting sketches Malcolm 🙂

I may have seen some vague markings with my ED120, also with the TOE 4mm and later the Pentax XW 5mm (seeing was not so good here) but nothing that I could capture using a pencil and paper !

Thanks Don 

I'm not a glasses wearer when observing so ER , as long as it's reasonably comfortable, is not a critical issue.

Other feedback very welcome 😃