Stu

1 minute ago, Carbon Brush said:

We can all discuss these differences and appreciate how things change with latitude. But not everyone is like this.

On holidays near the equator....
I have immediately noticed how late afternoon the sun descends almost vertically to the sea. No scraping the horizon!
Darkness falls very quickly.
The sun ascends on one side of island, climbs vertically overhead and descends on the other side of the island.
None of the other (northern hemisphere) visitors I spoke to had noticed any of this. They just moved loungers to sun/shade as necessary.

Again on a near equator holiday. Where are the recognisable (northern hemisphere) stars? 
Let me locate Polaris to get started. Drat it is scraping the horizon. No way can I make it out.
Never mind. Look the other way (south) and enjoy the (never seen before) sights😁.
Again I was on my own noticing this. It was an island with little light pollution.

In Egypt on a night dive away from built up areas I remember orange skyglow from a town around 50 miles away.
I also remember how it suddenly got very dark when the (near full) moon dropped behind a big hill.
That has to be the measure of a clear sky. Again nobody else noticed.

Apologies for the ramble.

 

Yes, the speed it gets dark at those latitudes is very noticeable.

1 hour ago, Ags said:

I am thinking of a move to Kalamata, Greece, next year. It's not the equator but there is astro dark all year round.

I’ve often been disappointed with the transparency when I’ve been to places in the Med. Often it can be very hazy as pollution gets trapped down low. I guess exact location, winds and whether there has been recent rain all affect that, and I have had some excellent views but not always the case.

I thought I would post these up after some discussion on the thread about what people do during the ‘off season’.

I wanted to show what happens at the North Pole and Equator as the two extremes, unfortunately Clear Outside won’t go above 80 degrees N but it still illustrates the point.

So, from South to North…

Equator:

Crewkerne (My house 😊):

John O’Groats

80 degrees N:

So, I think I’ll move to the Equator! Fab views of all though MW objects and consistent night time length through the year 👍

The idea is to keep the eyepiece, objective or front plate JUST above the dew point, not to have it toasting away 😉. I agree with using them sparingly and on lowest setting to keep the dew away, but there are nights when the option is dew straps or pack away, so dew straps it is.

This little gem just turned up courtesy of @John. Looking forward to giving it a go. Hopefully might have a chance to compare with the 22mm Type 4 Nag, but that depends on the weather and when it sells. I hope I don’t regret the change, but doubt I will. This is either my second or third, I can’t remember 🤣🤣

2 hours ago, Richard N said:

It’s a good place to discuss clouds with geographically similarly challenged folks. 

There is a certain irony that members of the other forum actually see stars but the name implies otherwise, and this forum implies we do, but we don’t 🤪🤣

I would agree for visual, no need for Polaris, just setup North and level and that’s good enough. Option 1 for those Southern views.

If you need to reach other targets, it is quite possible to set the tripod up so its top is level on a sloping lawn, I do it quite regularly, that’s why tripod have adjusting legs 😉

Excellent sketch, really not easy to do. 

Yes, a quick google shows plenty of references to it working well. Sounds like a good combo 

17 minutes ago, seven_legs said:

Anyone?

Patience young grasshopper 🦗…. Someone will be along soon I’m sure 👍 

6 hours ago, Flame Nebula said:

O-III and UHC filter can enhance certain objects like nebula and planetary nebula

They certainly can. It is specifically emission nebulae (and planetary nebulae) which are enhanced as the emit light at specific frequencies so that filters can be produced which just allow these frequencies to pass, blocking out most of the rest. This does dim the image a bit, but increases contrast by increasing the difference in brightness between background and target. They still perform best under dark skies and with good dark adaptation but will allow views of some objects under relatively light polluted skies.

Reflection nebulae, and galaxies generally don’t benefit from filters as their light is broadband in nature so a filter just decreases the brightness of the whole image.

Don’t listen to the ‘you can only use them in 8” or larger scopes’ comments, they are not true. Yes, you do need some dark adaptation and dark skies but filtering can give amazing views of some objects like the Veil in 4” scopes, smaller even.

Actually, you haven’t talked about a 4” scope as far as I recall. If the same question was asked about 8” vs 4” you could add wider files views to the list. If you stick a 31mm Nagler in a Starfield 102mm you get a 3.5 degree field, enough for the whole Veil just about, whereas an 8” gives just over 2.1 degrees.

2 minutes ago, vlaiv said:

Depends on where you put observer.

If you stand on earth - then earth is moving with 0 units of speed relative to you and thus star A must move to the left and star B must move to the right.

For some external observer, standing near star C - it can indeed appear that all three are moving to the left or to the right or some other combination - because motion is relative to the observer.

Did I pass the test then Vlad?? 🤞🤞

@Flame Nebula bear in mind there may be a degree of ‘response fatigue’ going on as you have posted many questions, quite a few of them overlapping.

I didn’t interpret your post as anything disingenuine if that helps, it seemed quite clear. Luckily you all seem to have played nicely and sorted it yourselves, so thank you for that from a moderator perspective 🙏🙏

I have an FS128 and an 8” f8 dob. I think doubles are probably the main area where the frac probably shows things better than the newt due to the crisp round star shapes it produces. I probably find E & F in the trap easier in the frac, even things like the Double Double are generally cleaner splits. The frac does also show lovely contrast so competes fairly well but generally won’t show anything the newt won’t although perhaps some planetary and lunar detail can be better at times.

Did I mention getting some miles under your belt before ? 😉😉

Anyway, you are a space traveller, shouldn’t you know this stuff already 😉😉🤣🤣

15 minutes ago, Space Traveller said:

Sure they are moving away from us but in which direction.

Based on the basic diagram is Star A moving to the right and Star B moving to the left.

Consider this, Star B is moving to the right at a speed of 6 units.  The earth is moving to the right at a speed of 4 units and Star A is also moving to the right at a speed of 2 units, thus the stars show a Red-Shift.

However when we observe the stars, we are studying them from what I would describe as 'Thumb-Tack Earth', and there is nothing we can do about it.

Everything has to be based on a frame of reference I think, as there are no fixed points in space. From Earth, the would be moving away (simplistically left and right in your diagram), but from another frame of reference they could all be moving right at different speeds, both could be correct.

I’m sure someone far more intelligent will be along to help soon, where is @vlaiv when you need him 😉

6 hours ago, Stuart1971 said:

😂😂 no we won’t…it wouldn’t be around Yeovil anyway, looking more like Wells, or Shepton Mallet…👍🏻

Wells is lovely, not so familiar with Shepton Mallet as haven’t been there for years but sure it is nice.

7 hours ago, Elp said:

the larger the aperture and hence increased focal lengths don't the stars get ever so slightly bigger

Actually the opposite is true. As aperture increases, airy disk size decreases so stars appear smaller and finer detail can be resolved. This does however assume excellent seeing. You can see this effect in reverse when observing double stars through a small apo refractor. The small aperture gives large airy disk sizes which are easily seen even in average seeing and at more modest powers, so the effect is a very beautiful ‘bullseyes on velvet’ which is very aesthetically pleasing. With a large scope, the airy disks are much smaller and require higher power/better seeing to reveal themselves; often they are masked by poorer seeing so you end up just seeing scruffy stars which aren’t as nice to view, unless the seeing is excellent.

2 hours ago, Stuart1971 said:

Hmmm, and here are us looking at moving to Somerset…in the next 6 months…😮

Don’t let one idiot put you off! 👍

2 hours ago, dweller25 said:

Here are my drawings of Hesiodus an hour apart showing the increasing ray phenomenon.

It was great to get out with the scope again after weeks of bad weather.

Big thanks to @Nyctimene for flagging this up 🙂👍

 

Very nice! I caught it looking similar to your 20.40 sketch.

Someone being daft near Yeovil, not far from me. Reiterates that care is needed when using these devices anywhere with planes nearby though this person was obviously particularly stupid/malicious.

Somerset man jailed after shining laser at passenger plane https://www.bbc.co.uk/news/uk-england-somerset-68838349

13 minutes ago, Captain Scarlet said:

Yippee I got it! fast-moving cloud with a good few gaps. I used my 88mm Kowa spotting scope with Delos 4.5 inserted giving 113x. Awkward angle of course but once seen it leapt out. Very pleased.

Magnus

 

Astronomia postulat adlatum as per the WAG motto 👍👍

42 minutes ago, mikeDnight said:

I managed to spend an hour or so admiring the terminator tonight, despite not feeling too well after some rat bag gave me covid.  Anyhow, I decided to try using a 1.7X gpc in my binoviewer and a 2X Barlow in my diagonal. Not certain of the magnifications, but the views were gorgeous and far more detailed that the attached hand held phone pic's. Using my 35mm Ultima's and 25mm Parks Gold eyepieces,  the eye relief was very comfortable and would be great foe eye glass wearers. Sitting back in my chair it was almost like watching TV, or looking through a spaceship window. The scope was a FS128. Some pics were taken in daylight so a bit pale.

Nice shots Mike, you caught the light ray across Hesiodus crater, did you spot it?

4 minutes ago, IB20 said:

Managed to grab a few iPhone snaps with the SM125. 

Excellent! Wish I had a bigger scope with me but glad I shoved the FC-76DCU in so I could have a chance of seeing it 

5 minutes ago, dweller25 said:

It’s clear here and stopped raining just in time 🤣😄🌝🤪🥳

I have been viewing/ drawing since 18:45, watching a fan shaped beam of light gradually getting longer, will post some drawings tomorrow…..

Excellent, better views than me by the sounds, nice one.

Remarkably I managed to see this through the little 76mm. Not the clearest view as I was cloud dodging, but clear enough for me to be certain. Just had to drag a wet scope in from an unexpected shower, fortunately scope and eyepiece was capped although the finder is a little damp!