What am I seeing?

[DamianL]

This is my first post having had my telescope for around 6 months which was swiftly accompanied by endless cloudy skies. 
 

I managed to get out for the first time this week and was checking out some of the brighter, bigger stars in the sky including Betelgeuse and Sirius, and when looking through my telescope once focussed I could see what looked like solar activity, it actually looked like a large dot of fire with shimmering ripples. 
 

Surely there is no way that a home telescope (8” Dob) would be viewing distant stars with that level of detail, so my question is what am I actually seeing and is it an indicator of something I need to tweak in my telescope perhaps with collimation or something?

[Swoop1]

Hi Damian and welcome to the forum.

If you were viewing the moon or a planet I would suspect you were seeing the result of moving air- atmospherics are very visible in solar system viewing. As you were viewing a star however, I'm not so sure. It could be that an aircraft flew across the star and you were seeing the result of the hot jet engine exhaust?

I am sure more knowledgeable forum members will be along soon with a more accurate explanation.

 

[RT65CB-SWL]

Hi @DamianL and welcome to SGL. 

Judging by your description, it sounds like it may need a collimation tweak. Very few reflectors are 100% collimated when you receive them. Due to shipping and handling they do loose it... a little.

Have you decided on what collimator to purchase? - If you go for a laser collimator then you will need to check it for collimation too, before initial use. There are YouTube video tutorials on how to do it.
Alternatively, there is the 'Cheshire' collimator or collimation cap and these require no pre-setup.

Stars [and planets] nearer the horizon will be difficult to get perfect views, as you are looking through a thicker portion [and dirty layers] of the Earth's turbulent atmosphere. Also if viewing/observing on concrete, tarmac, over rooftops, other buildings, etc., they will be releasing heat... so you will be seeing the thermals from them too! 

  

Edited January 29, 2022 by Philip R

[PeterStudz]

As suggested that could be the result of turbulence in the atmosphere - the jet stream, viewing over a building or something relatively warm, the lower the object in the sky then the worse it tends to be. 
 

Possibly tube currents too - how long was your telescope outside before you started viewing? I need to leave my 8 inch Dob outside for at least 30 mins, often 45 mins at this time of year when it’s cold, before it’s sufficiently cooled to allow stable views.  

[DamianL]

12 minutes ago, PeterStudz said:

As suggested that could be the result of turbulence in the atmosphere - the jet stream, viewing over a building or something relatively warm, the lower the object in the sky then the worse it tends to be. 
 

Possibly tube currents too - how long was your telescope outside before you started viewing? I need to leave my 8 inch Dob outside for at least 30 mins, often 45 mins at this time of year when it’s cold, before it’s sufficiently cooled to allow stable views.  

I had it outside all afternoon. I spent some time with light to make sure the finder scope was aligned and also did some rudimentary focus testing on distant objects.

I haven’t collimated it yet, but general focus seems OK and I’ve been a little scared of touching it, not least because the clear skies have been few and far between and I wouldn’t want to spend my entire day fixing what I’ve broken!

I do have some holiday this week so I plan to have a go at proper collimation then. Hopefully get the process down so I have no fears doing it before every session.

In the mean time I’ve found a video on YouTube here that shows the same thing that I was viewing through my scope, in case my description was a bit rubbish. I don’t know how to do timestamps in YouTube links, but 6 minutes in shows it pretty well. Ignore the fact that the channel is a little bit OTT aliens and fairies.

My collimator is a Cheshire, so no laser for me.

 

[PeterStudz]

16 minutes ago, DamianL said:

I had it outside all afternoon. I spent some time with light to make sure the finder scope was aligned and also did some rudimentary focus testing on distant objects.

I haven’t collimated it yet, but general focus seems OK and I’ve been a little scared of touching it, not least because the clear skies have been few and far between and I wouldn’t want to spend my entire day fixing what I’ve broken!

I do have some holiday this week so I plan to have a go at proper collimation then. Hopefully get the process down so I have no fears doing it before every session.

In the mean time I’ve found a video on YouTube here that shows the same thing that I was viewing through my scope, in case my description was a bit rubbish. I don’t know how to do timestamps in YouTube links, but 6 minutes in shows it pretty well. Ignore the fact that the channel is a little bit OTT aliens and fairies.

My collimator is a Cheshire, so no laser for me.

 

The video, at approx 6min in, is what I get from atmospheric turbulence, especially at high magnification. Often described as the “seeing”. 

[DamianL]

2 minutes ago, PeterStudz said:

The video, at approx 6min in, is what I get from atmospheric turbulence, especially at high magnification. Often described as the “seeing”. 

Thanks. Whilst I’ve always been passionate about space and our solar system in particular, I’m a complete novice when it comes to observing through powerful equipment like this. My only telescope prior was a cheap little Discovery Channel branded one from the Argos catalog when I was a kid.

Over Christmas I registered with our local astronomy club who have a dark site about 20 minutes from me with pads and an observatory. Between those guys, my growing library, and this forum I’m looking forward to a very educational year!

[PeterStudz]

No worries @DamianL. I’m certainly no expert so there could be something else.

It sounds like you are doing the right things. There’s much to learn in this hobby and my advice is to take your time, don’t give up (sometimes it can be frustrating) and apply plenty of patience. If it’s your cup of tea then observational astronomy can be very rewarding. And don’t be frightened to ask questions, however silly they might appear! Something that I’ve been guilty of in the past. 
 

[Louis D]

On 29/01/2022 at 08:07, DamianL said:

I don’t know how to do timestamps in YouTube links

It's pretty simple.  Just pause the video at the beginning of the section you want to highlight, right mouse click over the video, select the third option down (Copy video URL at current time), and paste that URL.  You could even edit your post above to fix this by clicking on the three dots at the far right of the gray bar with your user ID and post timestamp, selecting Edit at the bottom of the list of options, delete the original video inserted and paste in the corrected URL, and then fix up the text since you now know how to do all this. 😀

Edited January 31, 2022 by Louis D

[JOC]

Could it be the OP is viewing Sirius - the monster raving party star!  Which appears to move and fluctuate and appear larger that it is as it is viewed through a lot of atmosphere?

[AstroMuni]

On 29/01/2022 at 14:07, DamianL said:

In the mean time I’ve found a video on YouTube here that shows the same thing that I was viewing through my scope, in case my description was a bit rubbish. I don’t know how to do timestamps in YouTube links, but 6 minutes in shows it pretty well.

From your description it sounds like the effect of air turbulence as mentioned by others. And as you view stars such as Sirius, these are quite low near the horizon at the moment, so turbulence will be higher. And if its skirting above nearby rooftops that doesnt help either as the rooftops are giving off heatwaves.

If you could see faint rings in the view then its a case of poor focus.

Good luck with your new found interest. Your local club should help a lot.

Edited January 31, 2022 by AstroMuni

[Louis D]

Another diagnostic tip is to defocus the star and observe the undulations on a larger scale.  Put your hand in front of the objective and you should see heat waves emanating from it.  Remember, we're looking up through many miles of thick atmosphere that has all sorts of currents and bubbles in it.  It's one of the reasons professional observatories are placed high up on mountaintops that have fairly laminar airflow over them year-round.