Lyra to Cassiopeia

[orions_boot]

Last week I received the 10" Bresser dob and since then I have basically been messing around with it when the sky was clear.  Trying to learn how the view matched the finders, which way to move what and by how much.

The last few nights I had a good look at Mars and Saturn as reported elsewhere.  Not that it fits in with this report but I have seen the southern polar cap on Mars at x360 mag and Saturn clearly separated from its rings.

Last night I devised a plan for tonight around Lyra given that it is quite small and in a good position for me in a dark patch and not directly above me.

I started at Epsilon Lyrae however I didn't split them again, I was mainly orientating my self form Vega.  This was split in 10x50s already and at 35mm in the scope I didn't get much from it.  I then tracked down to Beta Lyrae and found that double to check I was on track as this was barely naked eye visible.  

From there I scanned across with the 35mm Aero and found a faint smudge of M57.  After trying multiple times to change EP without moving the scope I got the zoom in.  Despite the masses of light pollution and reflecting from lower clouds I found clearly make out the ring as a grey circle and dark centre.  Zooming in didn't doo much except make it more blurred.  I tried an oiii filter and possibly the contrast increased but didn't make the difference it does to M42.

I then went for M56 switching to the 35mm.  Sure enough I found it again incredibly faint more like looking at Andromeda core through binoculars.  I then tried to switch for the zoom and the scope moved 2mm too far and I never found it again.  I had a look around Cygnus for M29.  Book says it is 'a few bright stars in a rich field'.  I was sure I had seen it but having looked at some sketches the shape is a bit different. 

I then moved to Cassiopeia as this was now darker and and in a better position.  Overall I  struggled given how close some of the things are to each other.  NGC 663 I am happy with.  Two 'clouds' of stars separated by space albeit fairly faint there was certainly 30-40 stars visible.  NGC654 not convinced I found it.  M103 I saw as a bright red star and blue stars in a line and didn't realise that was it until I looked at some pictures later.  I will be revisiting that with a zoom as it fairly bright for me.  NGC457 was excellent even the wife was impressed and most of the time she can't even see what I am looking at.  Two big bright eyes and very obvious arms and legs.  Can't count how many stars.

If anyone has read as far as this and is still learning like me then the learning is 1) start wide 2) find a way to change EP without the scope moving 3) I don't know what I am looking at so when planning a session have a look at some sketches first 4) for some reason I can see the secondary mirror shadows in the 35mm EP so have contacted supplier for advice 5) quick finder outer ring view is almost the same as the 35mm field of view.

[Paz]

That's a good collection of objects observed, there's a lot to see in that part of the sky.

[Mr Spock]

Sounds like a really good session.

It's worth noting it's normal for low power eyepieces to show the secondary in a Newtonian. I used to have a 250mm Skywatcher and that was the same with my 42mm eyepiece. Just move to a higher power.

[Nik271]

6 hours ago, Mr Spock said:

Sounds like a really good session.

It's worth noting it's normal for low power eyepieces to show the secondary in a Newtonian. I used to have a 250mm Skywatcher and that was the same with my 42mm eyepiece. Just move to a higher power.

I agree with Mr. Spock this is not a fault of the scope, in fact the secondary is visible at low powers in all obstructed scopes. The reason is the large exit pupil: In a 35mm EP the exit pupil is massive 7mm of which the secondary is close to 2mm, so you can easily see it in daylight. In fact during the day the eye pupil is smaller than 2mm so you can get a blackout if you eye is positioned dead center on the EP axis.

This also shows that to get the full benefit of the full aperture at such low magnification you need to be fully dark adapted so your eye pupil can  cover as much of the 7mm light cone as possible.

This looks like a great versatile scope! My largest one is only a 7inch MakCass, I'm getting aperture fever  

Nik

[RobertI]

Lovely report, NGC457 is one of my favourites, must have looked great through a 10” Dob. 
 

52 minutes ago, Nik271 said:

I agree with Mr. Spock this is not a fault of the scope, in fact the secondary is visible at low powers in all obstructed scopes. The reason is the large exit pupil: In a 35mm EP the exit pupil is massive 7mm of which the secondary is close to 2mm, so you can easily see it in daylight. In fact during the day the eye pupil is smaller than 2mm so you can get a blackout if you eye is positioned dead center on the EP axis.

Nice explanation. As you get older your pupil’s dilation decreases so some people may only be reaching 5 - 6mm eye pupil diameter, making the situation even worse! 

[orions_boot]

13 hours ago, RobertI said:

Lovely report, NGC457 is one of my favourites, must have looked great through a 10” Dob. 

Looked exactly E.T. !  I can't wait to look again.

14 hours ago, Nik271 said:

This also shows that to get the full benefit of the full aperture at such low magnification you need to be fully dark adapted so your eye pupil can  cover as much of the 7mm light cone as possible.

Thanks for all input including this which summarises it all.  ON reflection it was heavily light polluted and thinking back a week when it was dark I didn't see this shadow.

 

Thanks for commenting on my report.  I don't have much else to contribute to this community as I don't know enough but at the least I can submit reports, and it helps me log what I have seen and complete my research