jetstream

1 hour ago, bingevader said:

And for the statistically challenged amongst us!

Could we have a lay mans interpretation of what difference 0.4 of a Wave means, please? 👋

Lets ask an experienced observer- @John- I think you have used f4.7-f4.8 dobs and you own an f5.3. What is the difference with the 21E (or others) coma wise in these? The f4.8 comes in at 2.4 waves and the f5.3 at 1.9 waves for a difference of .5 waves.

Great report Stu!

F5 10"

F4.7 10"

37 minutes ago, Raph-in-the-sky said:

How big is the difference between f5 and f4.7?.... numbers seem to be close but I have no reference point

Mel comes through again... punch the numbers in and it will tell you the coma in rms waves, very interesting. Just go to "eyepieces" and the calculator will come up.

http://www.bbastrodesigns.com/NewtDesigner.html#is aperture king

Great report Damian, one of many I hope to read!

4 hours ago, wesdon1 said:

will i be able to see any Galaxies, Neb or DSO's in general?

Congrats for seeing M42, and the fact that you could means you should be able to see a few DSO from your site. Pick the brightest ones when they are high up- M31, M13,M81/M82 all come to mind with the VG 200mm reflector.

To see the ones listed I would try upping the mag a fair bit- what eyepieces do you own?filters?

51 minutes ago, Littleguy80 said:

Is there further nebulosity to see?

Keep looking......

More info...

http://www.astrosurf.com/zoll/images/G65_3__5_7.html

Hint: Sh2-94

In the 10" I felt something was there and the 15" confirmed it, this is pretty hard. Susan Young is s great observer and the picture is from her report. Here is the OIII response which helps us look in the right place....

http://sandandstars.co.za/2017/07/26/cygnus-other-snr/

Congrats Neil!

SH2-91 is not an easy target, ghostly in appearance and a worthy target for any scope. Did you see anything else in the area? there is another, tougher section that is visible

2 hours ago, Littleguy80 said:

My dark adaption seemed to have gone up a notch from the search for SH2-91.

It will for sure, but...

2 hours ago, Littleguy80 said:

a failed attempt at Stephan's quintet.

this is not surprising actually. If your like me then after concentrating on viewing very faint nebula my galaxy abilities are lacking. I noted this over and over and now when observing galaxies they will be the primary targets for the night- at the end of a session I might sky cruise nebula though.

Stephans Quintet is easier in a 10" than SH2-91 for me- I can get 3 very faint overlapping cores with the 10" and an ortho for best views.

Oh and I forgot- did you look for hints of a detached patch right off the tip of the Easter Veil, near the one you saw? Again congrats as these features are only seen in top notch images....

Interestingly enough my 200mm f3.8 will show pink under the wings of M42 and with a dazzling mottled green core all in a small package @ 36-44x. The dust lanes in M31 are also very contrasted against the bright galaxy glow.

I'm not sure where to put this thread so mods move it if need be, thanks.

Mel Bartels observes very faint, very large objects effectively using some rather unique reflectors, unique in the sense of their f ratio and size. Entendue or light through put in telescopes is an interesting theory which might ruffle the feathers of those who think detectable contrast is only linked to object size (in the eyepiece) and eye illumination (exit pupil).

I have a 200mm f3.8 and can say it does show some things better than other telescopes like the IFN near Vega.

I hope some good discussion will result from posting this link,Gerry

http://www.bbastrodesigns.com/HET.html

6 minutes ago, Piero said:

No, I've never found a collimation shift during a session, but I like to check just to be sure. It takes 1 minute, really. 

I do have a shift of a couple of mm when I rack the focuser in and out, though. To counteract this, I collimate the focuser axial alignment with the drawtube racked out about as much as the travel needed by my eyepieces in order to reach focus. Doing so, the miscollimation shift is compromised. 

Will you get a coma corrector one day? 

Yes I might get one but I'm not sure of the effect on DSO... some say it should increase contrast, which could be true if the coma reducing effect increases contrast greater than any potential loss from all the extra glass etc. Could be a costly experiment...

In these focusers, even with tight fitting lasers and sight tubes leaving the focuser thumbscrews loose show how much the laser dot can move if touched...I always center my laser on the secondary with the same thumbscrew tightened first- and then tighten the same thumbscrew first with the eyepiece.

Glatters parallizer can take care of part of this, but where does it end lol!

I'm going to start a thread on "entendue", you might find this interesting, if not controversial.

3 hours ago, Piero said:

time to time checks are done only on the 1mm aperture stop, though.

Do you find that collimation moves during a session?

On 22/08/2019 at 17:04, Piero said:

but also whether I'm using my instrument at its highest potential. 

Interesting formulas Piero and the coma free area is what it is regardless of how its calculated.  I would be very interested to see if your collimation method would result in all the reflections being stacked in a dual pupil autocollimator....

from what I understand the most accurate collimation results when all tools are in agreement, including the DP autocollimator- for us amateurs anyway.

On 22/08/2019 at 10:11, Trentend said:

Wonder if this explains the poor views?

I tested my Moonlight with a weight simulating the Binotron 27's and 2 Docter 12.5mm eyepieces. This allowed my to watch the Catseye cheshire and Glatters laser as I racked the focuser in and out. After about 1/2 travel miscollimation began, enough to damage views.

What I did then is adjust the extension tube to allow 1.3x and 2.3x (Powerswitch) focus in the first third of focuser travel. I will then pull the bino out to focus for 3x with the focuser at half travel or less.

I've heard new Feathertouch's might sag more than the Moonlight and would like confirmation (or not) actually. I use the 45mm OCS with the bino's.

Edit: Oops forgot you had an aluminum OOUK tube- I tested my VX10 and it was the tube that flexed, lots. I have a different stock OOUK focuser than yours though. @faulksy had to reinforce his VX14 if I remember, to help with the issue. Mine flexes so much I don't binoview with it.

21 minutes ago, Littleguy80 said:

 Is it the small section just above the Eastern Veil in the sketch?

Yes it is right at the top of the left side of the sketch above and close to the Eastern Veil. If M8 is not naked eye you might have extinction further up as well and with this there is very limited chances of seeing this faint patch. There is also another very faint detached patch right off the very tip of the Eastern Veil that is not shown, difficult as well.

The 24" shows more nebulosity than the sketch but differently, more delicate perhaps and more detailed.

Eagerly waiting reports!

35 minutes ago, Littleguy80 said:

Thanks Gerry. That sketch is stunning!! 25” at F2.8!!! What a scope that must be!

There is a little challenge in this sketch for you

Way before this sketch, a couple of years ago I reported seeing very very faint nebulosity near the end of the Eastern Veil, @Stu helped me with confirmation - your 10" will show this area as extremely faint, almost as a ghostly line- right at the limits of your scope.

I'm so happy Mel has it in this sketch! It will not show like this, but its there. Its the detached patch at the very top of the Eastern Veil in the sketch- give it a try!!

Great obs of the Lagoon Neil, more and more will reveal itself top you. Can you see it naked eye?

1 hour ago, Littleguy80 said:

Seeing the Veil in a single FOV under dark skies has been on my wish list for awhile. I was very, VERY pleased to finally achieve this.

Awesome report Neil!

Check out this sketch of Mel Bartels... a 25" f2.8- holy! Man he pulls out details and find myself chasing them- and most always see the features.

1 hour ago, Ships and Stars said:

Sounds wonderful, I wish I lived in a dark sky area in the countryside (or wilderness for that matter). It's nice having a shop around the corner, but I would certainly survive if it was 20 miles away. My current 'dream' (they change frequently) is to open a dark sky campground in the Highlands in a remote area near a loch or seaside, so I could combine kayak/paddleboard hire with well-spaced apart camping areas and little to no light pollution...

It would stay open year-round as well. Nearly every campground here shuts down after Sep/Oct at the latest, barring a very small number of exceptions.

Nice to dream, that's how I managed to do lots of different things in life so far!

Local weather forecast is looking up as well for next week. Fingers crossed as always.

Clear skies!

That sounds fantastic, and if you could exist comfortably go for it!  Why do the campgrounds shut down early? Is it cold there? Scotland sounds VG.

Perfect!

Maybe I should up the mag for these things? I must try some different things I think, maybe start with the zoom and fine tune with orthos or something.

@Stu question- in the center of M31's core there is a tight point of light- is this a glob I wonder? straight smack in the middle. Any other members opinion welcome too

4 hours ago, clarkpm4242 said:

I observed the Bubble many times when I had an 18" Obsession.  Usually from mag. 6.5 skies.

Very, very rarely did I get a 'bubble', most of the time just a short arc.

 

This has charts for the painstaking starhopping required

https://ned.ipac.caltech.edu/level5/ANDROMEDA_Atlas/frames.html

Another useful link.  Think I found about 2 dozen.  Was a bit obsessive though

https://www.astronomy-mall.com/Adventures.In.Deep.Space/gcm31.htm

Good hunting!

Cheers

Paul

Thanks Paul, last night went 6.4 NELM using 20 Umi so not the best really but nice. This is great info and is much appreciated- 2 dozen in there?! I never knew this- can't wait so see some of these suckers lol! I took a quick peak last night but between the poor trans ans emerging moon I called it quits then.

7 hours ago, Stu said:

Great report Gerry, it's amazing what you are picking up even though conditions are not that good.

Excellent suggestion from Mark, that would be a good challenge. G1 is brightest I think, mag 13.7 and quite a distance from the core, a few others below mag 15 that I could see here.

Thanks Stu!

The 15" gets G1-I guess its called and I truly hope I can get more.

As far as the Bubble size, thanks for that info too. I just used the TFOV with the Lunt as a rough guide as it was a bit smaller than the field of it, so smaller than .8deg. Observing planetaries with this thing is is making me seek them out now! I never thought there would be so many with detail such as the Magic Carpet, Catseye and now the Bowtie, seems I like these now lol!

7 hours ago, mdstuart said:

That sounds amazing. I have seen the members of the quintet (just) with my 16 inch but never the bubble nebula!

That 24 inch scope is certainly performing. 

See how many globular clusters of M31 you can pick up.

Mark

Thanks Mark, the new scope sure does work well. With the 15" Stephans Quintet was a triplet with a possible 4th. What this 24" does is open the object right up- great separation and even separation between the cores of the harder ones, they are connected by a faint glow. Honestly its no talent of mine to see it like this, any half experienced, dark adapted observer would see it easily and in direct vision with this scope.

The 15" shows the Bubble, but not like this at all. This is what surprised me so much.

I have seen that large glob at the end of M31's arm with the 15", can't remember the name but I hope theres more in there!

I love this scope!