Nice hour or so...

[Xgaze]

Hi all,

Set up in the car park behind my house. Not a bad spot, away from houses, good views from NE around to the SW. North/Northwest blocked by our large Hawthorne. 

Started with a lovely few minutes admiring Saturn. Then up and tried to find some DSO's first attempt at M57 ring nebula but couldn't locate. The moon was very bright, too bright to view - wanted to maintain my adapted eye's!

Had a mess around with my 32m plossil what fun that is, not nearly as good as the Exmoor Dark skies but a brilliant EP. Pointed it over to the Mirach star to find M31 Andromeda. Finding this with ease now, should have looked at more around that area but got distracted by, what I'm pretty sure was ISS flying past, managed to catch it on the EP but was too quick for me to focus. A little annoyed I'd now lost sight of the original target, I though I'd have another go at the Ring Nebula. So glad I did! Finding it fairly easy this time, I finally spotted the fuzzy donut shape and found it quite exhilarating! 

The dark patch in the middle of the nebula was quite evident with the stock 10m EP and, I have to say it again; the 8m BST didn't seem any better! Perhaps it is me, not getting used to it yet?

The more I looked, aiming the target to the top of the view, allowing it to move across the EP then a slight nudge of the DOB to keep in view, I was able to pick out more and more, sometimes looking away from the nebula using my peripheral vision allowed better details. No colour but what treat it was!

After failing on a couple more targets, I decided to have a good look at Jupiter which had now climbed high and bright. Comparing it between the stock 10m EP & 8m BST.  I did, this time find the BST had the edge however, because it doesn't have irate the "rubber ring" around the end, as the stock EP does, I found the BST harder to view as steady. Is the anything I can do about this? I know there is an adjustable threaded bit on the end of the BST, tried moving this out as far as possible and having a play but it just didn't give as steady a view as the stock EP. Although, when settled it did give a bit better detail of Jupiters banding. The moons also lovely, punchy spikes of light.

Great short session, really pleased!

[John]

Great report - nice to read

There is a nice galaxy right next to Mirach known as "Mirach's Ghost". It's NGC 404. Should be visible as a small pale misty circular patch of light in an 8 inch dob at around 150x or so.

It's just above Mirach, in the same field of view. Just below Mirach through a dob of course !

 

 

 

[Xgaze]

16 hours ago, John said:

Great report - nice to read

There is a nice galaxy right next to Mirach known as "Mirach's Ghost". It's NGC 404. Should be visible as a small pale misty circular patch of light in an 8 inch dob at around 150x or so.

It's just above Mirach, in the same field of view. Just below Mirach through a dob of course !

 

 

 

Thanks John,

Out on Exmoor again tonight a week's camping there. Hoping it's clear enough! 

Will check out Mirach's Ghost, thanks for the heads up!

Best,

T

[JamesF]

4 minutes ago, Xgaze said:

Out on Exmoor again tonight a week's camping there. Hoping it's clear enough! 

Tomorrow looks a bit "exciting" weather-wise   Mind you, they regularly forecast thunderstorms that then fail to arrive, so it could well turn out to be another sunny day...

James

[badhex]

Lovely report! Thanks for sharing. 

[Zermelo]

Nice write-up. I'm impressed that you managed to get good results on M57 with the stock 10mm, it's not usually that great - you have the Heritage 150, I think? At F/5 I usually find the BSTs are a noticeable improvement, though perhaps the stock EP with half the number of elements is transmitting a brighter image, and with a small object like a planetary, the performance close to the axis may be similar. I'm surprised that you don't find the guard on the BST to be adequate; I thought the travel was at least as great as the depth of the eyecup on the stock EP. I wonder if yours is sticking.

[Xgaze]

On 24/07/2021 at 14:48, Zermelo said:

Nice write-up. I'm impressed that you managed to get good results on M57 with the stock 10mm, it's not usually that great - you have the Heritage 150, I think? At F/5 I usually find the BSTs are a noticeable improvement, though perhaps the stock EP with half the number of elements is transmitting a brighter image, and with a small object like a planetary, the performance close to the axis may be similar. I'm surprised that you don't find the guard on the BST to be adequate; I thought the travel was at least as great as the depth of the eyecup on the stock EP. I wonder if yours is sticking.

Thanks Zermelo!

Yes, I have the SW 150 DOB.

I admit, I do need a bit more time with the BST. Perhaps having more time adjusting the eye relief will help, is this what you are calling "guard"? Is that the screw threaded end on the BST?

Apologies if I don't reply immediately, camping on Exmoor again! Hoping it's going to be clearer tonight!

Best,

T

[Zermelo]

1 hour ago, Xgaze said:

Perhaps having more time adjusting the eye relief will help, is this what you are calling "guard"? Is that the screw threaded end on the BST?

The eye relief is the distance between the outermost lens element of the eyepiece and the spot that you need to place your eyeball to see the image. A very small eye relief (e.g. 5mm) means that you have to put your eye very close when observing, and may make it impossible to use with eye glasses, if you wear them. On the other hand, a very large eye relief (which can be increased further if using a barlow) can make it difficult to keep your observing eye "floating" in the correct position. The Starguiders have a built-in "twist up eyecup" (that's what I shold have called it) that you can adjust to a position suitable for observing, i.e. you can place your eye socket gently against the cup and your eye will be more or less the correct distance. The cup can also help to keep out stray light from the outside. It performs the same function as the rubber eyecups on the stock eyepieces. They do not alter the eye relief of the eyepiece - that is determined by its internal design.

The eye relief for the BST 8mm is given as 16mm. I measured the total travel of the eyecup on my 8mm Starguider when fully twisted out - around 9.7mm. Then there is also a small distance between the eyecup end and the outer edge of the eye-lens, which I'm not going to put my callipers onto.

Hope you get some decent weather on Exmoor.

 

[Xgaze]

On 26/07/2021 at 12:16, Zermelo said:

The eye relief is the distance between the outermost lens element of the eyepiece and the spot that you need to place your eyeball to see the image. A very small eye relief (e.g. 5mm) means that you have to put your eye very close when observing, and may make it impossible to use with eye glasses, if you wear them. On the other hand, a very large eye relief (which can be increased further if using a barlow) can make it difficult to keep your observing eye "floating" in the correct position. The Starguiders have a built-in "twist up eyecup" (that's what I shold have called it) that you can adjust to a position suitable for observing, i.e. you can place your eye socket gently against the cup and your eye will be more or less the correct distance. The cup can also help to keep out stray light from the outside. It performs the same function as the rubber eyecups on the stock eyepieces. They do not alter the eye relief of the eyepiece - that is determined by its internal design.

The eye relief for the BST 8mm is given as 16mm. I measured the total travel of the eyecup on my 8mm Starguider when fully twisted out - around 9.7mm. Then there is also a small distance between the eyecup end and the outer edge of the eye-lens, which I'm not going to put my callipers onto.

Hope you get some decent weather on Exmoor.

 

Thanks for this, really useful and makes perfect sense. 

I will certainly have a play with the twist eyecup and see if it helps.

Six nights on Exmoor,  Alas, only last night offered the opportunity to see anything! Just managed to see M57 for a few minutes and show friends, which was nice.

On to the next session...

Regards,

Tony