Sigma Ori

[todd8137]

Hi all 

After setting up and have in Sigma Ori on my list I checked the scope and it was ready to go after a two hour cool down ,I flipped the telrad on and aimed at Polaris with a 10mm .the view was brill ,still I made a small mirror adjustment and there they both was 

i then went to sigma Ori and was not disappointed  I could see all  with no problems my drawing does not do it justice ,the 32 mm gave the best view but for the pencils I tried the 12mm  to get closer  some looked very blue tonight which amazed  me because never seen colour .i did split many doubles but the cold got me after 35 minutes not only that the tea I knocked over was froze solid on the floor 

EDIT  

so after much discussion I may not have split parts A/B there was two of us but with the looks of it  it did not happen I and anoth did see what I thought may have been it sorry for any confusion 

I do intend getting to the dark site with said scope to confirm this but it's tough 

clear skies always 

Pat

[NGC 1502]

Hi Pat, well done.   There is another Struve multiple star in both of your sketches, so two for the price of one !

I love double/multiple stars, the whole sky is stuffed with them and they can be well seen through heavy light pollution or when the moon is up.

Regards, Ed.

[todd8137]

12 minutes ago, NGC 1502 said:

Hi Pat, well done.   There is another Struve multiple star in both of your sketches, so two for the price of one !

I love double/multiple stars, the whole sky is stuffed with them and they can be well seen through heavy light pollution or when the moon is up.

Regards, Ed.

yes not hard to see at all but just seeing them I did what I thought where other doubles, there was a lot in the fov going of with background stars ,

pat

 

[laudropb]

Very nice sketch and capture.

[Stu]

Very nice sketch Pat, but I thought there were only 4 stars visible in Sigma Orionis? I'm a bit confused ?

[todd8137]

44 minutes ago, Stu said:

Very nice sketch Pat, but I thought there were only 4 stars visible in Sigma Orionis? I'm a bit confused ?

There is by there is ab and c,d e,I draw ab to far apart 

[Stu]

Did you split AB?

[todd8137]

Quote

Hi and welcome f

17 minutes ago, Stu said:

Did you split AB?

No it was more of a bulge on the main ,I new it was there as there was two diffraction patterns ,I drew this  couple of years ago ,the one on the left is from two years ago 

 

[Stu]

1 hour ago, todd8137 said:

 

I mean no disrespect, but the AB pair are only 0.25" apart, and as far as I'm aware not possible to split with amateur scopes. This is especially so at x36 magnification so perhaps it was just the effects of seeing disrupting the diffraction rings that you saw?

[lunator]

Stu

It may be possible to see AB in the 16" as they only about 1 mag difference and the Dawes limit for the scope is 0.29". You need excellent seeing though.

Pat what mag does the 12mm give you?

Cheers

Ian

[Stu]

1 minute ago, lunator said:

Stu

It may be possible to see AB in the 16" as they only about 1 mag difference and the Dawes limit for the scope is 0.29". You need excellent seeing though.

Pat what mag does the 12mm give you?

Cheers

Ian

Perhaps, but not at x36 surely?

[lunator]

Stu

I was thinking more of the 12mm  

I am a bit confused by the magnification as the 32x36 makes for a focal length of 1152mm which is very short for 16"/400mm scope.

Cheers

Ian

[Stu]

5 minutes ago, lunator said:

Stu

I was thinking more of the 12mm  

I am a bit confused by the magnification as the 32x36 makes for a focal length of 1152mm which is very short for 16"/400mm scope.

Cheers

Ian

Understood, but the sketch with the 32mm at apparently x36 shows 5 stars with clear separations. Everything I read says that AB is not possible to split, but at best I would expect an elongated star at very high mag, not a clean split at x36?

[lunator]

Stu

I agree  x36 is a big ask.

Pat can you check the details?

Cheers

Ian

[Stu]

20 minutes ago, lunator said:

Stu

I was thinking more of the 12mm  

I am a bit confused by the magnification as the 32x36 makes for a focal length of 1152mm which is very short for 16"/400mm scope.

Cheers

Ian

The scope looks like it's probably f4.5, so more like 1800mm which would be x56, still nowhere near enough to split a binary that tight.

[todd8137]

37 minutes ago, lunator said:

Stu

It may be possible to see AB in the 16" as they only about 1 mag difference and the Dawes limit for the scope is 0.29". You need excellent seeing though.

Pat what mag does the 12mm give you?

Cheers

Ian

The twelve gives  x97  

[todd8137]

The focal lenght is 1,171 mm 

[Stu]

7 minutes ago, todd8137 said:

The focal lenght is 1,171 mm 

I'm sorry Pat but that doesn't seem right. That makes it f2.9, incredibly fast and the scope physically looks more like the 16" f4.5 I used to own. Can you confirm?

Do you use a coma corrector?

[todd8137]

so if I measure from the mirror to the ep it's 

[todd8137]

This is the exact mirror set I brought  from these 

[Stu]

13 minutes ago, todd8137 said:

This is the exact mirror set I brought  from these 

Well I was pretty close, wasn't I? f4.4 and I guessed f4.5

So focal length is 1776mm, giving you x55 with the 32mm and x148 with the 12mm

Can you confirm what you saw with both? As said, from what I've read, AB is a really tight double, not resolvable with most scopes and even then it would require high power. You've shown (I think, if I'm reading the sketch right) that you had separation on them but I'm not sure that's possible.

Im only asking for the sake of clarity and for my understanding.

Cheers,

Stu

[todd8137]

52 minutes ago, Stu said:

I'm sorry Pat but that doesn't seem right. That makes it f2.9, incredibly fast and the scope physically looks more like the 16" f4.5 I used to own. Can you confirm?

Do you use a coma corrector?

 

[todd8137]

5 minutes ago, Stu said:

Well I was pretty close, wasn't I? f4.4 and I guessed f4.5

So focal length is 1776mm, giving you x55 with the 32mm and x148 with the 12mm

Can you confirm what you saw with both? As said, from what I've read, AB is a really tight double, not resolvable with most scopes and even then it would require high power. You've shown (I think, if I'm reading the sketch right) that you had separation on them but I'm not sure that's possible.

Im only asking for the sake of clarity and for my understanding.

Cheers,

Stu

I  think so there was two of us  it looked more like this most of the time am I split it but  I could be wrong a may have put it in the wrong spot but we both said we saw more of it sticking out like in the pic below 

[lunator]

Hi Pat

thanks for the clarification.

I have split at or below the Dawes limit on my 8" and 10" scopes. I have checked back through my notes and the best I managed was 0.7" at x180, mostly it takes x200 mag plus.

I think you may have seen the elongation in the 12mm but it would be tricky in the 32mm as i think the size of the Airy disc would swamp the secondary.

Cheers

Ian

 

 

[todd8137]

Will soon find out next clear night I have split doubles before all I view mainly is doubles binary so forth ,next time I must get my freind to confirm before posting next time 

pat