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markclaire50

Sirius B and E/F stars - what does it take!?

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5 hours ago, John said:

If you switch the mount drive off, the pup star follows Sirius A as it drifts across the field of view. So the pup is to the east of the primary star.

The pup gleams through the flare that is coming from the primary star as a tiny point of light. Its often intermittently seen.

 

 

 

Hi John. That's where I was looking. Chris' photo shows it to the west though. I've just checked on Google and indeed for a mak, the image is reversed, so it would be in front of star. For a newt, it would follow. So, I was focusing my eyes in the wrong place. Not that anything leaped out from either side! 

Edited by markclaire50

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4 minutes ago, AstroCiaran123 said:

Have spotted the E star on occasion with my OOUk 8" newt.  Observing from Belfast so takes a special night of seeing. First time I spotted it I put it down to poor optics and recollimated !

 

Hi Astro

Thanks. What is interesting is that people with 6" newts and 4" fracs seem to get e  and f whereas observers have reported no sighting with 14" and 16" sct! I've been toying with idea of the 8 or 10 " OOuk newts. But I'm worried about the bulk. I was thinking of the 9.25" sct or 180 mm mak. I would hope either of these would see E and F! The pup seems a tough one for even 10". 

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11 minutes ago, markclaire50 said:

Hi John. That's where I was looking. Chris' photo shows it to the west though.. 

That is the orientation as seen in the Mak, which shows E at 90 degrees and W at 270 degrees, as they should be on a compass. As John says, the Pup drifts behind Sirius when the drive is not running and is therefore nearly true E of Sirius.

Chris

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5 minutes ago, chiltonstar said:

That is the orientation as seen in the Mak, which shows E at 90 degrees and W at 270 degrees, as they should be on a compass. As John says, the Pup drifts behind Sirius when the drive is not running and is therefore nearly true E of Sirius.

Chris

Hi Chris

I'm a bit confused ( I'm a new observer). In your image it appears on the right of sirius. If the drive is turned off, does image move to left. Must do, for the pup to follow? 

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22 minutes ago, markclaire50 said:

Hi Chris

I'm a bit confused ( I'm a new observer). In your image it appears on the right of sirius. If the drive is turned off, does image move to left. Must do, for the pup to follow? 

Yes, the star moves to the left (W), followed by the Pup. When I set up the camera on the Mak, I play around with the rotation until it is aligned correctly (ie like a compass rose).

(If you have the book "Turn Left at Orion", there are nice graphics on p13 showing the orientation through the eyepiece for each type of scope. Ones with a star diagonal, like the Mak, show true compass orientation, ie E and W reversed compared with the naked eye.)

Chris

Edited by chiltonstar

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Different scopes show different orientation in what is seen at the eyepiece.  Standard Newtonians have an inverted south is up view with east to the right.   Refractors, SCTs, Maksutovs - when using a standard 90 degree diagonal they flip the view east / west so north is up, east is to the right.  It can get somewhat confusing.......

However the confusion can be resolved by keeping in mind which way is up in the scope you’re using, then if your scope has a drive, turn it off.  Whatever scope you’re using stars will exit the field of view on the west side and new stars will enter on the east side.  Sorted 😀

Ed

Edited by NGC 1502
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26 minutes ago, chiltonstar said:

Yes, the star moves to the left (W), followed by the Pup. When I set up the camera on the Mak, I play around with the rotation until it is aligned correctly (ie like a compass rose).

(If you have the book "Turn Left at Orion", there are nice graphics on p13 showing the orientation through the eyepiece for each type of scope. Ones with a star diagonal, like the Mak, show true compass orientation, ie E and W reversed compared with the naked eye.)

Chris

Thanks Chris. So, when you say drifts to left (W), in reality does this mean it is moving to the right towards the western horizon ( when not looking through scope) but we see if move to the left (W compass point) in the fov of scope because image is reversed right to left? 

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4 minutes ago, NGC 1502 said:

 

Different scopes show diferent orientation in what is seen at the eyepiece.  Standard Newtonians have an inverted south is up view with east to the right.   Refractors, SCTs, Maksutovs - when using a standard 90 degree diagonal they flip the view east / west so north is up, east is to the right.  It can get somewhat confusing.......

However the confusion can be resolved by keeping in mind which way is up in the scope you’re using, then if your scope has a drive, turn it off.  Whatever scope you’re using stars will exit the field of view on the west side and new stars will enter on the east side.  Sorted 😀

Ed

Thanks Ed. I think I was coming to that conclusion from chris' reply. So, then, on the sky safari pro, when it shows pup on left, that is true orientation and same for everything else.We just have to reverse it in our heads? 

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5 minutes ago, markclaire50 said:

Thanks Chris. So, when you say drifts to left (W), in reality does this mean it is moving to the right towards the western horizon ( when not looking through scope) but we see if move to the left (W compass point) in the fov of scope because image is reversed right to left? 

Yes, that's right Mark. Maks, SCTs and refractors do this, whereas DOBs invert.

Chris

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2 minutes ago, markclaire50 said:

Thanks Ed. I think I was coming to that conclusion from chris' reply. So, then, on the sky safari pro, when it shows pup on left, that is true orientation and same for everything else.We just have to reverse it in our heads? 

You can set up the SkySafari to be reversed like your scope view - this may help but I personally find it confusing.

Chris

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11 hours ago, mikeDnight said:

To be honest Mark, I've really struggled with the Pup. It's always in turbulent air from my site, though I have a feeling I've seen it situated on the first diffraction ring but can't be certain. 

I've seen the E&F stars numerous times in my FS128,  SW 120ED  Equinox and in my FC100DC. As has already been mentioned, steady seeing, a thermally stable scope and sharp optics are needed. The E & F stars are not dim, but because they are close to the brighter trapezium stars, they can be a challenge. I've attached two sketches. The 100mm Tak sketch shows the stars relative positions and distance from the trapezium. The 14" SCT sketch at high power doesn't reveal them. 

2116376458_2019-02-0521_29_19.png.9c7a6c4e794a7053034d0e60dd4da1de.png E & F stars as seen in a 100mm apo.

981280445_2019-02-0521_27_40.png.9c4ba94e5d2ab55730dadc301c8227a9.png Trapezium as seen through a 14" Celestron SCT.

Amazing sketches Mike, just superb !

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Hi Mark,

Welcome to SGL.

Just last week, using my 12" OOVX dob, I got E&F quite solidly (180X), but on neither occasion could I see Sirius B. The seeing was good enough for E&F to be quite distinct, and may have been good enough for Sirius B, but being that much lower in the atmosphere, Sirius A was scintillating too much to pick out the Pup star.

The same evenings I got E&F with my Tak FC100 also, but not the Pup.

Three years ago was the last time I saw the Pup and that was through my 5" F15 refractor, on a night with stable atmosphere. At least one other member of this forum had success that evening as we were conferring, via SGL, to be sure that we could both see it. :smiley:

Edited by Saganite
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3 hours ago, chiltonstar said:

Yes, that's right Mark. Maks, SCTs and refractors do this, whereas DOBs invert.

Chris

Thanks Chris. That's almost a good reason for sticking with maks, fracs and scts! 

Edited by markclaire50

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5 hours ago, markclaire50 said:

Hi John. That's where I was looking. Chris' photo shows it to the west though. I've just checked on Google and indeed for a mak, the image is reversed, so it would be in front of star. For a newt, it would follow. So, I was focusing my eyes in the wrong place. Not that anything leaped out from either side! 

My point was that the Pup star trails behind the primary star as it drifts across the field in whatever scope you view though. It's certainly not going to leap out - a tiny barely detectable glimmer occasionally.

 

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2 hours ago, John said:

My point was that the Pup star trails behind the primary star as it drifts across the field in whatever scope you view though. It's certainly not going to leap out - a tiny barely detectable glimmer occasionally.

 

Thanks John. Being a newbie, I was just trying to understand what's going on. 😊

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16 minutes ago, markclaire50 said:

Thanks John. Being a newbie, I was just trying to understand what's going on. 😊

Being an oldie, so am I most of the time :grin:

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I've seen E and F clearly with my 14" dob. I've only recorded seeing A-D with smaller scopes from 80mm to 200mm but sessions with smaller scopes are often short with a scope not fully cooled and light pollution to contend with.

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Trapezium E and F easy to see this evening around 6.30pm with a 16" SCT which often struggles unless the conditions are good. Interestingly I couldn't see them in a 20" Dob or a 6" refractor.     :icon_scratch:

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I had a great view of the nebula as well as the E & F stars in the Trapezium this evening, despite the nearness of the Moon, using a 16mm Nagler & 2X Ultima barlow in my 100mm Tak. 😆

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On 06/02/2019 at 09:42, Saganite said:

Hi Mark,

Welcome to SGL.

Just last week, using my 12" OOVX dob, I got E&F quite solidly (180X), but on neither occasion could I see Sirius B. The seeing was good enough for E&F to be quite distinct, and may have been good enough for Sirius B, but being that much lower in the atmosphere, Sirius A was scintillating too much to pick out the Pup star.

The same evenings I got E&F with my Tak FC100 also, but not the Pup.

Three years ago was the last time I saw the Pup and that was through my 5" F15 refractor, on a night with stable atmosphere. At least one other member of this forum had success that evening as we were conferring, via SGL, to be sure that we could both see it. :smiley:

I think I may be the colleague Steve was referring to 3 years ago..It's scary to think that is how long it is since I first glimpsed the Pup in my Vixen ED103s refractor. Thay was back in LP plagued Leicestershire..since we moved to rural Lincolnshire 2 years ago, I haven't seen it since, even with my FS128, although the E & F stars are easy when the sky is steady. Buy we do have a micro climate here, being surrounded by low hills, and some nights although darker than the Midlands, the seeing just isn't there..

Sadly, tonight the sky is like jelly here..I couldn't even split Rigel, and the moon is overpoweringly bright and shimmering non stop. Very disappointed tonight😢..

I hope others in here have much better seeing this evening..

Dave

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On 15/02/2019 at 20:25, F15Rules said:

I think I may be the colleague Steve was referring to 3 years ago..It's scary to think that is how long it is since I first glimpsed the Pup in my Vixen ED103s refractor. Thay was back in LP plagued Leicestershire..since we moved to rural Lincolnshire 2 years ago, I haven't seen it since, even with my FS128, although the E & F stars are easy when the sky is steady. Buy we do have a micro climate here, being surrounded by low hills, and some nights although darker than the Midlands, the seeing just isn't there..

Sadly, tonight the sky is like jelly here..I couldn't even split Rigel, and the moon is overpoweringly bright and shimmering non stop. Very disappointed tonight😢..

I hope others in here have much better seeing this evening..

Dave

Hi Dave,

You were indeed, and we both were seeing the 'Pup' in the same position, so there was no doubt about it. It is amazing that it was that long ago, but it just underlines what we in the UK have to put up with, as regards sky for good observing. Having said that I have recorded 12 hours of observing in the last two weeks, so I should not complain. Last night I managed 7 Plato craterlets, and 2/3rds of that damn Rille in the Alpine Valley, after staring at it for two hours, and then only for brief moments , as the seeing calmed. The E&F stars have been easy on three occasions, as they probably should be with a 12" 1/8 wave Dob, but The scope with which I last saw the Pup has, for a number of reasons, been unavailable for 4 months now, and I miss its ability to punch through mediocre seeing.

Edited by Saganite
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I've 9nly ever seen the E and F stars once in my 6" F5 newt a few years back one December night when it was frosty and clear as a bell.

I tried in the 8" but never managed it tried with my Tal 100rs could not get it.

I am hoping for a really frosty clear night when I can try my 5" Meade Refractor.

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Although I have never had any success myself, I have read that one thing that can help in finding the pup is to use a Y-mask lined up so that the diffraction spikes run N-S. This apparently reduces the glare of the star in the E-W direction. Although the pup is also diffracted, the effect is much less and so relatively it becomes easier to see. That's the theory, but, as I said, I've never had any success myself.

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3 hours ago, Demonperformer said:

Although I have never had any success myself, I have read that one thing that can help in finding the pup is to use a Y-mask lined up so that the diffraction spikes run N-S. This apparently reduces the glare of the star in the E-W direction. Although the pup is also diffracted, the effect is much less and so relatively it becomes easier to see. That's the theory, but, as I said, I've never had any success myself.

You'd think someone would make an eyepiece with an occulting bar, or a thick wire (enough to block a star). I know, that's tantamount to cheating!

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