Sirius B and e/f stars in trap - 8" newt success?

[Flame Nebula]

Hi

Previously, I've seen several posts discussing these. In this country sirius B is hard, and the e/f stars particularly f, elusive. 

My own experiences have failed with both, using SW80mm ed and 127mak.

My future weaponry is going to be the 200pds (95%probable now) on an AZEQ6. Secondary weaponry, a used SW120ED (50%probable).

I would like your opinions/thoughts/musings, on the chances of either of these scopes bringing home these astronomical delicacies? 🤔

If I recall I seem to remember John producing a nice sketch of the Pup from the 120ed. 

Location: outskirts Nottingham, bortle 6 sky ( in theory) in case this info helps. 

Thanks 

Mark 

 

Edited April 10 by Flame Nebula

[Astronomist]

You should be able to spot the pup in either of those scopes, the major obstacle there is seeing. I finally spotted the pup for the first time this year in my 10", after about 20 unsucessful attemps. In theory it should be quite easy at that aperture, but the seeing in my area is usually awful...

Best of luck with your future scopes!

[IB20]

I have an 8” dob and seen E & F stars - not particularly challenging if transparency is good.

Sirius B in theory should be easy but I haven’t managed it yet. Found the scope fails to acclimate and control the roiling mess of light that is Sirius. I’d fancy my 4” or 5” APOs would be better suited for this split.

[Flame Nebula]

20 minutes ago, IB20 said:

I have an 8” dob and seen E & F stars - not particularly challenging if transparency is good.

Sirius B in theory should be easy but I haven’t managed it yet. Found the scope fails to acclimate and control the roiling mess of light that is Sirius. I’d fancy my 4” or 5” APOs would be better suited for this split.

Hi, 

Yes I suspect you're right about sirius B. Maybe you need either a larger newt, like 12", as I know people on this forum have seen it with those, or a smaller apo. Partly the reason, inter alia, that I'm thinking of the Sw120ed, as I know at least one person on this forum has seen it with that. 

[Mr Spock]

I find in the 12" Sirius is too bright to see the pup despite its extra resolution. The 4" splits it when the seeing is good - which is not often.

[John]

52 minutes ago, IB20 said:

I have an 8” dob and seen E & F stars - not particularly challenging if transparency is good.

Sirius B in theory should be easy but I haven’t managed it yet. Found the scope fails to acclimate and control the roiling mess of light that is Sirius. I’d fancy my 4” or 5” APOs would be better suited for this split.

They are not quite equally difficult tasks from my experience. Spotting Sirius B is the tougher one and very much seeing dependant. Of course the further north you observe, the harder Sirius gets. 

 

[Stu]

Here comes the stuck record again…

Seeing….

Seeing….

Seeing….

Seeing….

Seeing….

with a bit of sky brightness and scope aperture/collimation/cooling thrown in. I think scope type is lower down the list.

Best views I’ve had of E & F have been through an AstroPhysics 130GTX (not mine unfortunately as it was/is a gorgeous scope) and more recently my 16” truss dob. Couldn’t be more different but both views were excellent with the two additional stars visible easily without any effort. The common factor was excellent seeing. On other occasions when seeing is less good the results are quite different ie E is normally easy enough but F can be much more difficult or impossible. It’s all related to seeing. I’ve seen them in the 128mm apo though yet to catch excellent seeing with this scope, and also the 4” but I find this much more difficult.

I think light pollution does play into this aswell and as a result, aperture/limiting magnitude, possibly even transparency. The E & F stars are mag 10.3 and 10.2 respectively and are embedded in the nebula so if your limiting magnitude is below that level then you won’t see them whatever the seeing conditions are like.

My 8” f8 is more than capable of catching these, and Sirius B but to be honest I have never knowingly seen the Pup in any scope in over 20 years observing and haven’t caught E and F under excellent conditions with the 8”.

So, again, I think your questions are good but without definitive answers. My lack of success with the Pup is as much about patience and perseverance (or lack of) as anything else. I don’t particularly enjoy looking for a tiny speck of light amongst the mess of seeing around Sirius, so I don’t put the hours in on it. I feel differently about trying to spot a faint star or galaxy for some reason.

Do you have any possibilities of getting to a club and trying out some different scopes? So much depends on your preferences which will potentially only become obvious with experience.

[Flame Nebula]

28 minutes ago, Stu said:

Here comes the stuck record again…

Seeing….

Seeing….

Seeing….

Seeing….

Seeing….

with a bit of sky brightness and scope aperture/collimation/cooling thrown in. I think scope type is lower down the list.

Best views I’ve had of E & F have been through an AstroPhysics 130GTX (not mine unfortunately as it was/is a gorgeous scope) and more recently my 16” truss dob. Couldn’t be more different but both views were excellent with the two additional stars visible easily without any effort. The common factor was excellent seeing. On other occasions when seeing is less good the results are quite different ie E is normally easy enough but F can be much more difficult or impossible. It’s all related to seeing. I’ve seen them in the 128mm apo though yet to catch excellent seeing with this scope, and also the 4” but I find this much more difficult.

I think light pollution does play into this aswell and as a result, aperture/limiting magnitude, possibly even transparency. The E & F stars are mag 10.3 and 10.2 respectively and are embedded in the nebula so if your limiting magnitude is below that level then you won’t see them whatever the seeing conditions are like.

My 8” f8 is more than capable of catching these, and Sirius B but to be honest I have never knowingly seen the Pup in any scope in over 20 years observing and haven’t caught E and F under excellent conditions with the 8”.

So, again, I think your questions are good but without definitive answers. My lack of success with the Pup is as much about patience and perseverance (or lack of) as anything else. I don’t particularly enjoy looking for a tiny speck of light amongst the mess of seeing around Sirius, so I don’t put the hours in on it. I feel differently about trying to spot a faint star or galaxy for some reason.

Do you have any possibilities of getting to a club and trying out some different scopes? So much depends on your preferences which will potentially only become obvious with experience.

Hi Stu, 

Seeing is believing 😉

One point you made that did jump out at me, was the light pollution/limiting magnitude. I've noticed that with the naked eye, I can't see stars above approx 4.5. That's about 1.5-2 mags below a dark sky, I believe. And this is something I've seen in my ed80, where I can't pick out stars at its theoretical limit, and interestingly, the same approximate gap exists there, where I struggle to see stars much above mag 10.5. This may be at least part of the reason it fails on the e and F. However, even with the larger 127mm aperture, I still fail, demonstrating something else is going on. Seeing? 

[Stu]

This is a useful visibility calculator. That said, it indicates 12.2 mag for a 5” scope which doesn’t tie up with 10.3 being an issue. There is the nebulosity to take into account too but not sure how much impact this has.

https://www.cruxis.com/scope/limitingmagnitude.htm

It’s a complex issue with many factors involved.

[Mr Spock]

As for E + F , they are a struggle with the 100mm due to the light pollution here. I rarely get below mag 10 on most nights. Easy peasy in the 12" though  I've not tried the 120mm yet though I know from the past that is great for picking up the nebula itself.

[John]

@Stu is quite right about the seeing being a very important factor in these challenges.

Another one, IMHO, is recognising that you are actually seeing something. That might sound an odd way to put it but these tougher challenges don't just pop into clear view when you get the goldilocks aperture / seeing combination. They go from being just beyond the threshold of being seen to just being on the right side of it but still can be very transitory, fleeting, vague and barely sensed rather than a "clean spot". With my 12 inch dob under the right conditions, E & F were so clear you simply could not miss them. With the ED120 under middling conditions, they could be hard to spot, especially F. 

So as well as "seeing, seeing, seeing" I would add "practice, practice, practice". Your 127 mak is up to these tasks I would think - you just need to keep at it, and at it, and at it ........ 

Challenging lately with the volumes of cloud and rain that we have experienced in the UK of course 🙄

Plus, the Orion and Sirius "season" is nearly over now of course.

 

Edited April 11 by John

[michael.h.f.wilkinson]

16 hours ago, Flame Nebula said:

Hi

Previously, I've seen several posts discussing these. In this country sirius B is hard, and the e/f stars particularly f, elusive. 

My own experiences have failed with both, using SW80mm ed and 127mak.

My future weaponry is going to be the 200pds (95%probable now) on an AZEQ6. Secondary weaponry, a used SW120ED (50%probable).

I would like your opinions/thoughts/musings, on the chances of either of these scopes bringing home these astronomical delicacies? 🤔

If I recall I seem to remember John producing a nice sketch of the Pup from the 120ed. 

Location: outskirts Nottingham, bortle 6 sky ( in theory) in case this info helps. 

Thanks 

Mark 

 

I have seen both the Pup and E and F in a Celestron C8, so an 8" Newtonian should be fine, but good sky conditions are a must

[Flame Nebula]

58 minutes ago, Mr Spock said:

As for E + F , they are a struggle with the 100mm due to the light pollution here. I rarely get below mag 10 on most nights. Easy peasy in the 12" though  I've not tried the 120mm yet though I know from the past that is great for picking up the nebula itself.

Hi, you have bortle 6 like me, I believe. I'm hoping with the extra grunt of an 8", I'll be able to add another couple of magnitudes. 

[Flame Nebula]

1 hour ago, John said:

@Stu is quite right about the seeing being a very important factor in these challenges.

Another one, IMHO, is recognising that you are actually seeing something. That might sound an odd way to put it but these tougher challenges don't just pop into clear view when you get the goldilocks aperture / seeing combination. They go from being just beyond the threshold of being seen to just being on the right side of it but still can be very transitory, fleeting, vague and barely sensed rather than a "clean spot". With my 12 inch dob under the right conditions, E & F were so clear you simply could not miss them. With the ED120 under middling conditions, they could be hard to spot, especially F. 

So as well as "seeing, seeing, seeing" I would add "practice, practice, practice". Your 127 mak is up to these tasks I would think - you just need to keep at it, and at it, and at it ........ 

Challenging lately with the volumes of cloud and rain that we have experienced in the UK of course 🙄

Plus, the Orion and Sirius "season" is nearly over now of course.

 

Indeed, I've noticed the seeing has been particularly bad when I nipped out to the bins, the rain was annoying too. 😂

[IB20]

I’ve bagged E with the Tak 76Q. Transparency was extremely good from memory though, bortle 5-6 skies.

[davidc135]

That's good going spotting E with with the Tak 76.

I've seen E easily with my 8.5'' f7.5 Dob under B 3/4 skies and fine seeing. F not easy, came and went. The few attempts at the pup have been unsuccessful.

David

[Flame Nebula]

20 minutes ago, davidc135 said:

That's good going spotting E with with the Tak 76.

I've seen E easily with my 8.5'' f7.5 Dob under B 3/4 skies and fine seeing. F not easy, came and went. The few attempts at the pup have been unsuccessful.

David

I wonder if the light scatter reduction of fluorite glass made a difference too? 

[Space Hopper]

32 minutes ago, Flame Nebula said:

I wonder if the light scatter reduction of fluorite glass made a difference too? 

I wouldn't think so.

I have 5.5" of Fluorite and find the 'E' star routinely difficult, but do see it from time to time.

I've not conclusively seen the 'F' star which is much harder, and never got anyway near Sirius B.

But my location has generally poor seeing and what i'd describe as 'fair on a good night.

I'm also hampered by 56 yr old eyes and am observing at 53º north, so i have to be realistic about my chances.

I do enjoy chasing these elusive targets down though. I'll get there one day.......😀

[Stu]

26 minutes ago, Space Hopper said:

I wouldn't think so.

I have 5.5" of Fluorite and find the 'E' star routinely difficult, but do see it from time to time.

I've not conclusively seen the 'F' star which is much harder, and never got anyway near Sirius B.

But my location has generally poor seeing and what i'd describe as 'fair on a good night.

I'm also hampered by 56 yr old eyes and am observing at 53º north, so i have to be realistic about my chances.

I do enjoy chasing these elusive targets down though. I'll get there one day.......😀

Just shows that there are so many variables at play; seeing, scope, eyepiece, observer etc

Even with the same scope, the eyepiece makes an enough difference to make F visible rather than inconclusive as in this report I made using my FS-128.

 

[Captain Scarlet]

Something you must ask yourself when uncertain whether you’re really seeing something is “would I see it if I didn’t know exactly where it’s supposed to be”?

And particularly with Sirius B, are you seeing “that dot” regularly in the same place, minimizing the possibility of seeing a random artifact appearing fleetingly just where you want it to?

You must be harsh with yourself about those to confidently declare a positive, in my opinion.

Edited April 12 by Captain Scarlet

[John]

24 minutes ago, Captain Scarlet said:

You must be harsh with yourself about those to confidently declare a positive, in my opinion.....

Very true. If I have any doubts at all and if I have not been able to repeat an observation at least twice, I don't put it down as having been achieved.

[mikeDnight]

On 10/04/2024 at 19:20, Flame Nebula said:

Hi

Previously, I've seen several posts discussing these. In this country sirius B is hard, and the e/f stars particularly f, elusive. 

My own experiences have failed with both, using SW80mm ed and 127mak.

My future weaponry is going to be the 200pds (95%probable now) on an AZEQ6. Secondary weaponry, a used SW120ED (50%probable).

I would like your opinions/thoughts/musings, on the chances of either of these scopes bringing home these astronomical delicacies? 🤔

If I recall I seem to remember John producing a nice sketch of the Pup from the 120ed. 

Location: outskirts Nottingham, bortle 6 sky ( in theory) in case this info helps. 

Thanks 

Mark 

 

Is the chance of probability you obtaining the telescopes, or the chance of seeing the targets?

 My late observing buddy Phil once said "Mike, you have eyes like a sewer rat"!  I think he was paying my visual acuity a complement, though in reality I'm not certain that sewer rat's have good eyesight at all. Anyhow, although I've looked for the pup many many times, I can't honestly say with hand on heart that I've ever actually seen it. There have been times where I've had a possible may be, but not a dead certainty. My problem may be due to my local seeing but whatever the reason, I'm still on the fence as someone who may have seen the pup.

 E & F stars are both observable with a 4" scope, but as with the pup, they need steady seeing rather than large aperture. I've definitely seen both the E & F stars many times when using my 4" refractor. Both the scopes you're considering could easily show both the pup and the E & F, but the seeing needs to be steady and transparent. The refractor will have the sharper cleaner star image out of the two, which may work to advantage with a relatively low object like the pup, but the 8" has the advantage of greater resolution.  Whichever you eventually choose persistence is likely going to give you the prize rather than one scope besting the other.

Edited April 12 by mikeDnight

[Flame Nebula]

28 minutes ago, mikeDnight said:

Is the chance of probability you obtaining the telescopes, or the chance of seeing the targets?

 My late observing buddy Phil once said "Mike, you have eyes like a sewer rat"!  I think he was paying my visual acuity a complement, though in reality I'm not certain that sewer rat's have good eyesight at all. Anyhow, although I've looked for the pup many many times, I can't honestly say with hand on heart that I've ever actually seen it. There have been times where I've had a possible may be, but not a dead certainty. My problem may be due to my local seeing but whatever the reason, I'm still on the fence as someone who may have seen the pup.

 E & F stars are both observable with a 4" scope, but as with the pup, they need steady seeing rather than large aperture. I've definitely seen both the E & F stars many times when using my 4" refractor. Both the scopes you're considering could easily show both the pup and the E & F, but the seeing needs to be steady and transparent. The refractor will have the sharper cleaner star image out of the two, which may work to advantage with a relatively low object like the pup, but the 8" has the advantage of greater resolution.  Whichever you eventually choose persistence is likely going to give you the prize rather than one scope besting the other.

Hi Mike, 

Probability of getting scope(s). 

Persistence and some seeing luck, seems the name of the game. 👍

 

[Flame Nebula]

1 hour ago, Space Hopper said:

I wouldn't think so.

I have 5.5" of Fluorite and find the 'E' star routinely difficult, but do see it from time to time.

I've not conclusively seen the 'F' star which is much harder, and never got anyway near Sirius B.

But my location has generally poor seeing and what i'd describe as 'fair on a good night.

I'm also hampered by 56 yr old eyes and am observing at 53º north, so i have to be realistic about my chances.

I do enjoy chasing these elusive targets down though. I'll get there one day.......😀

Well, I'm also at 53°N, with 59 years old eyes, apparently early stages of cataracts 😡, but like you, I'm going to enjoy getting these trinkets, one way or another. I love the idea of seeing a white dwarf circling a star twice as massive as our sun, only 8.5 light years away. And if we can't see it now at maximum elongation from Sirius, we never will. 👍

[IB20]

Interestingly I just revisited my notes on the E star spot with a 3”. An 83% waxing gibbous moon and a jet stream to die for. So definitely seeing, seeing, seeing!