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

[markclaire50]

Please can you tell me your experiences of seeing these objects - scope? Magnification? 

I simply cannot see them in my 127 mm mak, despite magnification up to 375x!

Tried baader zoom 8-24mm, 24 mm, 6mm and 1.5x barlow on 6mm. Nothing. On same nights I could easily pick out rigel B after 30 seconds of observing rigel. 

I'm in Midlands in uk. Sirius never gets high and shimmers like a lighthouse. I'm not so surprised about the pup, but I'm starting to think magnitude issues may be behind lack of e and f star observation. I need to see if I can see stars at mag 4 or more in my night sky, with naked eye. If I can't then my Mak may be limited to mag 10, which would explain not being able to see them

I would really like to hear the experience of people who have seen these targets 

Thank you 

Mark

[NGC 1502]

 

On a good night my 6” Dob will reveal the E&F stars in addition to the easier 4 trapezium stars at 100x or more. If the seeing is poor they won’t be seen.   In my 10” Dob E&F are much easier at similar magnifications.

Sirius B is far tougher. It took me years of trying with my 10” Dob before finally being successful on a night of excellent seeing.

Ed.

[Space Hopper]

I think in all probability, the pup is really too low to be seen from the UK,

Antares is the same. Its companion is lost in all the mush.

The E & F are a different matter.

These are do-able. You need very good optics, and a nice steady sky with decent seeing. But decent seeing here is a rarity. You need to be patient as well.

Optics must be properly cooled and well collimated.

I've seen the E on a few occasions. The F is certainly harder, but with good conditions it is there also.

 

 

[Peter Drew]

From the UK, seeing conditions are going to have the greatest affect on the ability to see these targets, there are many times when E & F Trapezium stars are invisible in our 16" SCT and other times easy in an 8". Magnification needs to be just right, too little or too much and they disappear!    ?

[des anderson]

Very frustrating to see E&F, I looked and looked and did`nt realise I had seen them,then someone on SGL put a link and bingo!! 

Try page 8 in Getting started with observing on the forum and there`s quite a few replies and lower down a link, sorry I`m not to good on a laptop. Des

[markclaire50]

9 minutes ago, NGC 1502 said:

 

On a good night my 6” Dob will reveal the E&F stars in addition to the easier 4 trapezium stars at 100x or more. If the seeing is poor they won’t be seen.   In my 10” Dob E&F are much easier at similar magnifications.

Sirius B is far tougher. It took me years of trying with my 10” Dob before finally being successful on a night of excellent seeing.

Ed.

Hi Ed. Thanks for the reply. Interesting that 6" newtonian picked it up. Someone else said their 150pds could as well. 

Looks like pup would be tough without a weapons upgrade! 

[markclaire50]

22 minutes ago, Peter Drew said:

From the UK, seeing conditions are going to have the greatest affect on the ability to see these targets, there are many times when E & F Trapezium stars are invisible in our 16" SCT and other times easy in an 8". Magnification needs to be just right, too little or too much and they disappear!    ?

Hi Peter 

Thanks for info. Amazing difference on scopes. Interesting about magnification being just right. Although I couldn't pick them out with a zoom. 

[John]

As Peter says, there seems to be a "goldilocks" magnification for seeing the E & F Trapezium stars - the trick is to find what that is with your scope under your skies !

With my ED120 refractor I find the 5mm Pentax XW eyepiece does a good job on them at 225x. I've posted a chart of the Trapezium below which might help. E is a bit easier than F.

With the Pup I feel there is a whole other layer of challenge to be honest with you and much dependant on seeing conditions in the upper as well as more local atmosphere. Our latitude in the UK does not help either.

 

[mikeDnight]

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. 

 E & F stars as seen in a 100mm apo.

 Trapezium as seen through a 14" Celestron SCT.

[Scooot]

I can usually see the E&F with my 16” at home but I don’t think I’ve ever seen them with my 10”.

[Scooot]

Ah I’ve found a sketch too.

 

[markclaire50]

5 minutes 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. 

 E & F stars as seen in a 100mm apo.

 Trapezium as seen through a 14" Celestron SCT.

Hi Mike, that is extremely interesting information! Not a result I'd have predicted at all. Is this a case of optics over aperture? (I could be opening a big can of worms on that) 

[John]

2 minutes ago, markclaire50 said:

Hi Mike, that is extremely interesting information! Not a result I'd have predicted at all. Is this a case of optics over aperture? (I could be opening a big can of worms on that) 

I occasionally manage E & F with my 102mm and 100mm ED doublet refractors. Last night, for example, I was getting E but not F with my 102mm F/6.5 Vixen ED at 205x. F did not show at all last night as far as I'm aware.

With my 12" dob though, at 200x, E & F stand out very clearly - no missing them at all with that scope.

[Klitwo]

59 minutes ago, markclaire50 said:

Please can you tell me your experiences of seeing these objects - scope? Magnification? 

I simply cannot see them in my 127 mm mak, despite magnification up to 375x!

Tried baader zoom 8-24mm, 24 mm, 6mm and 1.5x barlow on 6mm. Nothing. On same nights I could easily pick out rigel B after 30 seconds of observing rigel. 

I'm in Midlands in uk. Sirius never gets high and shimmers like a lighthouse. I'm not so surprised about the pup, but I'm starting to think magnitude issues may be behind lack of e and f star observation. I need to see if I can see stars at mag 4 or more in my night sky, with naked eye. If I can't then my Mak may be limited to mag 10, which would explain not being able to see them

I would really like to hear the experience of people who have seen these targets 

Thank you 

Mark

In the beginning "on January 31, 1862, American telescope-maker and astronomer Alvin Graham Clark first observed the faint companion, which is now called Sirius B, or affectionately "the Pup". This happened during testing of an 18.5-inch (470 mm) aperture great refractor telescope for Dearborn Observatory, which was the largest refracting telescope lens in existence at the time, and the largest telescope in the United States.  Sirius B's sighting was confirmed on March 8 with smaller telescopes".  >  https://en.wikipedia.org/wiki/Sirius

Klitwo

[Space Hopper]

The 'Pup' and Antares B are both on my bucket list.

One day.....

[John]

I've managed Antares B with my 130mm triplet refractor. Bit of a red letter night that was

[mikeDnight]

12 minutes ago, markclaire50 said:

Hi Mike, that is extremely interesting information! Not a result I'd have predicted at all. Is this a case of optics over aperture? (I could be opening a big can of worms on that) 

I suppose everyone has their own idea of a perfect telescope. For me its a good quality refractor in the 4" range, as they never fail to impress and always seem to punch well above their weight. They give great high definition, high contrast views with wide wide fields of views, while at the same time being capable of very impressive high power views. I'd hate to be responsible for that can of worms making a mess of your comfort zone. Heaven knows its not like me to try and influence anyone! 

CUTE ISNT IT!? 

[Space Hopper]

3 minutes ago, mikeDnight said:

CUTE ISNT IT!? 

It certainly is ! ?

[Klitwo]

1 hour ago, markclaire50 said:

Please can you tell me your experiences of seeing these objects - scope? Magnification? 

I simply cannot see them in my 127 mm mak, despite magnification up to 375x!

Tried baader zoom 8-24mm, 24 mm, 6mm and 1.5x barlow on 6mm. Nothing. On same nights I could easily pick out rigel B after 30 seconds of observing rigel. 

I'm in Midlands in uk. Sirius never gets high and shimmers like a lighthouse. I'm not so surprised about the pup, but I'm starting to think magnitude issues may be behind lack of e and f star observation. I need to see if I can see stars at mag 4 or more in my night sky, with naked eye. If I can't then my Mak may be limited to mag 10, which would explain not being able to see them

I would really like to hear the experience of people who have seen these targets 

Thank you 

Mark

It took a 18" Dob and 300x to see it in this S&T article.....>

https://www.skyandtelescope.com/observing/sirius-b-a-new-pup-in-my-life/

Klitwo

[John]

24 minutes ago, Klitwo said:

It took a 18" Dob and 300x to see it in this S&T article.....>

https://www.skyandtelescope.com/observing/sirius-b-a-new-pup-in-my-life/

Klitwo

I wonder where this observation took place ?

From my latitude in the UK (52 degrees N approx) Sirus is not very high in the sky - below the roof lines of many of the surrounding houses in fact so I have to observe it through relatively small gaps of clear sky. Because it's a winter target the heat plumes from the housing around me add to the scintillation that viewing at an oblique angle through more atmosphere provides to create the challange.

I imagine that observing from further south, where Sirius will be higher in the sky, must help resolve this challenging target

 

[chiltonstar]

Like the OP, I have a 127 Mak. I have managed to split Sirius A and B (the Pup) on a number of occasions from near Oxford (52 degrees), but it does take nearly perfect seeing and a very well acclimatised scope. I found it easier to image than to see, possibly because the averaging process helps reduce the seeing wobbles, for example see attached.

E and F are a different challenge with this scope - I find that they need good seeing and good transparency.

Chris

 

[NGC 1502]

2 hours ago, NGC 1502 said:

On a good night my 6” Dob will reveal the E&F stars in addition to the easier 4 trapezium stars at 100x or more. If the seeing is poor they won’t be seen. 

 

Perhaps I should clarify what my 6” Dob exactly is.   It was self built in 1994 using a premium David Hinds mirror set. The scope gives razor sharp views llmited only by atmospheric conditions.  It’s kept precisely collimated and allowed to cool to ambient before use.  The mirrors were recoated 2 years ago. It’s probably about as good as a 6” Newtonian can be.  But it takes a night of excellent seeing to reveal the E&F in the trapezium, and Orion needs to be close to the Meridian.

Ed.

[markclaire50]

2 hours ago, chiltonstar said:

Like the OP, I have a 127 Mak. I have managed to split Sirius A and B (the Pup) on a number of occasions from near Oxford (52 degrees), but it does take nearly perfect seeing and a very well acclimatised scope. I found it easier to image than to see, possibly because the averaging process helps reduce the seeing wobbles, for example see attached.

E and F are a different challenge with this scope - I find that they need good seeing and good transparency.

Chris

 

Hi Chris

Thanks for this. When I was looking for the pup, I was looking at the left hand side of the star, based on position on sky safari. Your image shows it on the right. Is this a case of the Mak causing reversed image? Should I have been concentrating on the right of the star? I don't recall seeing anything on either side, but just curious. Nice photo by the way. 

Mark

[John]

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.

 

 

 

[Guest]

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 !