A Sirius Matter -Plus-DOUBLE STAR TIPS -

[bigjoe (JOSEPH)]

Originally Posted by Tropo-Bob

Success is sweet, I have seen the Pup!

Using a C8Edge & a Tak 6mm Ortho EP, I found it, a bit further from Sirius A than I was expecting. Using Delta Gemini as a guide worked well. Delta G is like a fainter Rigel, but the secondary's magnitude is similar to the Pup so gave me a much better idea of what to look for than does Rigel.

Thanks guys for all your tips!

Well done Bob, it was once considered quite an achievement and still is in my opinion.

1: "a bit further from Sirius A than I was expecting"- is exactly what I thought also ; so we two concur here
.
2: You used a warm up PRACTICE STAR -WELL DONE BOB- IT ALL PAID OFF!

3: That Edge of yours with it's light grasp, would have kept the Pup nicely in focus, and see-able even towards the field stop-A great scope and EP, by all accounts for this- Congratulations on an achievement also.

bigjoe

[bigjoe (JOSEPH)]

Originally Posted by Bombardon

In case the time poor star splitter missed it in a previous post I grabbed this link from the last on Sirius and is a great article by the famous William Herschel on his viewing techniques, with a lot on optics and light.You will need time and a cloudy night to fully absorb this. PS: you can see I am getting viewers' cabin fever

http://rstl.royalsocietypublishing.o...ge=1&view=FitH

Thanks for this also Eugene -you keep outdoing yourself!!

PS: If I don't fall asleep -I 'll attempt a reading.

Cheers bigjoe.

[bigjoe (JOSEPH)]

Thanks once again for your contribution Steve!

I'll check it out also, and lets see if we can keep things moving in this doubles pursuit!

bigjoe.

[AG Hybrid (Adrian)]

Well spotted it again tonight. Had to wait for "sucker holes" in the clouds so I can get some clear sky for Sirius.

Here was my log of events:
*Removed cover off my 12" dob.
*Rolled it out of a rather warm garage.
*Extended the OTA to full length.
*Checked collimation and made adjustments accordingly.
*Selected a 14 min Delos. This gives about 106x magnification and an exit pupil of about 3.3 mm
*Turned on the rear fan which both cools the mirror and due to selective baffling pushes air over the primary effectively eliminating the boundary layer.
*Pointed the scope at a random star that was near where the OTA was pointing and brought it to focus.
*Waited about 2-3 min for a hole in the clouds to open up around Sirius.
*Moved Sirius to the center of the field of view in the eyepiece.
*Spotted Sirius B immediately at about 11 o'clock just above a diffraction spike located at 10 o'clock from Sirius.

This was all done in the space of about 10 minutes. Sometimes folks you just need light gathering power and resolving power. With the clouds moving fast overhead obviously seeing was pretty average too.

[Tropo-Bob (Bob)]

Originally Posted by AG Hybrid

Well spotted it again tonight. Had to wait for "sucker holes" in the clouds so I can get some clear sky for Sirius.

Here was my log of events:
*Removed cover off my 12" dob.
*Rolled it out of a rather warm garage.
*Extended the OTA to full length.
*Checked collimation and made adjustments accordingly.
*Selected a 14 min Delos. This gives about 106x magnification and an exit pupil of about 3.3 mm
....

Maybe those fans do work, I have owned both a 12.5" Dob and later a 12" Dob but never was able to split Sirius. It was closer then off course. However, like most things, once done, it becomes easier.

It might be wise to recheck the exit pupil calculations... I suspect it is closer to 2.8mm.

[AG Hybrid (Adrian)]

Originally Posted by Tropo-Bob

It might be wise to recheck the exit pupil calculations... I suspect it is closer to 2.8mm.

Too true. My mistake. Probably should not have mentioned it anyway as a main factor as switching to a XW10 brings magnification to about 152x with a 2mm exit pupil only made the split easier. Image brightness and surface brightness matters.

[The_bluester (Paul)]

Originally Posted by bigjoe

Good to hear you will do this also Paul.

With possibly the best type of SCT ever made, who some have compared to a Mewlon, because of its sharpness, contrast and longer focal length primary and coatings, I would expect you will have a great chance of cracking Sirius.

I think we would all hope to get a report from you, if you do or don't.

Cheers bigjoe.

Being a star party, if I have a go and succeed I will get someone else to have a crack as well, just to be sure.

[Allan]

Sirius is one of those targets I check every time I go out. I use it as a gauge for the sky conditions. I think it was Matt who said it, but once you've seen the pup you can't help but to see it every time, as long as the seeing co-operates.

Seeing is the most important factor, and it helps that it passes through zenith here in Oz. Aperture isn't so important, but quality is. The best view I've had of the pup was in my 5" Tak. I can see it ok in my 4" NP101, but the few times I've tried in my TV85 I couldn't see it. But I haven't been able to see the F star in the trap with the TV85 yet either.

The split is large and the pup is fairly bright at mag 8. It's all about how much scatter Sirius is throwing up in your telescope/eyepiece combination, that will determine how easy the pup is to see.

[bigjoe (JOSEPH)]

Originally Posted by The_bluester

Being a star party, if I have a go and succeed I will get someone else to have a crack as well, just to be sure.

I hope you can, so we can all compare notes on what is needed.

Goodluck.

bigjoe.

[bigjoe (JOSEPH)]

Originally Posted by Allan

Sirius is one of those targets I check every time I go out. I use it as a gauge for the sky conditions. I think it was Matt who said it, but once you've seen the pup you can't help but to see it every time, as long as the seeing co-operates.

Seeing is the most important factor, and it helps that it passes through zenith here in Oz. Aperture isn't so important, but quality is. The best view I've had of the pup was in my 5" Tak. I can see it ok in my 4" NP101, but the few times I've tried in my TV85 I couldn't see it. But I haven't been able to see the F star in the trap with the TV85 yet either.

The split is large and the pup is fairly bright at mag 8. It's all about how much scatter Sirius is throwing up in your telescope/eyepiece combination, that will determine how easy the pup is to see.

Hello Allen, great to have your input.

There's been discussion on minimum aperture; do you think that maybe you and all here, may have established that around 100mm could well be the minimum aperture required here in Sydney at least , given that Sirius is also so high in the sky, and a lot easier than some will face.

Seeing of course , but not so much it seems if you have a good 12" like Adrian , you stand a better chance, especially if you 've done it before; this definitely seems to help in the search again .

Scattering also is an issue at the EP , but having high quality optics especially APO's is also an advantage it also appears.

Cheers bigjoe.

[bigjoe (JOSEPH)]

Originally Posted by AG Hybrid

Well spotted it again tonight. Had to wait for "sucker holes" in the clouds so I can get some clear sky for Sirius.

Here was my log of events:
*Removed cover off my 12" dob.
*Rolled it out of a rather warm garage.
*Extended the OTA to full length.
*Checked collimation and made adjustments accordingly.
*Selected a 14 min Delos. This gives about 106x magnification and an exit pupil of about 3.3 mm
*Turned on the rear fan which both cools the mirror and due to selective baffling pushes air over the primary effectively eliminating the boundary layer.
*Pointed the scope at a random star that was near where the OTA was pointing and brought it to focus.
*Waited about 2-3 min for a hole in the clouds to open up around Sirius.
*Moved Sirius to the center of the field of view in the eyepiece.
*Spotted Sirius B immediately at about 11 o'clock just above a diffraction spike located at 10 o'clock from Sirius.

This was all done in the space of about 10 minutes. Sometimes folks you just need light gathering power and resolving power. With the clouds moving fast overhead obviously seeing was pretty average too.

Hello Adrian .

Yes- it now appears to be established that aperture is a big advantage in all the reports coming in; though it also appears that a nice refractor in the 100mm range will do it also, but with difficulty: VIZ Allan ; but not yet for Morton in his superb Tak.

The cooling fans also would have been a must with such a large mirror - 12" about the maximum limit of what some seasoned doubles observers say is required, so as not to be so affected by average seeing conditions, which is less of an issue with smaller much apertures.

You make it sound so easy , but it's NOT and you are a seasoned observer with vast experience, and 10 O'clock is where it should be East -following; so well done once in a remarkable time frame, and through sucker holes!!!

Cheers bigjoe.

[Allan]

Hey bigjoe. There are numerous reports of seeing it in good quality 4" refractors. I think the 3" size might be stretching the friendship, but it is up to us Southern Hemisphere observers to try. It's clear with low humidity right now, so I'll give it another go tonight.

As Adrian has posted, a 12" dob is a good scope to use and the extra aperture makes it easier. What I found side by side with my 12" dob and 5" refractor was that Sirius was a little tighter, with less flairing and scatter in the refractor, so the split was a little cleaner, and more aesthetically pleasing.

[Tropo-Bob (Bob)]

Originally Posted by Allan

Hey bigjoe. There are numerous reports of seeing it in good quality 4" refractors. I think the 3" size might be stretching the friendship, but it is up to us Southern Hemisphere observers to try.

Last night, as previously mentioned, I viewed the Pup with my C8.

I also tried to find it in my Orion 80mm Triplet, but probably with too low a magnification. However, I had been inspired with a thread on Cloudy Nights, which mentioned finding the Pup with 80mm scopes only using about 70x.

Well I tried at 80x and failed. The 80mm struggled a little even with the secondary of my test star, Delta Gemini (also at 80x). Yes, I could see it but had it look carefully, as it was faint. Whereas, the C8 immediately and clearly showed the secondary of Delta with a 30mm EP. (about 67x).

[AG Hybrid (Adrian)]

Originally Posted by Tropo-Bob

Last night, as previously mentioned, I viewed the Pup with my C8.

I also tried to find it in my Orion 80mm Triplet, but probably with too low a magnification. However, I had been inspired with a thread on Cloudy Nights, which mentioned finding the Pup with 80mm scopes only using about 70x.

Well I tried at 80x and failed. The 80mm struggled a little even with the secondary of my test star, Delta Gemini (also at 80x). Yes, I could see it but had it look carefully, as it was faint. Whereas, the C8 immediately and clearly showed the secondary of Delta with a 30mm EP. (about 67x).

Gotta watch out with those Americans. Some of those observing reports are coming from people who are observing 2-3 KM above sea level. From my home in Sydney I'm observing at about 50m.

[bigjoe (JOSEPH)]

Originally Posted by Allan

Hey bigjoe. There are numerous reports of seeing it in good quality 4" refractors. I think the 3" size might be stretching the friendship, but it is up to us Southern Hemisphere observers to try. It's clear with low humidity right now, so I'll give it another go tonight.

As Adrian has posted, a 12" dob is a good scope to use and the extra aperture makes it easier. What I found side by side with my 12" dob and 5" refractor was that Sirius was a little tighter, with less flairing and scatter in the refractor, so the split was a little cleaner, and more aesthetically pleasing.

Hello Allan.

We would all be happy to hear if you are able to do this-let alone attempt this in such a small, but superb instrument.

You'll have the advantage of a nice fat Airy Disk and fainter diffraction rings to help mitigate speckling interference with the "PUP" though, in that refractor, and no Central Obstruction to deal with.


Darkening the sky background with higher magnification will help with separation and limiting magnification naturally, and the small exit pupil may help you if the seeing is not perfect.

So let's see if you can do it!!

bigjoe.

[bigjoe (JOSEPH)]

Originally Posted by AG Hybrid

Gotta watch out with those Americans. Some of those observing reports are coming from people who are observing 2-3 KM above sea level. From my home in Sydney I'm observing at about 50m.

Exactly Adrian -Another advantage, elevation above sea level.

We're lucky though Sirius- it's almost above our heads!

bigjoe.

[bigjoe (JOSEPH)]

Originally Posted by Tropo-Bob

Last night, as previously mentioned, I viewed the Pup with my C8.

I also tried to find it in my Orion 80mm Triplet, but probably with too low a magnification. However, I had been inspired with a thread on Cloudy Nights, which mentioned finding the Pup with 80mm scopes only using about 70x.

Well I tried at 80x and failed. The 80mm struggled a little even with the secondary of my test star, Delta Gemini (also at 80x). Yes, I could see it but had it look carefully, as it was faint. Whereas, the C8 immediately and clearly showed the secondary of Delta with a 30mm EP. (about 67x).

Aperture once again it seems Bob; a clear advantage all things being equal.

I'm finding also that the trick of going back and forward between direct and averted vision helps dramatically also- until the companion is there with direct vision, and more power to help with limiting magnitude could do the trick with such a small aperture.

PS: And that 80mm Orion triplet got a great review once by Dr Clay Sherrod , so we know it's good.

bigjoe.

[AG Hybrid (Adrian)]

So... as an experiment I followed the advice that has been given so far in this thread and really gave a proper go.

I can now say I did it. It took me to the very limit of my skill and experience but I DID IT! I spotted the Pup for the first time in my $400 Explore Scientific AR102.

It took some experimentation especially deciding which view was best between using a Baader Semo-Apo filter or no filter. The CA was overwhelming on Sirius so I used the filter at the expense of a little bit of light lost.
I put my 2x barlow in front of my diagonal as to produce more magnification as it would if it were behind the diagonal and then putting the eyepiece straight into the barlow.
I then used a Baader Hyperion Zoom to gauge the best magnification and exit pupil the atmosphere would support. Atmospheric seeing was decent tonight as I observed Jupiter prior, as it rose. I was able to see four bands on Jupiter which was pretty good for the AR102 especially considering how low it was in the sky.

The advise to use Rigel in Orion as a benchmark and test object is a very wise idea. It gave me an idea what I was in for and I noted that CA was overwhelming too. Had to use the filter and glad that I did because it was the first time I saw Rigel B in the AR102 as well. While still lots of CA the little white dot was there with direct vision. Nice.

So, to Sirius. This was hard. Very hard. As I mentioned earlier the CA caused by Sirius was overwhelming at the magnification I was using. Would have been well over 200x. I would approximate that over 40% of the field was blue haze. The filter was necessary. It did a good job, the CA was less then 10% of the field now. Still rather intense around the Sirius itself, just contained. Using the zoom I gauged the best magnification to find that sweet spot between image brightness and contrast. This took some time. I also was using an alt azimuth mount which means Sirius was always on the move and moving fast. It was only a for a few seconds in the center of the field where the best field correction is and my windows of best observing were constantly being reset. But, I've never owned a tracking mount so it was second nature to me. Muscle memory even.

While watching Sirius floating from top left to bottom right going through the field it appeared as it floated through the center of the field. For about 4 seconds the little white dot appeared on the outer most diffraction ring. It looked to be about 2 o'clock. I'm certain it was a positive result as I had spent the last 30 min noting false-positives caused by eye floaters. I don't have many but they are really obvious when they do appear at that tiny exit pupil. I knew exactly how the floaters looked and how the moved and acted. That little white dot I saw stuck right by Sirius as it zoomed through the field of view. The eye floater moved around and rarely in a straight line.

Pretty pleased with that as a whole. Although next time I'm just going to roll out the 12"

[skysurfer]

Yesterday night tried again, from South Africa, seeing was rather still with ED110 + WO dielectric diagonal + Vixen LV6 (128x), but no pup.
Tonight another try.

In Holland many people claim to see the Pup despite Sirius never comes higher than 21 degrees above the horizon. But I disagree.
https://translate.google.com/transla...ius&edit-text=

Originally Posted by bigjoe

1: SEEING- Must be excellent.

2: ALTITUDE - Well above the horizon in
most instances.

3: APERTURE-100mm+Cooled and well collimated.

4: POWER- The use of it is necessary- 200x + may be needed.

5: USE A MASK- Hex , may be necessary.

6: ORIENTATION- Is your diagonal/scope displaying an upright E/W view; If not adjust accordingly.

7: PRACTISE on Rigel say - Bright, with similar separation.

8: DRIFTING- Let Sirius A drift past the field stop , and disappear, as B will surely follow.

9: WARM CLOTHING , and stool if necessary.

10: PATIENCE- and lots of it -It could take many attempts!

11. As few glass-air transitions as possible.

[Tropo-Bob (Bob)]

Originally Posted by AG Hybrid

So... as an experiment I followed the advice that has been given so far in this thread and really gave a proper go.

I can now say I did it. It took me to the very limit of my skill and experience but I DID IT! I spotted the Pup for the first time in my $400 Explore Scientific AR102.

It took some experimentation especially deciding which view was best between using a Baader Semo-Apo filter or no filter. The CA was overwhelming on Sirius so I used the filter at the expense of a little bit of light lost.
I put my 2x barlow in front of my diagonal as to produce more magnification as it would if it were behind the diagonal and then putting the eyepiece straight into the barlow.
I then used a Baader Hyperion Zoom to gauge the best magnification and exit pupil the atmosphere would support. Atmospheric seeing was decent tonight as I observed Jupiter prior, as it rose. I was able to see four bands on Jupiter which was pretty good for the AR102 especially considering how low it was in the sky.

The advise to use Rigel in Orion as a benchmark and test object is a very wise idea. It gave me an idea what I was in for and I noted that CA was overwhelming too. Had to use the filter and glad that I did because it was the first time I saw Rigel B in the AR102 as well. While still lots of CA the little white dot was there with direct vision. Nice.

So, to Sirius. This was hard. Very hard. As I mentioned earlier the CA caused by Sirius was overwhelming at the magnification I was using. Would have been well over 200x. I would approximate that over 40% of the field was blue haze. The filter was necessary. It did a good job, the CA was less then 10% of the field now. Still rather intense around the Sirius itself, just contained. Using the zoom I gauged the best magnification to find that sweet spot between image brightness and contrast. This took some time. I also was using an alt azimuth mount which means Sirius was always on the move and moving fast. It was only a for a few seconds in the center of the field where the best field correction is and my windows of best observing were constantly being reset. But, I've never owned a tracking mount so it was second nature to me. Muscle memory even.

While watching Sirius floating from top left to bottom right going through the field it appeared as it floated through the center of the field. For about 4 seconds the little white dot appeared on the outer most diffraction ring. It looked to be about 2 o'clock. I'm certain it was a positive result as I had spent the last 30 min noting false-positives caused by eye floaters. I don't have many but they are really obvious when they do appear at that tiny exit pupil. I knew exactly how the floaters looked and how the moved and acted. That little white dot I saw stuck right by Sirius as it zoomed through the field of view. The eye floater moved around and rarely in a straight line.

Pretty pleased with that as a whole. Although next time I'm just going to roll out the 12"

Adrian, that is a huge achievement if you found it in such a small scope with CA issues as well. However,I am confused about your use of the clock for directions. The Pup should trail Sirius A in an undriven scope. If I am using the clock in the same manner as yourself, my observation was that it was at about at 7 o'clock position. Given that you saw it in your 12" reflector at the 11 o'clock position, I thought our observations were in agreement when you swap the up and down positions between at refractor and a reflector. (Left and right being unchanged of course).
However, you say that you saw it at 2o'clock in the refractor.
I am not saying that you did not see it, but was there anything else going on to confuse the directions; like did you have the star diagonal twisted to the side or something?