How To Observe Sirius B

[Refractordude]

https://florin.myip.org/blog/how-see-sirius-b

https://www.solarsystemquick.com/univer ... s-star.htm

https://www.universetoday.com/44985/sirius-b/

[yobbo89]

Wow, I never knew this! Thanks a heap for the info

[yobbo89]

I actually have used sirus many times as a defocused star test and always thaught there was some sort of internal reflection going on, I guess it turns out there's something going on in the foreground!

[Bigzmey]

Right! It is the Pup season again. Burning retina on Sirius and popping eyes on the Horsehead are astronomers rite of passage.
Both done in winter.

[bladekeeper]

My two log entries:

8. Sirius - α Canis Majoris - NEW
(Double Star in Canis Major)
Observed: Jan 24, 2018 at 21:09:54
Comment: I first put an eye to the KK in the 80. Sirius was bright and twinkling a bit with the atmospheric turbulence. Seeing wasn’t terrible, but it could have been better. I studied the star for a bit but no Pup did I see. Moving over to the 127, I watched the star for a minute and kept thinking I was picking up a small little pip of light on the lower right side of the star. Well, I wasn’t sure of Sirius B’s position angle, so I pulled it up on SS5. Bah! It’s on the other side of Sirius A! I was merely catching some kind of artifact. Then I realized I still had SS5 oriented to match my RACI view. I did a horizontal flip to match my frac eyepiece view, and this placed the Pup in the exact spot I was seeing my little dot of light. Back at the eyepiece, I watched the blazing star and again could see my little dot. It wasn’t steady but would appear for a few seconds then disappear as turbulence waxed and waned, only to pop back into view again. It always stayed in the same spot. I swapped out for the BCO 10mm. At 83×, the chromatic aberration was rather intense, and I did not pick up the secondary. Back to the 82° 18mm, my little dot again appeared in the same spot tucked up next to Sirius A. I was now satisfied I was picking up Sirius B. Pretty darn cool.
Equipment: Premium 80, KK Ortho 18mm, AR127, ES 82° 18mm, BCO 10mm

6. Sirius - α Canis Majoris
(Double Star in Canis Major)
Observed: Mar 16, 2018 at 21:47:50
Comment: Just goofing around here with an aperture mask on the dob. In my case, the dust cover with the little hole uncapped. I defocused the star at 84× and achieved an excellent Airy disk with wonderfully concentric circles. Collimation is pretty good, I suppose. Seeing is a little rough, but very occasionally the little pip of Sirius B pops into existence.
Equipment: AD12, KK Ortho 18mm

[dagadget]

Lets see I have a C 11 an AT 152EDT a Sky watcher Mak Cas 180 as my scopes. Probably will catch it best in the Big Frac. Never really tried for the pup as a main course but have seen it before when someone else had found it.

[Bigzmey]

Lets see I have a C 11 an AT 152EDT a Sky watcher Mak Cas 180 as my scopes. Probably will catch it best in the Big Frac. Never really tried for the pup as a main course but have seen it before when someone else had found it.

All 3 scopes would be more than capable, and it will come down to how good the seeing is.

[John Baars]

I first saw the Pup in January 2011 with a 14" SCT. Since, I have observed it several times. With several telescopes. Even as small as a 4 inch ED refractor. The pup is some 11 arc-seconds separated from Sirius now and the system is still opening until 2025 to 11.5 arc-seconds or so. In 2020 it will be located East of the main star, a tad to the North.

Over the years I found out there are two "schools" about how to discover the Pup.
Both agree on very clean optics and excellent seeing, and if possible, transparency. Both agree on slewing to the west: The Pup follows the main star and becomes a tiny bit easier to spot.
One tells us to take the magnification high up, in order to separate the two stars more easily. One can even put Sirius outside the field of view. The other tells us to keep it moderate, in order to keep the faintest seeing speckles at a very low level. In fact both ways seem to work for several observers. One should try both ways. Once seen, next time it becomes a bit easier.

My most succesfull observations were at 75X to 100X. The moderate magnification school. The last observation was done with a 120mm F900 doublet Evostar and 12mm Brandon / 9mm Fujiyama eyepieces. But don't count yourself rich. In just 8 years only 6 observations were a very positive "Yes". Some 50 of them failed. But that was from a LP city at 52 degrees Latitude. I have read reports from observers in The Sahara desert (Africa) at 30 degrees which were far more enthusiastic.

A sketch of where to find the Pup in a 0,5 degree (approximately 100X) field with the three accompanying stars. If you fail to see all three of them, you'd better stop

[Bigzmey]

Nice summary John! I got the Pup twice with 8" SCT and 127mm APO frac. Both times pushing to high powers and blocking Sirius A with EP's field stop. I guess I belong to the first school. I also had 10+ failed attempts before and after the success.

[helicon]

Thanks for the tips. I am going to go for it in the 6" frac.

[depratnt]

im gonna give this a shot with my dob! not sure how mch our terrible seeing here in colorado will effect my success but we shall see

[John Baars]

(...) I am going to go for it in the 6" frac.

A 6 inch Achromat will do the job.
I had to adjust my mount this evening, for It was moved by a builder to make room in order to install new window frames. Seeing was rather good, as well as transparancy. After polar aligning I turned to Sirius, the first time this season. And there it was, the Pup. A bit surprised! Not really difficult if seeing and transparancy are near perfect. Pity those circumstances ( both being very good) are very rare.

[Refractordude]

Just got back in from trying to see Sirius B. I could not do it using a 120mm f8 achromatic at 142, 166, and 285 magnifications. The seeing conditions are very good this evening/morning with no wind. I live under bortle 9 skies, but the nebulosity of Orion was the brightest I have ever seen it. There was a moment when I saw a pimple at the lower lift side while out of focus at 285 magnification. However, I am not certain that was Sirius B. I think I have to spend more time going in and out of focus at high mag. Sirius B may be a ghost like object that comes and goes. Has anyone seen Sirius B with 120mm or less aperture?

[bladekeeper]

Just got back in from trying to see Sirius B. I could not do it using a 120mm f8 achromatic at 142, 166, and 285 magnifications. The seeing conditions are very good this evening/morning with no wind. I live under bortle 9 skies, but the nebulosity of Orion was the brightest I have ever seen it. There was a moment when I saw a pimple at the lower lift side while out of focus at 285 magnification. However, I am not certain that was Sirius B. I think I have to spend more time going in and out of focus at high mag. Sirius B may be a ghost like object that comes and goes. Has anyone seen Sirius B with 120mm or less aperture?

In my notes above, the first observation was with a 5" refractor. That one is a little faster than yours, but in my mind, your f/8 is certainly more than capable.

Yeah, Sirius B will pop in and out as you hit smooth pockets of atmosphere. It's a bit tough. It's not Pluto tough, but it's reasonably challenging. My observation with the 5" above was done at 46×. To me, the observation on that night had more to do with exit pupil than power. I was between a 2.5mm and 3mm exit pupil there.

But, every eye is different, not to mention the LP levels, seeing/transparency on a given night, scope, eyepiece, experience, tiredness, stress, mindset, all factors in the observing.

Keep trying. I had given it many tries before that first observation and I failed. Now if you want to talk Horsehead, I can show you a whole notched belt of failures...

[notFritzArgelander]

Just got back in from trying to see Sirius B. I could not do it using a 120mm f8 achromatic at 142, 166, and 285 magnifications. The seeing conditions are very good this evening/morning with no wind. I live under bortle 9 skies, but the nebulosity of Orion was the brightest I have ever seen it. There was a moment when I saw a pimple at the lower lift side while out of focus at 285 magnification. However, I am not certain that was Sirius B. I think I have to spend more time going in and out of focus at high mag. Sirius B may be a ghost like object that comes and goes. Has anyone seen Sirius B with 120mm or less aperture?

In my notes above, the first observation was with a 5" refractor. That one is a little faster than yours, but in my mind, your f/8 is certainly more than capable.

Yeah, Sirius B will pop in and out as you hit smooth pockets of atmosphere. It's a bit tough. It's not Pluto tough, but it's reasonably challenging. My observation with the 5" above was done at 46×. To me, the observation on that night had more to do with exit pupil than power. I was between a 2.5mm and 3mm exit pupil there.

But, every eye is different, not to mention the LP levels, seeing/transparency on a given night, scope, eyepiece, experience, tiredness, stress, mindset, all factors in the observing.

Keep trying. I had given it many tries before that first observation and I failed. Now if you want to talk Horsehead, I can show you a whole notched belt of failures...

Good observations! "Endeavor to persevere!" on the HH. If O'Meara can do the HH in a 4" TV Petzval and I can reach it with my SV ED 80 Access (with a 5mm exit pupil and H-beta filter) you should surely detect it in your SV 100 triplet weather permitting.

[John Baars]

(...) Has anyone seen Sirius B with 120mm or less aperture?

Yes, I saw it with
- 4 inch in 2012, 2014 and 2017
- 120mm in January 2019
and in 2011, 2013, December 2019 with larger apertures.

As stated above by Bladekeeper, there are more important factors that will influence the visibility.
Chances are you will not be able to observe it for months. Just keep on going!!!

At moderate magnification you are looking for a lightsparkle (needlepoint) that repeatedly stands still for more than 10-15 seconds, and that comes back over and over again on the same (right) spot. Even then you will have to change to another eyepiece and rotate it, to be sure you are not looking at some optical artefact of any kind.
Here under the turbulent Dutch skies I never managed to observe it with high magnifications. There is just too much turbulence. At very high magnifications the brightness of the airy-disc of a magnitude 8.44 star is simply lost in the seeing speckles, sparkles, strings and outliers of the main star. At least here in Holland, with the moderate apertures I am using.

[Refractordude]

(...) Has anyone seen Sirius B with 120mm or less aperture?

Yes, I saw it with
- 4 inch in 2012, 2014 and 2017
- 120mm in January 2019
and in 2011, 2013, December 2019 with larger apertures.

As stated above by Bladekeeper, there are more important factors that will influence the visibility.
Chances are you will not be able to observe it for months. Just keep on going!!!

At moderate magnification you are looking for a lightsparkle (needlepoint) that repeatedly stands still for more than 10-15 seconds, and that comes back over and over again on the same (right) spot. Even then you will have to change to another eyepiece and rotate it, to be sure you are not looking at some optical artefact of any kind.
Here under the turbulent Dutch skies I never managed to observe it with high magnifications. There is just too much turbulence. At very high magnifications the brightness of the airy-disc of a magnitude 8.44 star is simply lost in the seeing speckles, sparkles, strings and outliers of the main star. At least here in Holland, with the moderate apertures I am using.

Will keep trying at every outing. I am certain I will see it before spring.

[Kanadalainen]

To the OP, John, Bryan, Andrey et al.,

Thanks for the great stack of info.

I have not yet seen the pup in 3 years of trying! I'm using an 80mm long focus refractor but I would like to put my dob on this (14.5" main optic).

I am waiting for a good night (a still atmosphere) at the cabin with nice dark skies.

Kind regards,
Ian

[John Baars]

The second day of Christmas a Belgium observer wrote the following on the Dutch Astroforum.
Translated:

At a magnification of x50 I immediately got hold of Sirius B (in my 30 cm dob). Not visible all the time, but occasionally he jumped neatly into the picture (luckily just under a spike). The Pup was less visible at x92 and x171. x240 and x343 on the other hand gave the best result. Both 'schools' therefore certainly have a share of the truth.

No further comment needed

[John Baars]

The Belgium observer posted his sketch through his Newton today. I think the second sketch looks very realistic.
See the link here:
https://www.astroforum.nl/forum/visueel ... s-sirius-b