It's that season again - the hunt for "the Pup Star" - Sirius B

[John]

Well, Winter is here (in the northern hemisphere) and Orion is rising earlier and earlier so Canis Major and in particular Alpha Canis Majoris or Sirius will be starting to show at a more civilised time.

Here is a chance to give a real test to your scope, eyepieces and your observing eye, spotting Sirius B. Sirius B or "the Pup" as it is affectionately known is a white dwarf star which is reckoned to be around the diameter of the Earth and yet having a mass similar to our Sun. Sirius B orbits Sirius A at a distance that is roughly similar to the distance that Uranus orbits our Sun at.

I posted this 3 years ago and I hope it is still relevent and useful. Good luck ! 🙂

 

 

 

Edited December 19, 2023 by John

[RobertI]

Thanks John, I’ll have another more serious go this year. I think I may have to go to my local park to get away from the houses and get a better southern view, but even then I’m not sure I have the right scopes for the job, the 102ED being possibly too small and the C8 just not having good enough optics (“hairy stars”). Perhaps the 150PL? But I’ll re-acquaint with your excellent post to help me decide.  

Edited December 19, 2023 by RobertI

[GordonD]

Thanks John. Yes another season with fingers crossed. Not managed this yet but not for want of trying! As for Rob I suspect my 120 is too small and 'hairy' definitely describes the star in the Dob. Still a good reason to ignore the cold and get out there. 🤞

[Highburymark]

Still haven’t seen it with any of my refractors up to 120mm - I suspect because it’s so low and I observe from the city, so I’m not expecting anything this winter either. But I’ll continue trying. Would definitely rank among the more memorable ‘firsts’ in astronomy if I do manage it one day.

[Bugdozer]

I don't think I stand a chance. I made the mistake of trying to look at Sirius after my eyes were dark adapted last time I was out, it was like being stabbed by a flashing laser. No way I could see the companion. 

[John]

Here is a sketch I made a couple of years ago using my ED120 refractor. The Pup star has been to the E and slightly N of Sirius the the past few years and trails behind it as Sirius drifts across an undriven field of view.

 

[PeterStudz]

I’ve only had a few half-hearted attempts but this has given me a bit of enthusiasm to try again. 

By the way… beautiful sketches which look so natural. I wish that I could do something like that. Maybe time to practice and try again. 

[Mr Spock]

I grabbed it in the 4" a short while ago. It wasn't easy though.

[Astronomist]

I'm going to give the pup a go this year, but I suspect the seeing and my dob's TDE might hold me back. I will give it as many attempts as possible though and hope for good seeing 🤞

[John]

1 hour ago, Astronomist said:

I'm going to give the pup a go this year, but I suspect the seeing and my dob's TDE might hold me back. I will give it as many attempts as possible though and hope for good seeing 🤞

As long as you can get a sharp image in the central region of the field of view, you should be in with a chance. In terms of the separation it is not a difficult split - around 11 arc seconds currently so similar to Rigel and it's companion. It's the brightness and glare from Sirus A that creates the challenge with the much dimmer (10,000 times dimmer in fact) "Pup" star usually glimmering through the haze of light that surrounds it.

Here is another interesting, and recent, piece on this challenge:

Sirius B: Now is the best time to see Sirius’ companion (earthsky.org)

 

Edited January 5 by John

[F15Rules]

Thanks John, that's a very useful article, especially the section on the importance of preparation of both scope and the equipment such as eyepieces and other accessories.

I've been lucky enough to see the Pup just a few times, with a Vixen ED103S 4" refractor and my current 5" Tak FS128..interestingly, I've only managed to definitely see the Pup once with my Tak 5" in Bortle 4 skies here in Lincolnshire, compared to 3 or 4 times with the 4" Vixen back in the Midlands with Bortle 5 skies.

This, I think, shows that a whole series of factors need to slot into place, just as stated in the article, not just darkness or aperture: seeing, scope cooling and air temperature all have to come together at the same time - something that sadly doesn't happen that often in the UK!

But perseverence definitely pays off.

I wonder if any of our colleagues here on SGL have seen the Pup in Binoviewers?.. I certainly havent!🤔

Dave

Edited January 5 by F15Rules
Additional text info

[Mr Spock]

For me it's seeing conditions. Mine are fairly bad low down to the south so unless it's really steady there's no chance. But I have grabbed it a few times now and it's always when the seeing is rock steady further up so Sirius isn't quite dancing as much.

[Space Hopper]

Arrr, the proverbial glitter ball, and the futile hunt for its hidden companion !!

I've spent many an hour trying to spot it, with no luck so far even with 140mm aperture.

I like to think my scope and eyepieces are decent enough, but poor local seeing, Sirius' low elevation and my own failing eyesight tip the balance the wrong way.

One thing of note  : I don't think i've been using enough magnification. I've read you need around 300x but i've been using only half that as i routinely tend not to over magnify things by preference.

So i will try my newly acquired 3.5mm Vixen LWV (280x) and my personal favourite Docter 12.5mm + quad powermate (313x) and see if i have any joy......

 

 

[Mr Spock]

9 minutes ago, Space Hopper said:

So i will try my newly acquired 3.5mm Vixen LWV

Welcome to the club 

[Space Hopper]

7 minutes ago, Mr Spock said:

Welcome to the club 

Second time around for me......😀

I'll hopefully get a crack at it in the next 2 or 3 days as we should have some settled weather on the way.

[John]

The low altitude that Sirius reaches in the UK certainly does not help this challenge. I guess that from parts of the world where Sirius rides high in the sky, spotting the Pup is somewhat easier !

They probably wonder what the fuss is about 🙄

 

[Ags]

I might have some clear sky this weekend. I am not sure to try with my 90 mm refractor (too small?) or my C6 (stars too hairy?).

[wookie1965]

Only seen it once which was early last year with my 5" Meade refractor with a barlowed 6mm and putting Sirius just out on the edge of the FOV.  I wish I had not sold that now, 1 of two of the biggest mistakes of my astronomy hobby.

[Saganite]

All the prerequisites for seeing Sirius B have been mentioned, but as Dave ( F15  Rules ) said, perseverance is needed.  Last Winter I glimpsed the Pup several times during the 40 odd minutes that I observed it, as the seeing fluctuated, as it does, unless it is perfect..

[Saganite]

My previous post set me thinking, starved as I am of stargazing thanks to all this wretched rain, and I looked back through my folder of observing notes and it was 16th Jan 2023 to which I referred.  Recorded as Pickering 6 with very good transparency, it was indeed a stunning session of some 4 hours duration, during which I finally captured Orionis 52 and 32 ( a challenge started by John's  observation of them a year or so before, at which I had failed several times ), E&F in the Trapezium, and the Pup at 9.37pm and several times thereafter.  I recorded the power at 343x , so no wonder I stayed out.

Prior to that memorable occasion my notes record that I saw the Pup 3 times on 5th Jan  2022, a similar time at the eyepiece, same time of year , with seeing and transparency as good, and the E&F stars at 11pm.   That night I was using my beloved Andromeda 5" f15 refractor.  How I miss that telescope...😢

Perhaps the weather is going to be kind and a 'hat trick  ' is in the offing over the next few nights, particularly Tuesday, showing clear at the moment.

If it does, then good luck to all ...

Edited January 23 by Saganite
Typo Pickering 4 should have been 6

[Geoff Barnes]

On 06/01/2024 at 10:15, John said:

The low altitude that Sirius reaches in the UK certainly does not help this challenge. I guess that from parts of the world where Sirius rides high in the sky, spotting the Pup is somewhat easier !

They probably wonder what the fuss is about 🙄

 

You're dead right there John. 

Down here in Oz Sirius rides high in the sky and spotting the Pup is one of the first things I try to start a session just to assess how good the seeing is on any given night. 

With my 12 inch Dobsonian I manage to spot it about 80% of the time. 

Now something like the Double Double in Lyra hugs my northern horizon and proves really difficult to separate,  just a fuzzy mess most times. 

Horses for courses! 

[Saganite]

10 minutes ago, Geoff Barnes said:

You're dead right there John. 

Down here in Oz Sirius rides high in the sky and spotting the Pup is one of the first things I try to start a session just to assess how good the seeing is on any given night. 

With my 12 inch Dobsonian I manage to spot it about 80% of the time. 

Now something like the Double Double in Lyra hugs my northern horizon and proves really difficult to separate,  just a fuzzy mess most times. 

Horses for courses! 

Well I love Epsilon Lyrae more than than Sirius B, so I am not complaining.....

[Ags]

Tried tonight with my Long Perng 90... it's not the scope for the job. I'll try again with my C6 on another night. Jupiter was very soft tonight - last night's superb seeing was not repeated.

[John]

14 minutes ago, Ags said:

Tried tonight with my Long Perng 90... it's not the scope for the job. I'll try again with my C6 on another night. Jupiter was very soft tonight - last night's superb seeing was not repeated.

You do need a night of pretty good and steady seeing.

I tried it a few nights back with my ED120. I've seen it quite a few times with that scope but it was not quite possible on that occasion. There are two faint stars in particular that I find need to be visible for a sighting of Sirius B to be possible. I have circled them in red in this refractor view sketch. They are around mag 11 or so I reckon but hard to see because of the brightness of Sirius A. I could barely see one of them a few nights back so I was not surprised when the Pup star did not show itself.

 

 

 

Edited January 8 by John

[Ags]

Good info, thanks! What's the diameter of that circle?