Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Splitting Theta Aurigae

  • Please log in to reply
50 replies to this topic

#1 Stellar1

Stellar1

    Gemini

  • -----
  • topic starter
  • Posts: 3,360
  • Joined: 08 Dec 2018
  • Loc: Juuuust outside Toronto

Posted 09 March 2021 - 01:40 AM

Last summer it was Zeta Her which cause me many nights left cross eyed trying to split this difficult double till one night of great seeing I finally split them. Tonight it was back to the drawing board with Theta Aurigae which is TOUGH!!, I followed this star for what must have been 35 degrees with no luck. Using my 3.5mm XW at 230X rendered a nice pinpoint Theta Aur A, "B" caused me a headache, what i did notice was a dancing bulge ( I'll use positions on a clock) between 2 and 5 O'clock position where at times for a split second (pardon the pun) I was able to see a gap. Maybe on a better night I'll be able to see B as a pinpoint? what should my expectations be assuming seeing is good using a 4" refractor?, this one is a doozy but, I sure love a tough double. While researching this double I ran into stories of others splitting it at powers of 130-175 which I guess would depend on seeing and, aperture used, I'll be darned if I came close with those powers. Maybe the seeing just wasn't up to par as there was a lot of spinning and dancing of that second appendage next to the main star.


Edited by Stellar1, 09 March 2021 - 01:12 PM.

  • RobDob, happylimpet, Magnus Ahrling and 2 others like this

#2 Astrojensen

Astrojensen

    James Webb Space Telescope

  • *****
  • Posts: 16,783
  • Joined: 05 Oct 2008
  • Loc: Bornholm, Denmark

Posted 09 March 2021 - 02:25 AM

If the seeing is good (which it MUST be), Theta Aurigae is a piece of cake in a 4", IMO. That is, of course, assuming good optics and a reasonably experienced observer. 

 

Poor seeing can quickly render the faint companion invisible. 

 

 

Clear skies!

Thomas, Denmark


  • Jon Isaacs, gfeulner, Sasa and 4 others like this

#3 chrysalis

chrysalis

    ISS

  • *****
  • Posts: 43,663
  • Joined: 10 Aug 2013
  • Loc: North Central NC

Posted 09 March 2021 - 04:26 AM

https://www.cloudyni...-theta-aurigae/


  • flt158 and Stellar1 like this

#4 flt158

flt158

    Soyuz

  • *****
  • Posts: 3,687
  • Joined: 11 Aug 2014
  • Loc: Dublin, Republic of Ireland

Posted 09 March 2021 - 07:37 AM

I don't see all 3 components of Theta Aurigae splitting at 112X with my William Optics 158 mm F/7 apochromatic refractor. 

But at 140X I see all 3 no problem. 

I'm sorry Stellar 1 is having such difficulties with this triple star. bawling.gif  

But I do agree with others here we need good seeing conditions. 

Takahashi refractors are supposed to be of excellent quality, are they not?

 

I see on www.stelledoppie.it that the PA of the secondary is 303.5 degrees right now. 

And the separation is slowly widening. It's now almost 4.1" from the primary.  

 

Very best regards from Aubrey. 


  • Magnus Ahrling, Stellar1, rugby and 2 others like this

#5 dhkaiser

dhkaiser

    Vanguard

  • *****
  • Posts: 2,492
  • Joined: 23 Dec 2019

Posted 09 March 2021 - 08:04 AM

Wanting to take a look with my 4" refractor I went to www.stelledoppie.it which lists Theta Aurigae as a 4 star system.   However my copy of Guide 9.1 does not show the 11.1 star.  Next clear night I will give it a look to see what I can see.


Edited by dhkaiser, 09 March 2021 - 09:14 AM.

  • flt158 likes this

#6 Stellar1

Stellar1

    Gemini

  • -----
  • topic starter
  • Posts: 3,360
  • Joined: 08 Dec 2018
  • Loc: Juuuust outside Toronto

Posted 09 March 2021 - 11:47 AM

I don't see all 3 components of Theta Aurigae splitting at 112X with my William Optics 158 mm F/7 apochromatic refractor. 

But at 140X I see all 3 no problem. 

I'm sorry Stellar 1 is having such difficulties with this triple star. bawling.gif  

But I do agree with others here we need good seeing conditions. 

Takahashi refractors are supposed to be of excellent quality, are they not?

 

I see on www.stelledoppie.it that the PA of the secondary is 303.5 degrees right now. 

And the separation is slowly widening. It's now almost 4.1" from the primary.  

 

Very best regards from Aubrey. 

Pretty sure it’s the seeing, the secondary was dancing around non stop, indicative of not so great seeing. The scope put up best star test I have ever seen a few nights ago during great seeing. I’ll split it nicely on a better night. A 158 apo! that is one big frac you have there.


Edited by Stellar1, 09 March 2021 - 11:51 AM.

  • flt158 likes this

#7 gfeulner

gfeulner

    Apollo

  • *****
  • Posts: 1,037
  • Joined: 23 Nov 2007
  • Loc: Bergen county, New Jersey

Posted 09 March 2021 - 11:55 AM

Last summer it was  Theta Her which cause me many nights left cross eyed trying to split this difficult double till one night of great seeing I finally split them. Tonight it was back to the drawing board with Theta Aurigae which is TOUGH!!, I followed this star for what must have been 35 degrees with no luck. Using my 3.5mm XW at 230X rendered a nice pinpoint Theta Aur A, "B" caused me a headache, what i did notice was a dancing bulge ( I'll use positions on a clock) between 2 and 5 O'clock position where at times for a split second (pardon the pun) I was able to see a gap. Maybe on a better night I'll be able to see B as a pinpoint? what should my expectations be assuming seeing is good using a 4" refractor?, this one is a doozy but, I sure love a tough double. While researching this double I ran into stories of others splitting it at powers of 130-175 which I guess would depend on seeing and, aperture used, I'll be darned if I came close with those powers. Maybe the seeing just wasn't up to par as there was a lot of spinning and dancing of that second appendage next to the main star.

Theta Herculis? Couldn't find it as a double star.

Gerry



#8 c2m2t

c2m2t

    Apollo

  • -----
  • Posts: 1,429
  • Joined: 03 Oct 2017
  • Loc: Pembroke, Ont.

Posted 09 March 2021 - 12:25 PM

Hi Stellar!

You and I are plagued with the same thing...continuous bad seeing. I go out each night with the hope that maybe...just maybe, tonight will be the night. undecided.gif grin.gif

 

Theta Auriga, aka STT 545, has not come up yet, as I proceed through my Auriga list...otherwise I would be sharing it here. For some reason I have been neglecting our Celestial Charioteer, last visited in 2014. Will have to try and correct that this year. 

 

Cheers, Chris.


  • flt158 and Stellar1 like this

#9 Stellar1

Stellar1

    Gemini

  • -----
  • topic starter
  • Posts: 3,360
  • Joined: 08 Dec 2018
  • Loc: Juuuust outside Toronto

Posted 09 March 2021 - 01:13 PM

Theta Herculis? Couldn't find it as a double star.

Gerry

My bad, Zeta Her.


  • flt158 and Mrrodgerdelodger like this

#10 Stellar1

Stellar1

    Gemini

  • -----
  • topic starter
  • Posts: 3,360
  • Joined: 08 Dec 2018
  • Loc: Juuuust outside Toronto

Posted 09 March 2021 - 01:14 PM

Hi Stellar!

You and I are plagued with the same thing...continuous bad seeing. I go out each night with the hope that maybe...just maybe, tonight will be the night. undecided.gif grin.gif

 

Theta Auriga, aka STT 545, has not come up yet, as I proceed through my Auriga list...otherwise I would be sharing it here. For some reason I have been neglecting our Celestial Charioteer, last visited in 2014. Will have to try and correct that this year. 

 

Cheers, Chris.

I hear ya, bad seeing is the story on most nights in my neck of the woods, best of luck with your attempts! And clear skies!


  • flt158 and c2m2t like this

#11 dhkaiser

dhkaiser

    Vanguard

  • *****
  • Posts: 2,492
  • Joined: 23 Dec 2019

Posted 09 March 2021 - 08:34 PM

With the weather being forecast for clouds for the foreseeable future and a need for a very early rise time tomorrow I did a quick one hour observing tonight.  Actually started before twilight ended with Sigma Orionis and STF 761, all stars visible with Sigma Orionis C being the a little difficult do to the early start.

 

I then slewed the Lunt 102mm ED to Theta Aurigae.  With the 5mm Delite eyepiece giving 143x the B star at PA 304 and separation 4.1" was seen jumping in and out of visibility near Sigma's detraction ring.  The 10.1 mag D star at PA 349 and separation of 139" was easy.

 

The 11.1 mag C star at PA 300 separation of 56" was not seen even though I gave it several minutes to show itself.

 

I finished off the night with a favorite variable star field, OW Gem.  Being very familiar with the field I was able to see the 11.7 star but not the 12.2 star.  Not sure why I was unable to see Sigma's 11.1 C star.

 

Dan


  • flt158 likes this

#12 John Fitzgerald

John Fitzgerald

    In Focus

  • *****
  • Posts: 12,863
  • Joined: 04 Jan 2004
  • Loc: near Elkins and Pettigrew, Arkansas

Posted 09 March 2021 - 10:17 PM

I logged Theta Aur back on 3/5/2010, using a 6" f/8 achro at 200 power.  My note says the "companion is a tiny pinprick of light".


  • flt158 likes this

#13 R Botero

R Botero

    Fly Me to the Moon

  • -----
  • Posts: 5,335
  • Joined: 02 Jan 2009
  • Loc: Kent, England

Posted 10 March 2021 - 05:20 AM

I last observed Theta Aur on 28 February this year.  My most inspired notes of this pair from 17 January 2017 read:  "Beautiful white primary and faint blue sea secondary.  Significant delta.  PA315."

This with a 10" f/20 Mak at 300x.

 

Roberto


  • flt158 likes this

#14 Adam Long

Adam Long

    Messenger

  • -----
  • Posts: 482
  • Joined: 19 Sep 2019
  • Loc: Sheffield, UK

Posted 11 March 2021 - 07:51 AM

With my 10" dob this time of year, Theta Aur is one of my regular 'warm-up' pairs I visit to check the seeing and get my eye in. I must have viewed on forty or fifty different nights in the last few years. It's usually fairly easy but on a bad night can be impossible even with 10". On a good night it's a beautiful sight at 136x in my ES 8.8mm, a tiny speck closely preceding the primary. I remember it being quite a challenge the first time I saw it in my 5" dob, took a few attempts.


  • Astrojensen, R Botero, flt158 and 1 other like this

#15 SkyCruzer

SkyCruzer

    Lift Off

  • -----
  • Posts: 3
  • Joined: 02 Mar 2012
  • Loc: Santa Clarita, CA.

Posted 11 March 2021 - 08:57 PM

I was able to split it last week with my new Astrotech AT92. Using a 4mm Radian at 127X, it was  definitely there -a very tiny pinpoint just next to the main star. The seeing was almost perfect at 10pm with no moon and limiting mag of 4.5.  I had tried the previous night, and could not be sure I saw it as the seeing was poor-average. 


  • R Botero, flt158 and rugby like this

#16 fred1871

fred1871

    Vanguard

  • -----
  • Posts: 2,232
  • Joined: 22 Mar 2009
  • Loc: Australia

Posted 14 March 2021 - 11:47 PM

If the seeing is good (which it MUST be), Theta Aurigae is a piece of cake in a 4", IMO. That is, of course, assuming good optics and a reasonably experienced observer. 

 

Poor seeing can quickly render the faint companion invisible. 

 

 

Clear skies!

Thomas, Denmark

Thomas

 

have you tried Theta Aurigae with your 63mm Zeiss refractor? In good seeing conditions of course.... could be interesting (?).
 



#17 Astrojensen

Astrojensen

    James Webb Space Telescope

  • *****
  • Posts: 16,783
  • Joined: 05 Oct 2008
  • Loc: Bornholm, Denmark

Posted 15 March 2021 - 02:23 AM

Thomas

 

have you tried Theta Aurigae with your 63mm Zeiss refractor? In good seeing conditions of course.... could be interesting (?).
 

I have. It's very difficult, but doable. Older notes actually mention it as "easy"??!?!?! Now I find it very faint and very difficult to see, not so much due to the separation, but simply because it's so faint. I wonder if the companion has dimmed slightly? 

 

 

Clear skies!

Thomas, Denmark


  • Sasa and Magnus Ahrling like this

#18 R Botero

R Botero

    Fly Me to the Moon

  • -----
  • Posts: 5,335
  • Joined: 02 Jan 2009
  • Loc: Kent, England

Posted 15 March 2021 - 04:25 AM

I have. It's very difficult, but doable. Older notes actually mention it as "easy"??!?!?! Now I find it very faint and very difficult to see, not so much due to the separation, but simply because it's so faint. I wonder if the companion has dimmed slightly? 

 

 

Clear skies!

Thomas, Denmark

Or how many years since that observation? grin.gif wink.gif

 

Roberto


  • Astrojensen and flt158 like this

#19 Astrojensen

Astrojensen

    James Webb Space Telescope

  • *****
  • Posts: 16,783
  • Joined: 05 Oct 2008
  • Loc: Bornholm, Denmark

Posted 15 March 2021 - 04:58 AM

Or how many years since that observation? grin.gif wink.gif

 

Roberto

shakecane.gif gramps.gif

 

 

15-20 years... God, I feel old now.

 

 

Clear skies!

Thomas, Denmark


Edited by Astrojensen, 15 March 2021 - 04:58 AM.

  • Magnus Ahrling likes this

#20 Voyager 3

Voyager 3

    Vanguard

  • -----
  • Posts: 2,083
  • Joined: 20 Jul 2020
  • Loc: Near Bangalore, India

Posted 15 March 2021 - 06:43 AM

44 ain't old wink.gif .


  • Astrojensen, Magnus Ahrling, flt158 and 1 other like this

#21 Sasa

Sasa

    Mercury-Atlas

  • *****
  • Posts: 2,752
  • Joined: 03 Nov 2010
  • Loc: Ricany, Czech Republic

Posted 16 March 2021 - 05:31 AM

I have. It's very difficult, but doable. Older notes actually mention it as "easy"??!?!?! Now I find it very faint and very difficult to see, not so much due to the separation, but simply because it's so faint. I wonder if the companion has dimmed slightly? 

 

 

Clear skies!

Thomas, Denmark

I too split theta Aur with Telementor (still remember a night when the companion started to appear in 150mm Cassegrain after one hour of observation, then I picked from worm room 63mm Telementor and the secondary was nicely visible in about 15 minutes).

 

I was able to see the companion even in 50mm achromat (Zeiss E50/540). I could hold it with concentration even for several seconds. It appeared to be slightly bluish in contrast with yellowish tint of primary.


Edited by Sasa, 16 March 2021 - 12:10 PM.

  • Astrojensen, R Botero, Magnus Ahrling and 1 other like this

#22 Stellar1

Stellar1

    Gemini

  • -----
  • topic starter
  • Posts: 3,360
  • Joined: 08 Dec 2018
  • Loc: Juuuust outside Toronto

Posted 20 March 2021 - 05:23 PM

Last night was a night of good seeing and transparency, had no issue splitting Theta Auriga, I was surprised at how faint and small the pup is, I can see why it would be a lot more difficult when it is closer to Theta, it would easily be washed out.


  • flt158 likes this

#23 fred1871

fred1871

    Vanguard

  • -----
  • Posts: 2,232
  • Joined: 22 Mar 2009
  • Loc: Australia

Posted 20 March 2021 - 08:53 PM

Last night was a night of good seeing and transparency, had no issue splitting Theta Auriga, I was surprised at how faint and small the pup is, I can see why it would be a lot more difficult when it is closer to Theta, it would easily be washed out.

Contrast effect - the result of proximity with a big difference in brightness. 4.5 magnitudes in this case, which is about 63:1 ratio of brightness. If a lot wider, the companion at about magnitude 7.2 would not look as faint. It's a common experience with a lot of the close and very unequal doubles, that the secondary star looks much dimmer than it is. It sometimes leads to suggestions that the secondary might be a variable, when it isn't, because of the "looks less bright than the listed number" effect.  

 

Good that the conditions made seeing the pair as a pair straightforward. smile.gif  An attractive pairing when the seeing conditions are right.
 


  • Astrojensen, flt158 and Stellar1 like this

#24 Uwe Pilz

Uwe Pilz

    Skylab

  • *****
  • Moderators
  • Posts: 4,051
  • Joined: 16 May 2008
  • Loc: Leipzig, Germany

Posted 21 March 2021 - 05:59 AM

Theta Aurigae was not easy in my 4 inch refractor. But at 200x I was able to split it.

Attached Thumbnails

  • TheAur.jpg

  • payner, Astrojensen, R Botero and 4 others like this

#25 John Fitzgerald

John Fitzgerald

    In Focus

  • *****
  • Posts: 12,863
  • Joined: 04 Jan 2004
  • Loc: near Elkins and Pettigrew, Arkansas

Posted 21 March 2021 - 12:52 PM

I saw Theta Aur very well last evening in a good C14 at 225x.  It looked a lot like Rigel looks in a 6 inch.  Very easy in the C14.  Yes, probably overkill on the aperture.cool.gif.   I also saw all six stars in the Trapezium in Orion, at the same magnification.


  • Astrojensen likes this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics