Zeta Bootis

[Jiggy 67]

Zeta Bootis is a double star with an eccentric orbit. They orbit each other on elongated paths that cause them to converge and separate wildly. At the moment they are separated by a distance similar to that of Mars from the Sun.

 I was observing it tonight....8 inch reflector with a 6mm eyepiece and 2.25 x Barlow (x375 mag) in reasonable to good seeing showed a vague resemblance to a companion hidden in the airy disc of the companion, not sure if I imagined it, I’m willing to accept that I may have done......anyone else had a go???

[ScouseSpaceCadet]

I had a go 2 nights previously with a 4" refractor up to 250x. At 0.2" separation a futile exercise but interesting nonetheless.

Keep your fingers crossed Jiggy. I'm sure one of the doubles experts will come along and confirm you bagged them. 😀

 

[John]

I've not tried this one as yet.

The Stella Doppie database has it at .25 of an arc second so I think getting any sign of elongation would be a result with any of my scopes which go up to 12 inches in aperture. The max resolution that the 12 inch can manage is, in theory, .38 of an arc second but in practice it's almost certainly less than that.

I will have a peek at some point though.

 

 

[Sunshine]

Out looking at doubles in Bootes now, definitely going to give this one a try, wish me luck!

[Jiggy 67]

6 hours ago, John said:

I've not tried this one as yet.

The Stella Doppie database has it at .25 of an arc second so I think getting any sign of elongation would be a result with any of my scopes which go up to 12 inches in aperture. The max resolution that the 12 inch can manage is, in theory, .38 of an arc second but in practice it's almost certainly less than that.

I will have a peek at some point though.

 

 

Yep, I may well have been mistaken, the only thing I can say is that it didn’t present, at high mag, as a single star, I just had the feeling that there was more than one star there, but I don’t think I resolved a second 

[Jiggy 67]

Where’s Nick..... @cotterless45 when you need him??.... 😀

[John]

Here are some other experiences with this binary:

https://www.cloudynights.com/topic/532543-zeta-bootis-tough-rascal/

https://www.cloudynights.com/topic/704580-zeta-bootis-separation/

https://www.cloudynights.com/topic/464791-last-night-zeta-bootes/

 

[Jiggy 67]

Thanks John, I’m guessing I imagined any sign of the secondary , we’ll have to wait a few years for the separation to widen

[cloudsweeper]

I'm with John on this - 0.24 arcseconds is way beyond what any of us could separate.  You'd need a very, very large aperture, and huge magnification, not to mention unbelievably good seeing.

1.0 arcsecond is difficult.  With good equipment and conditions, 0.8 arcsecond might be possible.  Much less than that would be very hard going.  And of course it all depends on the characteristics of the binary system itself.

Doug.

[John]

When you get down to 1 arc second, I think the seeing conditions become the limiting factor. 

http://www.damianpeach.com/seeing1.htm

 

 

[cloudsweeper]

12 minutes ago, John said:

When you get down to 1 arc second, I think the seeing conditions become the limiting factor. 

http://www.damianpeach.com/seeing1.htm

 

 

Yes - and so larger aperture offsets against poor seeing.  Basically, you can't get to the mag that a given ap would allow because of seeing, so a larger ap is necessary for the higher mags needed to separate really tight doubles.  And then you hit problems with manual tracking, retaining focus and "losing" the target on swapping EPs.

These things are some of the reasons why doubles-hunting is such a challenging and rewarding occupation!

Doug.

Edited April 3, 2021 by cloudsweeper