The return of Epsilon Bootis

[Moonshane]

Last night around midnight Bootes finally got high enough to clear the trees at the back of my garden. This, and the reasonably steady air, allowed me to get another view of one of my favourite double stars.

To find the constellation Bootes, look at Ursa Major and find the Plough which is right above us currently. The curve of the handle points at a bright orange star, this is Arcturus (Alpha Bootis) which is one of the more useful guidepost stars. If Arcturus is on the right of Bootes, then Epsilon Bootis is the next (less) bright star to the left on the lower half of the roughly kite shaped constellation. E. Bootis (Izar) is magnitude 2.7 (5.1 magnitude companion) and the double can be a tricky split at a separation of 2.5 arc seconds but in good seeing it is relatively achievable with most scopes at maybe 100x or more.

I see the colours as orange for the primary and pale green for the much smaller secondary and they make a really lovely pairing.

[Astro Imp]

Thanks for the report and for the guide to finding this double. I will have a go to-night so long as the cloud holds off.

[Moonshane]

it's very nice. watch for a bit like a planet and the split will emerge.

[Hypernova]

A nice report Shane

I am not one for double stars, I never can get a clean split on them generally. The collimation is usually spot on according to my Cheshire sight tube but the seeing is never really good enough to allow a nice tight point of light. It always seems to be large and uneven, this happens even though the 'cope has been cooling to ambient for a good hour or more.

[Moonshane]

cheers Tom

I agree that with reflectors the points are not as tight as with refractors but with the larger aperture they are often more readily split I think. the view was much nicer in my 6" f11 than my 12" f5.3 but on some fainter ones like Trapezium it's often better in the 12.

[Astro Imp]

Hi,

As promised I had a look at this last night. Had difficulty getting a proper split but this could have been because when I looked it was still quite low and I had to view over my neighbours' house, and I was getting a lot of atmospheric disturbance. Will have another try later when it rises clear.

[Moonshane]

keep trying Alan, you'll get it.

[Pete Presland]

it will be a while before i can see that from my obsy!