Re: (IAAC) Obj: Zeta Ori - Inst: 10" F4.8 Equatorial Mount GP/DX


The angular separation depends both on the actually distance (miles, 
kilometers, or whatever) the 2 objects are apart as well as how far they 
are away. Example, a fist at arms length is about 5d, but 2 stars would 
have to be light years apart to have 5d between them.

The difficulty is resolving double stars depends on several factors. The 
angular separation and the magnitude difference are the main ones. Of 
course, your scope, EPs, even your own eyes play a part.

If you can get ahold of the January issue of S&T, there is a pair of 
articles bearing on this.


On Thursday, January 3, 2002, at 08:51 AM, Apache User wrote:

> ----
> Observation Poster: Barry Sharpe <barry.sharpe@btinternet.com>
> Observer: Barry Sharpe
> Your skills: Beginner (< one year)
> Date/time of observation: 29th December 2001 22:12UT
> Location of site: Welwyn Garden City (Lat 53:27:00, Elev 02:31:00)
> Site classification: Suburban
> Sky darkness: 5 <1-10 Scale (10 best)>
> Seeing: 7 <1-10 Seeing Scale (10 best)>
> Moon presence: Great - full or very near object
> Instrument: 10" F4.8 Equatorial Mount GP/DX
> Magnification: 25mm
> Filter(s): None
> Object(s): Zeta Ori
> Category: Other.
> Class: Star
> Constellation: Orion
> Data: mag 2.05h  size
> Position: RA :  DEC :
> Description:
> Zeta Ori seem,s to have a pure white colour, i can split this with my 
> 25mm the
> companion seems very close indeed but does seem to be the same colour. 
> In my FOV
> i can see a further 9 stars they seem to be the a little brighter than 
> the
> companion. The companion star is right on the edge of my vision i need 
> to
> concentrate hard to notice it. The fact that i have managed to split 
> Delta Ori
> and Zeta Ori but not Epsilon Ori is this down to distance?
> Delta Ori = 916LY, Epsilon Ori = 1342LY, Zeta Ori 817LY, Looking at the
> distances it may well be possible. Of course it may just be how close 
> they are
> but that in some part must also have something to do with distance as 
> my angles
> must get smaller over distance.
> --
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