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Re: (IAAC) Obj: Alpha Ori - Inst: 10" F4.8 Equatorial Mount GP/DX
It's unlikely that you would split such as
close a star as 0.5" with that 10mm eyepiece Barry, as far as I can work out it
only gives you 120X mag, I would guess that to split a star that close you would
need near perfect seeing (Steady air, no stars "twinkling" ) your scope
collimated perfectly and cooled down as well, and about 500x +
magnification, I could be wrong but I don't think I'm far out with that
estimate.
for you to get 480X you would need either a
2.5mm or a 5mm with a barlow. In reality though (as perfect conditions etc are
so rare) Splitting of tight doubles is a job for a Refractor rather than a
reflector, that's not to say that you cannot attempt it, or enjoy Double stars
with a reflector!
Kim Gowney
----- Original Message -----
Sent: Thursday, January 03, 2002 3:06 PM
Subject: (IAAC) Obj: Alpha Ori - Inst: 10" F4.8 Equatorial Mount
GP/DX
----
Observation Poster: Barry Sharpe <barry.sharpe@btinternet.com>
Observer:
Barry Sharpe
Your skills: Beginner (< one year)
Date/time of
observation: 29th December 2001 22:54UT
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 @ 10mm
Filter(s):
None
Object(s): Alpha Ori
Category: Other.
Class:
Star
Constellation: Orion
Data: mag 0.50 size
Position: RA
: DEC :
Description:
Alpha Ori with it's deep red colour makes this
a gem, which is why i have left
it until last. I am unable to split this
double with 25mm or 10mm eyepiece. In
the FOV to the south i see 2 stars very
close together pluas a further 8 stars
on the edge of my vision. i can make
out if i concentrate really hard a star so
faint but just noticiable just
above the halo of Alpha Ori to the south this
this could be the companion?
--
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