(IAAC) Obj: NGC6934 - Inst: 4.5" Homemade Dobson reflector, f/8
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Subject: (IAAC) Obj: NGC6934 - Inst: 4.5" Homemade Dobson reflector, f/8
From: Ante Perkovic <email@example.com>
Date: Tue, 10 Aug 2004 16:39:22 +0200
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Observer: Ante Perkovic
Your skills: Intermediate (some years)
Date/time of observation: July 22nd 2004., 0:30h
Location of site: Kasjuni beach, Split, Croatia (Lat. 43.5 N, Elev. 0m)
Site classification: Suburban
Sky darkness: 5.0 <Limiting magnitude>
Seeing: 5 <1-10 Seeing Scale (10 best)>
Moon presence: None - moon not in sky
Instrument: 4.5" Homemade Dobson reflector, f/8 ("babydob")
Magnification: 25x, 48x, 79x, 140x
Category: Globular cluster
Data: mag 8.9 size 2.0'
25x: The cluster is at the end of the line of 3 stars
with mags 9 to 10.5. The closest star is 2' to the
W while remaining 2 stars are 8' and 10', respectively,
to the W of the cluster. The cluster and 3 stars looks
like this 4 characters: * . . .
The cluster appeared to almost touch the neighboring
star and I estimated it's diameter to be 3'. This is
the first time that some globular looks bigger to me
than it really is. Usually, my estimated diameters are
between 1/3 and 1/5 of the real diameter!
48x: The cluster shrinks a little, but it's still as big as 2'30"!
79x: With direct vision, I see a uniform moderately bright
nebula. Averted vision shows central brightening. I
called my friend Igor to help me estimate the diameter
of the cluster by comparing its diameter with the
distance (1'52") between the cluster center and the
neighbouring star. His diameter estimate was 2'40,
while mine was 2'. I finally confined this cluster to
its real borders :).
140x: The cluster looks even smaller!