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(IAAC) Message-Id: <E0xKA32-00056j-00@mail.u-net.net>
Observer:N.J.Martin
Your skill:intermediate
Date and UT of observation:Oct 7 1997 22.00UT
Location & latitude:near Ayr South West Scotland lat 55 24'56"
Site classification:bright rural
Limiting magnitude (visual):6 (zenith)
Seeing (1 to 5 - best to worst):3
Moon up (phase?):no
Instrument:20" f4.4 Dobsonian
Magnification:X86, X150, X248
Filters used: Lumicon OIII
Object:M76 Litle Dumbell
Category:Planetary
Constellation:Perseus
Object data:mag 12.2 size 140" X 70"
RA/DE: RA 1hr 42.7' Dec 51 34'
Description M76 looks more like a rectangle than a dumbell although
it has a definite waist. Like the Helix nebula the magnitude is very
misleading.
Despite the 12 magnitude this is quite an easy object to spot.
without a filter and at low power, X80, M76 looks like a little pale waisted
rectangle. It's visbility is greatly enhanced with the OIII filter. For some
reason the structure is elusive.
At low magnification all that can be seen is two opposed triangles.
At higher magnification a coarse filamentous structure was glimpsed in the
upper (southern) half of the nebula. This would appear to be the south edge
and a bar across the nebula shown in photographs. The structure was again
elusive. The double triangle and the somewhat brighter end patches were the
most constantly observed features. At each end there was a condensed feature
that looked almost starlike. These were invisible in the unfiltered image.
The fainter nebulosity to the sides of the nebula were just visible.
Through a direct vision prism or a 45 degree prism the nebula only showed a
single image ( presumably the OIII line) in which the starlike features were
particularily conspicuous.
Finding M76: About one degree north to the north of phi Perseus there is a
seventh magnitude star. M76 is in the same low power field as this star to
the left (west).
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| nmartin@bonnyton.u-net.com |
|"There are more things in heaven and earth ... than are dreamt of in your
philosophy" (Hamlet, Act 1, Sc. 5) |
Bonnyton House, Ayrshire,Scotland, UK. lat 55 24'56" N long 4 26' 00" W
Altitude 150 m.
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