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(IAAC) Obj: NGC 6914 - Inst: 20" f4.4 Dobsonian Mount
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Observation Poster: Nick Martin <bonnyton@ednet.co.uk>
Observer: Nick Martin
Your skills: Intermediate (some years)
Date/time of observation: 24/25 August 2001 00:00UT
Location of site: Bonnyton House,Ayr,Scotland, UK (Lat 55 25m, Elev 500ft.)
Site classification: Exurban
Sky darkness: 6.0 <Limiting magnitude>
Seeing: III <I-V Seeing Scale (I best)>
Moon presence: None - moon not in sky
Instrument: 20" f4.4 Dobsonian Mount
Magnification: X180
Filter(s): UHC
Object(s): NGC 6914
Category: Emission nebula.
Class:
Constellation: Cyg
Data: mag ? size 6.3'X 4.5'
Position: RA 20:2425 DEC 42:29
Description:
Object Rating: B
This is a faint diffuse nebula, which is a difficult object to observe.
Megastar shows three separate nebulae in this complex, in order of decreasing
declination, NGC6914, 6914B, 6914A. The DSS photograph of the area shows that
these nebulae are part of a complicated mass of nebulosity linked to the vast
IC1318 complex.
NGC6914 is centred around a pair of stars, 11 magnitude GSC 3160:1710 and
11.6 magnitude GSC 3160:1272 which are 52" apart. A short line of stars starting
with 8.7 magnitude BD +42 3743 and ending with 7.2 magnitude BD +42 3740
points south-east to this pair which are roughly the same distance away as
the distance between these stars.
The nebulosity in NGC 6914 is brightest around the pair of stars but is
everywhere faint and best seen with averted vision. It does not seem to conform
well to the outline shown in Megastar. When first seen the nebulosity formed
a roughly elliptical patch. On a clearer night it showed a complex structure
especially on the following edge. There was a dark lane in the nebulosity
preceding the star pair then a narrow linear band of nebula forming the
preceding (western) boundary to the nebulosity, which extended north as far as
9.7 magnitude GSC 3160:1487. This nebulosity is very faint in the DSS picture.
Illogically, the next component downward is 6914B. About 1 minute of arc wide
and shaped like concave half egg, it extends mostly in the preceding direction. There is a brighter patch around the brighter star of the central pair. Its southern edge includes a trio of faint stars.
NGC6914A surrounds the brighter triangle of stars on the preceding edge of the
open cluster DO-8. It extends to between this triangle and the horseshoe shaped
group of stars, which comprise the rest of the cluster. Under clear conditions
faint traces of nebula almost connect 6914A with 6914B.
These objects present an interesting observing challenge. Their visual outlines
show some discrepancies from those shown in Megastar and their brightness
differs from the intensities shown in the DSS field.
Since making these observations a report on the Amastro list has reported good
results using an H-beta filter on the IC 1318 complex.
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