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Re: (IAAC) Obj: The Homunculus - Inst: 20" f5 Dobsonian



Andrew Murrell schrieb:
> ----
>
> Observer: Andrew Murrell 
> Your skills: Advanced (many years)
> Date/time of observation: 
> Location of site: Ilford  NSW Australia (Lat , Elev )
> Site classification: Rural
> Sky darkness: 6.5 <1-10 Scale (10 best)>
> Seeing: 8-9.5 <1-10 Seeing Scale (10 best)>
> Moon presence: None - moon not in sky
> Instrument: 20" f5 Dobsonian
> Magnification: 160-700
> Filter(s): none
> Object(s): The Homunculus
> Category: Planetary nebula. Emission nebula.
> Class: stellar ejecta
> Constellation: carina
> Data: mag 6.5  size 30"
> Position: RA 10:45.1  DEC -59:41
> Description:
> The Homunculus is the small nebulae that surrounds Eta Carina. It is the
>  envelope 
> of stellar material that was ejected from the star about a century ago. This
>  is the
> only nebulae that shows an obvious colour, Bright orange. This colour is very
> striking against the star background. The initial observation was at 160x.
>  This shows
> the surrounding keyhole nebulae NGC3372, which defies description. The
>  Homunculus
> appears as a peanut shaped orange blob about 30" across. At 300x it appears
>  as a bright 
> hazy star with a lobe or bubble of material on either side, orietated SW-NE.
>  The lobe 
> to the SW is the brightest, and appears granular with a dark lane running
>  throughthe 
> middle which curls to the southat the end. The NE lobe is fainter and shows
>  no internal detail
> The center star is about 6.5 magnitude and has a jet progecting to the north
>  about 5" long.
> Averted vision at this power intensifies the colour and shows a bright knot
>  5" WSW of the star 
> in the SW lobe. By increasing the magnifaction to 720x even more detail was
>  glimpsed. In moments 
> of perfect seeing the granulation in the NE lobe became apparent. The bright
>  knot became visible 
> with direct vision,and the colour remained. The dark lane seen before in the
>  SW lobe lost some of 
> its structure, looking more difuse and ending in a small dark hole positioned
>  about 5" from the southern
> edge of the nebulae. The higher magnifaction increased the contrast. The edge
>  of the nebulae remained 
> sharp across the entire perimeter and the arm or jet was easily picked up.
>  What became most noticable
> about the homunculus was the FAINT halo that surrounded the entire object and
>  doubled its size.
> The difuse glow had an indistinct edge and appeared evenly distributed about
>  the object. No intermal 
> details were seen in this faint envelope 
>  A right angle of 15th magnitude stars are positioned about 15" NW of the
>  central star adding to the 
> view at this power. As a side note to this observation stars of 4th magnitude
>  and brighter had difraction
> rings visible, one complete ring and two partial. The seeing was the best in
>  several years that I had seen 
> Reducing the magnifaction to 300x I looked for the faint halo but it would
>  not reveal itself, probably due 
> to the glare from the star and the nebulae. 
>  This goes down as one of the TOP 5 objects in the entire sky.
> --
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+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Hi Andrew! 
Very nice observation report. I will never see such objects with my 20incher here 
from Germany...
With kind regards from Germany, Jens
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