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(IAAC) Obj: IC 418 - Inst: TV-102 (102mm f/8.6 APO refractor)
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Observation Poster: Ron B[ee] <ronby@home.com>
Observer: Ron B[ee]
Your skills: Intermediate (some years)
Date/time of observation: 01/04/02 11:30PST
Location of site: 117h 9m W (Lat 32h 43m N, Elev 2000 ft)
Site classification: Exurban
Sky darkness: 4.5 <Limiting magnitude>
Seeing: 7 <1-10 Seeing Scale (10 best)>
Moon presence: None - moon not in sky
Instrument: TV-102 (102mm f/8.6 APO refractor)
Magnification: 30x, 60x, 110x, 146x, 220x, 293x
Filter(s): none
Object(s): IC 418
Category: Planetary nebula.
Class:
Constellation: Lep
Data: mag 10.7 size 14" x 11"
Position: RA : DEC :
Description:
There was some breeze tonight. I admit that the name "Raspberry Planetary"
intrigued me when I first added IC 418 PN to my list.
At 30x and 60x, it was only stellar. Although I'm not 100% certain,
it sure looked somewhat like a very mild red star, especially when
I compared it to the two reddish/orange stars nearby: SAO 150427 (I
use this one to focus) and SAO 150440. The view changed dramatically
after I slipped in my PN killer eyepiece (8mm TV Radian) at 110x.
It then was detectable as non-stellar, but lost its mild reddish
color! BTW, this PN is only 14" teeny. What a difference
magnification makes! At 146x (6mm TV Radian), it's *definitely*
a planetary nebula with bright 10.2th magnitude central star.
However, I don't see red, but a fairly bright greenish gray glow
around the central star. Brightness of the glow and central star
is retained even at 220x (4mm Radian), still greenish gray. Ah,
but the view would have been best at 293x (3mm Radian) if it wasn't
for the darn breeze :-(. My research showed that observer with
large aperture can see pink or red in this PN, thus the raspberry
name, but not so through the TV-102 light cup. BTW, what's the
minimum light bucket to see pink/red? Consulting with the old
masters, Walter Scott Houston, he apparently did not mention any
red color through his 10" reflector or his 4" RF reflector! Ah,
so the light cup didn't do too badly ;-). It looked very much like
this image I found through the light cup, just not as large or as
intense.
http://www.blackskies.com/images10c.htm
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