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Seattle Brian
sage
Reged: 08/03/07
Posts: 272
Loc: Renton, WA
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Hi Folks,
I'm trying to work my way through Duchek's Planetary Nebulae Telrad book and I'm stuck on the White-Eyed Pea. I must have had it in my field of view on Friday night, but I just couldn't see it. I started at 60x magnification and then bumped it up to x140, but to no avail. I didn't see any fuzzy stars or blue/green colors. I can't find any pictures or suggestions on the Internet and was wondering if anyone could help me out with what it might look like or how you found it, let me know. 
Thanks,
Brian
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Brian
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sgottlieb
sage
Reged: 07/22/07
Posts: 243
Loc: SF Bay area
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Here's the HST image for IC 4593 = White-Eyed Pea. It's a compact planetary (about 10" visually) with a bright central star, so look for a fuzzy blue star. It's very possible you passed right over it, so you might want to try "blinking" the field with an OIII or narrow-band filter (like a UHC). The planetary is located 11' NW of double star Struve 2016 = 8.6/10.0 at 7" and this should pin down the location.
As far as the appearance, here are my most recent notes...
18" (7/20/06): at 160x the 11th magnitude central star is encased by a small, oval halo, elongated NNW-SSE, ~10"x7". The planetary has the characteristic blue glow seen in this class of objects. Good response to OIII blinking at this power. The central star is more prominent at 225x and 325x but there were no additional details visible in fairly poor seeing.
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Steve Gottlieb
18" f/4.3 Starmaster
Adventures In Deep Space - New article on MASH planetaries
7500+ NGC/IC Visual Descriptions
NGC/IC Project
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Seattle Brian
sage
Reged: 08/03/07
Posts: 272
Loc: Renton, WA
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Thanks, Steve. I've noticed that I'm not very good at spotting PN's when sizes get down below 15s - I had a lot of trouble with the Blue Racquetball too. Your notes will really help.
I'll definitely give blinking a try the next time it clears up here - I wasn't using an OIII filter at all on Friday.
Brian
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Brian
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Achernar
Post Laureate
Reged: 02/25/06
Posts: 3720
Loc: Alabama, USA
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If you're looking for IC-4593, which is usually the object also called the White Eyed Pea, you could have missed it. It's very small, and when I found it for the first time it looked like an out of focus star at first. High magnifications are the key to seeing it, and it really does look sorta like a whitish pea too.
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10-inch F/4.5 Discovery Dob
6-inch F/8 Homebuilt Dob
4 1/4-inch F/4 Homebuilt reflector
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MessierScott
super member
Reged: 06/18/07
Posts: 188
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The use of a OIII filter helps greatly when hunting down planetary nebula. Blinking the filter will dim the stars in the field and brighten the PN. This works for "most" PN.
hmmmmmm I seen more of a greenish color myself.
My notes from November 2005 using a 20-inch dob at 210x:
"A central star can be easily seen. No filters are needed to view and it can be seen with direct vision. A OIII filter brings out more detail and makes the nebula “pop out” of the field. Averted vision also greatly increases the apparent size of the disk. Nice round hazy ball with soft edges all around. It has a slight greenish color. There is a bright star just to the northwest and a nice close double just to the southeast."
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Scott Kranz
20-inch f/4.3 Starmaster w/Zambuto mirror, Feathertouch focuser, GO TO & tracking
7-inch Starmaster
H-alpha Coronado PST
Denkmeier II binoviewers w/24mm Panoptics
16x80 binos
Astronomical Society of Kansas City
Astronomical League Messier, Meteor, Sunspotter, & Asteroid Observing Programs Coordinator
ASKC Dark Sky Site
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sgottlieb
sage
Reged: 07/22/07
Posts: 243
Loc: SF Bay area
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Quote:
hmmmmmm I seen more of a greenish color myself.
Regarding blue vs. green -- Here's an interesting experiment next time you look at a bright, colorful planetary in your 20". Compare the color perception using direct vision vs. averted vision and you may find the planetary taking on either color!
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Steve Gottlieb
18" f/4.3 Starmaster
Adventures In Deep Space - New article on MASH planetaries
7500+ NGC/IC Visual Descriptions
NGC/IC Project
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Seattle Brian
sage
Reged: 08/03/07
Posts: 272
Loc: Renton, WA
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Still cloudy here, so I haven't had a chance to give it a retry...
However, I do have a question: If I am only using a 12" scope, will the White-Eyed Pea still have the typical blue or green color (most PN's look baby blue to me)? Taras mentioned that in his 10" it was a whitish color - which is the reason that I was thinking that I didn't spot it.
In either case, I'll try kicking the magnification up a little bit and using an OIII filter. Hopefully one of those stars will look a little fuzzy to me!
Thanks for your help - hunting these things down is a blast!
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Brian
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MessierScott
super member
Reged: 06/18/07
Posts: 188
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Quote:
Quote:
hmmmmmm I seen more of a greenish color myself.
Regarding blue vs. green -- Here's an interesting experiment next time you look at a bright, colorful planetary in your 20". Compare the color perception using direct vision vs. averted vision and you may find the planetary taking on either color!
Thanks! I will have to try that and see what the results are. I remember reading somewhere once also that male vs female will see a different color - don't know how true that is though.
What color do you see in planetary NGC6572? I see green-green-green - almost to the point of John Deere green. Well, maybe not that green, but defintely green.
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Scott Kranz
20-inch f/4.3 Starmaster w/Zambuto mirror, Feathertouch focuser, GO TO & tracking
7-inch Starmaster
H-alpha Coronado PST
Denkmeier II binoviewers w/24mm Panoptics
16x80 binos
Astronomical Society of Kansas City
Astronomical League Messier, Meteor, Sunspotter, & Asteroid Observing Programs Coordinator
ASKC Dark Sky Site
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Seattle Brian
sage
Reged: 08/03/07
Posts: 272
Loc: Renton, WA
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I see it as blue, but not a bright baby blue like I see in the cat's eye or the blinking pn. Interesting. I'll have to give the averted vs. direct vision thing a try as well.
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Brian
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sgottlieb
sage
Reged: 07/22/07
Posts: 243
Loc: SF Bay area
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Quote:
What color do you see in planetary NGC6572? I see green-green-green - almost to the point of John Deere green. Well, maybe not that green, but defintely green.
Well, I can stand in the green-green camp or the green-blue camp. Here's my last observation of NGC 6572 as per earlier comments...
18" (8/2/05): at 225x I noticed an interesting color effect; although the color was a quite prominent bluish-green, while staring at the center the planetary decreased in size and the color changed to a deep emerald green.
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Steve Gottlieb
18" f/4.3 Starmaster
Adventures In Deep Space - New article on MASH planetaries
7500+ NGC/IC Visual Descriptions
NGC/IC Project
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