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Spirograph Nebula

IC 418, HD 35914, PK 215-24 1, PN G215.2-24.2, PN VV 22, PN VV' 32, Spirograph Nebula

RA: 05h 27m 28.204s
Dec: −12° 41′ 50.26″

Con: Lepus
Ch: MSA:302, U2:270, SA:11

Ref: SIMBAD

(reference key)

Type: planetary nebula

Mag: B=9.78, V=9.56

Size: ?
PA: ?

Published comments

Terzian, Y. (1980)

Terzian Y (1980) Q.J. R.astr.Soc vol 21, p82-92 [09.16.1] notes that this planetary has been detected in CO emission.

Modern observations

Hartung, E.J. (1968) Astron.Obj.South.Tel

Hartung notes: "This fine object has a bright bluish disk about 12 arcsec across with a bluish central star, round which is a larger faint envelope."

Walter Scott Houston

Houston writes: "Because of its 9th mag central star, this object is reasily located in 7x50 binoculars. The surrounding nebulous ring is about 14 arcseconds across and a bit brighter than 12th mag."

Sanford (1989) Observing the Constellations

Sanford calls it "a small but bright planetary nebula, appearing as a blue disk about 12 arcseconds in diameter, with an 11th magnitude central star."

Tom Lorenzin

Tom Lorenzin, in the electronic version of "1000+ The Amateur Astronomers' Field Guide to Deep Sky Observing", notes: "11.8M; 14" diameter' small, nebulous blob with 9M center star; 500x yields best view."

Brian Skiff

6cm - def vis as a m9 *, not m12. no pn character, *ar. CBL, Roof.

7cm - vdifficult to ident from small-scale atlas (BSA) since it is completely *ar @ 30x. cen * evidently dominates view since UHC & [OIII] provide only sl enhancements. pn is Ern * in lg equilat triangle of m8-9 *s. seeing soft enough that I can't sure of nebular nature even @ 110x. BS, 26Nov1992, Anderson Mesa.

15cm - shows cen *. BS, 26Jan1982, Anderson Mesa.

- m10.5 cen * w/vf haze perhaps 10" diam. m9 * 5' SW, two m12 *s N closer. BS, 15Nov1993, LCO.

25cm - 180x/240x: circ, 20" diam. vbr w/o sfc detail. diffuse margin. looks like fat *, cen * not vis. Roof.

- br and distinguishable at lox, looks "funny". hisfcbr, m8 overall. cen * clear @ 190x, about m12. 10" diam, circ; seems to have losfcbr halo 1'.5 diam. poss pale green. BS, 26Jan1982, Anderson Mesa.

30cm - br; cen * prominent, especially at hix. 220x: eeges not so sharp as at 440x: fairly def edges, elong ~N-S. Roof.

Kaler, James B

James B. Kaler ("The Amateur Scientist", Scientific American, May 1992) notes: "IC 418 is difficult to observe. At first, Kuebler [using a 10-inch] could make out only an odd-looking star, but with persistence he found definite nebulosity."

Steve Coe

Steve Coe, observing with a 13" f/5.6, notes: "Pretty bright, small, round, central star easy at 270X. A very nice greenish glow around the central star. It is small, however, and 100X was just enough to distinguish it from the backround of stars."

IAAC posting: Wed, 20 May 98 15:45:23 -0400: "I observed IC 418 several years ago in my 13" f/5.6. At 100X it was just barely recognized as non-stellar. Going to 270X I called it: pretty bright, small, round and the central star was easy. At high power it was a nice greenish glow around an easy central star. This planetary does have pretty high surface brightness."

Murrell, Andrew (IAAC)

Your skills: Advanced (many years) Date/time of observation: Location of site: Ilford NSW Australia (Lat , Elev ) Site classification: Rural Sky darkness: 6.5 Limiting magnitude Seeing: 7 1-10 Seeing Scale (10 best) Moon presence: None - moon not in sky Instrument: 20" f5 dobsonian Magnification: 160-350 Filter(s): none Object(s): IC418 Category: Planetary nebula. Class: Constellation: lepus Data: mag 9.3 size 12" Position: RA 05:27.5 DEC -12:42

Description: IC418 is a compact planetary that appears quite unusual through a large scope. The planetary has a distinct red colour. The cluster appears to be about 30" diameter, and has a very bright central star at 10.17 magnitude. Direct vision gives the planetary an annular appearence and a pale crimson shading. Averted vision changes the view slightly as the planetary has an even surface brightness and appears to change clour to pale aqua. The central star dominates the view. The outer edge of the planetary is the brightestand the nebula is visible as a star in my 90mm finder. I did not use a filter to observe the planetary as I have found that it does not improve the view of the object. THIS is a MUST see planetary

[amastro] posting

Barbara said (don't we have a bunch of nice people on this list? :-))

] Hi Brian:

] Your statement above, made me think of the distinct reddish

] IC 418 planetary, which to my eyes shows this color better

] than any planetary I have observed.

]

] Certainly there is no need to include anything blueward of H-gamma,

] nor redward of 5007A except for the few (maybe five) objects bright

] enough for H-alpha to matter.

]

] Could you elaborate on the few objects you think H alpha would

] matter on?

]

] Barbara Wilson

Yes, IC 418, which I like to call, "the Pink Planetary" (music: "PINK PANTHER theme..) should definitely be looked at in terms of its spectrum. I liken its color to the color milk takes on when you put in the first few spoonfuls of Nestlie's Strawberry Quick. As far as other objects which show some H-alpha, I think the two obvious ones are M42 and M8, although to really "see" the reddish hints, the "new" version of Lumicon's OIII filter with the booming red "leak" passband is best (some early versions, and possibly the new Thousand Oaks OIII did not have much of a red passband). Doing rapid comparisons between the UHC and OIII using Lumicon's multi-filter adapter really makes the reddish color obvious. IC 418 must be younger or have something odd going on to get that H-alpha mode going as strong as it appears. I have heard of young eyes (younger than mine) seeing red in M20 with larger apertures. I will have to try a few objects with my filter adapter at NSP. Clear skies to you. --

David Knisely KA0CZC dk84538@navix.net

Prairie Astronomy Club, Inc. http://www.4w.com/pac

Hyde Memorial Observatory, http://www.blackstarpress.com/arin/hyde

************************************************

* Attend the 6th Annual NEBRASKA STAR PARTY *

* August 7-14th, 1999 http://www.4w.com/nsp *

************************************************

------------------------------------------------------------------------

I wrote an article about the color in IC418, which was published in AA Vol.14, the summer addition of 1997, on page 4, for those of you who are interested in the scope sizes and location of observations. Interestingly, I have AND have not been able to see the color in my 36" at High Knoll Observatory, located outside of Sierra Vista, Az. That would lead me to suspect that primary size AND transparancy play a part in seeing the color.

On the night of the published observation, Jay LaBlanc described the color as red, while I described it as crimson....such is the world of semantics. Neal

------------------------------------------------------------------------

I must apologize to Barbara and David for my doubts. It turns out that the light with spectrum of the planetary nebula IC 418 (its gas) is expected to be pink even to the Standard Observer defined by CIE (Commission Internationale de l'Eclaire - International Commission On Illumination) in 1931. CIE is the official authority in colorimetry and photometry, something like IAU (International Astronomical Union) in astronomy. Using the CIE 1931 color matching functions, I calculated the color (more precisely the chromacity coordinates x and y) for the spectrum of IC 418 as listed by Hyung et al. 1994, PASP 106:745 (quoted in ELCAT): x = 0.431, y = 0.310. Then I used the DOS program CVD (Color Vision Demonstrations) by Hans Irtel of the University of Mannheim to display this color. You can look at the screenshot at

http://www.bm.cesnet.cz/~ondra/ic418cie.jpg

The color is that of the square to the right (the x and y values are slightly different, but this doesn't matter). Naturally, you must have monitor with high color resolution (more than 256 colors). Even so, there are differences in way different monitors, platforms and software display colors, the color may also be less saturated or brighter (closer to white), but IC 418 is definitely reddish.

More pink planetaries, Leos

------------------------------------------------------------------------

Hi All

I tried an experiment with IC 418 at the 1997 Winter Star Party. Four people were asked to describe the color of the planetary - two could see a red ring and two could see a green one - although it was difficult to tell if this related to observing experience or different color reponse in low light. I saw the color would change depending if direct or averted vision was used. I could see a distinct red ring with my 18"f/5 at low powers ( 35mm and 20mm ) but the color became diluted - but still red - at 260X. Ken Drake best described the color as "beet" red.

The Atlanta Astronomy Club's 20" f/4.5 reveals a greenish disc at high power in fairly stable seeing - although this was at high power and an [OIII] filter. If the color is seeing or aperture dependent makes for an interesting project...

Campbell's Star in Cygnus (PN G 64.7+5.0) also exhibits a distinct red ring in a 24" reflector. Both IC 418 and Campbell's star have strong H-Alpha emissions - which leads to the question: do all high surface brightness planetaries with strong H-Alpha emissions appear red?

Dave Riddle

------------------------------------------------------------------------

Leos,

I am NOT surprised you were doubtful, as so many were when I came back to Texas from the Winter Star Party in 1994 raving about this red planetary (It WAS red in portions of its outer most parts in Tom Clark's 36" f 5. Everyone down in south Florida was pretty ho hum about it, and took the coloration for granted.

Obviously, Dave Knisely sees colors quite well, and his description of the color of IC418 closely matches my observations from Texas.

Me, I was shocked to see this most vivid color in a type of object that usually exhibit green or blue green hues. I sent a letter to the Webb Society via Owen Brazell about the color of IC 418.

Every visual observing manual on planetaries I researched, from old Deep Sky Issues to S & T, to the Webb Society book on planetaries had visual observations of this planetary but, with NO indication of red or pink coloration. I asked myself WHY? Then Jose Sancho and I did a test with various apertures and under various seeing conditions.

As a result I am now convinced that sub arc second seeing is imperative for VIVID visual coloration to be imparted to the human eye.

The seeing conditions in Florida were superb even though the transparency was not spectacular.

Here in Texas (in winter) the seeing is not very good. 2-3 arc seconds to 5 or more being the norm on a typical evening. The pinkish coloration was obvious to both Jose and I during our tests, but the really vivid reddish colors in IC418 that I saw from Florida in a number of different apertures was most impressive, and I have not seen them from here. --

Barbara Wilson

bwilson2@ix.netcom.com

http://www.hmns.org/hmns/george/globular.html

------------------------------------------------------------------------

I found the letter I wrote to Owen on IC 418:

To Owen Brazell, Webb Society Editor

The Deep Sky Observer

From Barbara Wilson

Webb Society Member

Houston, Texas

Dear Owen:

In Deep Sky Observer 7 (Oct 95) pg 6 a letter from George de Lange seems to be in response to observations I made which appeared in Deep Sky Observer 5 (Oct 94) page 5; "Colour in IC 418". In this article you asked for other observations of IC 418 as "no other planetary appears to show red coloration."

George de Lange's letter indicates that he, Robert Erdmann and Steve Coe observed IC 418 to see if they could distinguish a red color, and they responded that they could not. Later in the letter they hypothesize that maybe some observers could have mistaken IC 418 with two SAO stars nearby, since these stars show a slight red color.

I am writing in response to the above and to illuminate my own and other observer's observations (who have seen color in IC 418) here in the US.

First, I can assure the writers that I nor others had mistaken the SAO stars for IC418. The SAO stars are plainly visible in a low power field as stars, where IC 418 has a distinct non stellar doughnut shaped appearance.

Observational History

I was first introduced to this planetary at the Winter Star Party in February 1994, when shown this object in a fine 20" f/6 by Tom Lorenzin and Vic Menard (scope owner). Tom and Vic showed it to me because this object is a WSP favorite because of it's red coloration. I was so surprised to see red coloration, I couldn't believe my eyes at first.

Tom Clark then immediately showed me IC418 in his 36" f/5. The color impact was stronger in this telescope. At medium power (200), detail in the ring's outer sharp rim, showed strong red color. In the inner rim (distinct separate wisps) several portions are redder and other parts are rosy pink red.

I also went to other telescopes (Jim Walker's 17.5") to see if this color was visible in smaller apertures. The color was still very strong in Jim's and he was also surprised to see this unusual color. I having never seen such a strong red color in a planetary or any other deep sky object, became captivated by it and wondered why this had never been documented in ANY observing book I have read. I wondered if it was a consequence of the exquisite sub arc second seeing conditions that are famed at this star party?

When I returned home to Houston, I contacted several trusted observing friends (Jose Sancho and Ken Drake) and asked them to observe this object. I did not in any way biase their observations, I just asked them to look for color and report what they saw. Neither person had ever observed IC 418 before.

Jose Sancho was the first person to report back. He immediately saw the reddish color in his 18" on February 15, 1994 near the end of astronomical twilight, with a almost first quarter moon, using a 20 Nagler which gives his 18" 100 power. He saw a very small disk with a light red coloration on the outer edge of the disk. He then used a 12 Nagler (170X) and could still see a pink color, then with a 9mm Nagler at 220X it was a much lighter pink. Then he called me to report his observation. It was then obvious that sub arc second seeing was not a prerequisite to seeing the red color.

Kenneth Drake also observed it much later and his report follows mine.

Jose and I checked every source book we could find; Old Deep Sky magazine articles, Observer's Guides, Luginbuhl and Skiff, Webb Society Book 2, Steven J. Hynes' Planetary Nebulae, Burnham's Celestial Handbook. We did not find any observations to indicate any variance to the classical blue green color that most planetaries appear to display. But obviously this planetary exhibits strong H alpha emmission since the color is so apparent.

Why has this apparent color not been documented. I suspect it is because since the planetary is so small most observers view it at high power, which diminishes its color. The implication here is to observe the planetary at lower powers to see it's color. Tom's 36" is hardly powered at 200 so the color remains strong.

Most of us who observed the red color in IC 418 thought this was an old story, case closed until the letter appeared in Deep Sky Observer 7.

In fact, Bob Fowler with the Amarillo Astronomy Club (as reported in their club newsletter) also observed IC 418 about a year ago with a 20" owned by Bill Canady. Bob was the first to notice the red rosy color and called over several younger observers (Bob is in his 70's) and most of them could see the reddish color. Bob indicated that the color stayed consistent as they observed it numerous times throughout the evening.

Observing color is somewhat subjective. I have been able to see color in many deep sky objects. I have seen what I call the Rainbow Shock Front in the Orion Nebula. It changes from a pale greenish to yellowish to orangish to reddish in a 25". I have seen some planetaries exhibit emerald green color. I have seen what I call a poison green color (like a tree frog). Once I saw a violet color, in a planetary. But to date, IC 418 is the only red planetary I have seen.

Barbara Wilson

Houston, Texas.

------------------------------------------------------------------------

Barabara Wilson tells me that someone at the Webb Society needs a little help with a visual impression of IC418. I had never looked at it prior to this time. It was October 7th 1994 and I was at a small west Texas star party with a group of friends. I was getting tired and about ready to put things away when I remembered being told to take a look at IC 418 to see if I could see anything strange. I was standing there looking up at Orion when I recalled it being only a short ways south of the bottom of Orion (7.5 deg. south of M42). All I had been told is that it was a Planetary nebula and was very unusual. I found it on the U-2 chart and pointed my 10" f/5.6 scope at it. It took a moment to locate its place in the star-field and then a few more seconds to see it in the 68x field. You may be asking how I remember all these details. Stunning! Truely stunning! That's how. This object will never be forgotten if seen under the right circumstances. It's perfectly round, has very sharp edges, and is beet red. Make that crimson red with a small hollow spot at center and a prominent central star. CRIMSON RED! Also the disc appears to have grooves in it like a phonograph record. Here's the kicker. It's a small planetary (12") and as I increased power to 113, the color changed to a very pale green. At 138x and above it lost all color and went to grey. The central star was white at all powers. The explanation for this is surely surface brightness increasing with lower powers. I later made a list of other planetaries that have similar size/brightness profiles but have yet not seen any like this. I'll post the list later. Noow is a good time to check this out because it transits about 9 PM local time.

Good luck,

Kenneth Drake

----------------------------

Andrew,

I saw IC 418 for the first time at the 1995 Winter Star Party through Ed Boutwell's filtered 24" Dob and was suitably impressed with its unique color and central star. I fully concur that it is a must see.

Dave Mitsky

------------------------------------------------------------------------

Here are some observations of IC 418. Neal's correct when he said I got excited when I first viewed this one, I nearly fell off the ladder. (Good thing it was at low elevation!)

#2187 12/07/96 SCOPE 32 4 6 HIGH KNOLL

20N (183x) Spectacular small PLA with a very bright blue central star surrounded by a copper colored sharp edged nearly circular uniform annulus. Quite dark inside the ring, next to the central star.

#3532 01/24/98 SCOPE 17.5 ALTAZ 4 4 SONOITA

35P ( 57x) Quite small at this power, a fuzzy looking blue star with a tiny red ring surrounding it, the color just detectable.

20N ( 99x) About the same, the color is subtle but clearly red. The feature appears to darken around the central star.

#5468 11/16/98 SCOPE 17.5 ALTAZ 4 7 SONOITA

13N (153x) Quite a lovely PLA, excellent view at this power with blue central star and a sharp edged reddish edged slightly oval disk. Looks darker immediately around the star.

#5469 11/16/98 SCOPE 32 4 7 SONOITA

20N (183x) Red color more easily seen than in the 17-in. The dark space around the star seems smaller.

-Jay-

------------------------------------------------------------------------

Hi Barbra;

I have a question about this fascinating object, why do you think that good seeing is necessary for the pink color to be prominent? Texans and Arizonans have both learned to get the best from a night with seeing better than 2 arcsec or so. Mostly because, for us, that is a pretty rare night. However, I will certainly put this little guy on my observing list for Fall + Winter. If I get a great night I will give it a try.

So, I don't understand how seeing would effect the color balance of an object. How can the percentage of the total light from an object be altered by atmospheric movement? How can movement of the atoms and molecules in the air selectively disperse some colors?

I have observed this object with both my 13" f/5.6 and Bob Erdmann's 16" f/5 and never seen any color other than light green. But, now I am motivated to look again. Also, several members of the Saguaro Astronomy Club have purchased larger scopes (20 and 24 inchers) and will see if I can have them take a look at a club star party this Winter.

Fun stuff; Steve Coe

------------------------------------------------------------------------

Steve wrote:

] Hi Barbra;

]

] I have a question about this fascinating object, why do

:

] I get a great night I will give it a try.

Steve, From experiments with this object, I found that the less "smearing" by the atmosphere due to scintillation the better the color rendition to the eye. The night I first observed IC 418 in Florida at the WSP 94, the seeing was superb, less than 1 arc sec.

In fact almost every object I looked at that night showed color if it was a high surface brightness object.

I saw 5 reddish stars near the center of Omega Centauri. You might think that was due to its low declination. However I had never seen these reddish stars from my normal observing location where it was 5 degrees lower in the sky.

] So, I don't understand how seeing would effect the

:

] in the air selectively disperse some colors?

I am assuming here that what affected the color balance from Texas was the "smearing" of the color, ie the light not being as concentrated in a smaller area, to really excite the cones in ones eye. I am no expert at all on this just speculating based on a number of observations, over the years. I have seen incredible color on Jupiter before, bluish-violet colors, but again this was from WSP, with sub arc second seeing.

]

] I have observed this object with both my 13" f/5.6 and

:

] Winter.

Please let me know what your results are, and in particular what the seeing conditions were?

--

Barbara Wilson

bwilson2@ix.netcom.com

http://www.hmns.org/hmns/george/globular.html

------------------------------------------------------------------------

Birkmann, Mark G. (IAAC)

Observer: Mark G.Birkmann Your skills: Intermediate (some years) Date/time of observation: 10/13/99 Location of site: New Haven, Missouri (Lat ~38, Elev ~700') Site classification: Rural Sky darkness: 5 1-10 Scale (10 best) Seeing: 6 1-10 Seeing Scale (10 best) Moon presence: None - moon not in sky Instrument: 40" f/5 dob Magnification: lowest power 125x Filter(s): OIII, H-beta, Orion Ultrablock Object(s): IC 418 Category: Planetary nebula. Class: 4 Constellation: Lep Data: mag 10.7 size 12", central star mag. 10.1 Position: RA 05h:27m 28s DEC -12:41' 50"

Description: This small planetary showed a thin inner ring of light blue nebulousity equal in thickness to about one half the diameter of the bright central star. The outer ring was equal in thickness to the diameter of the central star, was an obvious red color, and was immediately adjacent to the inner ring. The border between the two rings was not sharply demarcated. Rather, the blue ring faded into the red ring over a short distance. The red was not seen above 250x. A drawing can be seen at: http://www.fortunecity.com/greenfield/twyford/637/drawings.planetaries.htm

Yann Pothier (IAAC)

Observer: Yann POTHIER (France) Your skill: advanced (many years) Object: IC 418 (PK 215-24.1; PN G215.2-24.2; ARO 3) Category: planetary nebula Constellation: LEP Object data: Vmag=9.32; Bmag=10.7; 14"x11"; type IV; central star of Vmag=10.17; discovered by Fleming in 1891; ELCAT: [OIII, 496+501nm] = 1 x [Hbeta, 486nm] !!!. RA/DE: 05h27.5m, -1242' (2000) Date and UT of observation: 23 December 1997, 23h30 UT Location & latitude: La Clapiere Obs. (France, latN44 40 00, longE06 27 36) Site classification: rural, alt.1650m (5500ft) Limiting magnitude (visual in UMi): 6.4 with averted vision (20% of the time) Transparency (1 to 5 - best to worst): 1 Seeing (1 to 5 - best to worst): 3.5 (stellar stars until 125x) Moon up (phase?): no Instrument: Coulter 445mm/17.5" F/4.5 Magnification: 400x Filters used: UHC, OIII, Hbeta

Description: at 400x and OIII, small PN, bright and round with quite sharp edges, homogeneous; estimated diameter of about 19"; the OIII filter makes the nebula bigger; UHC has a good contrast gain, OIII a very good one and Hbeta (for once) has a good one too [thanks to the tremendeous Hbeta flux of this PN].

Observer: Yann POTHIER (France) Your skill: advanced (many years) Object: IC 418 (PK 215-24.1; PN G215.2-24.2; ARO 3) Category: planetary nebula Constellation: LEP Object data: Vmag=9.32; Bmag=10.7; 14"x11"; type IV; central star of Vmag=10.17; discovered by Fleming in 1891; ELCAT: [OIII, 496+501nm] = 1 x [Hbeta, 486nm] !!!. RA/DE: 05h27.5m, -1242' (2000) Date and UT of observation: 20 November 1998, 23h00 UT Location & latitude: Bellou-le-Trichard (France, latN4816'08", longE 0032'50") Site classification: rural, alt.250m Limiting magnitude (visual in UMi): 6.31 with averted vision (10% of the time) Transparency (1 to 5 - best to worst): 1 Seeing (1 to 5 - best to worst): 1 (stellar stars until above 500x) Moon up (phase?): no Instrument: 22"/560mm F/3.9 (Torus optics) Magnification: 629x Filters used: none

Description: at 629x, delicate annular PN, elliptical, with a distinct pinkish-reddish hue, faint central star (maybe mag13) which seems yellow by contrast with the PN color [with no doubt, this reddish color is caused by the faint OIII and Hbeta fluxes compared to Halpha's: Ha = 4 x Hb].

Observer: Yann POTHIER (France)

Your skill: advanced (many years)

Object: IC 418 (PK 215-24.1; PN G215.2-24.2; ARO 3)

Object data: Vmag=9.32; Bmag=10.7; 14"x11"; type IV; central star of

Vmag=10.17; discovered by Fleming in 1891; ELCAT: [OIII, 496+501nm] = 1 x

[Hbeta, 486nm] !!!.

RA/DE: 05h27.5m, -1242' (2000)

Date and UT of observation: 03 Janvier 1991, late evening but before moon rise

Location & latitude: La Clapiere Obs. (France, latN44 40 00, longE06 27 36)

Site classification: rural, alt.1650m (5500ft)

Limiting magnitude (visual in UMi): 6.0 with averted vision

Transparency (1 to 5 - best to worst): 1

Seeing (1 to 5 - best to worst): ?

Moon up (phase?): no (18th day)

Instrument: Japanese 4.25" F/7.8

Magnification: 36-180x

Filters used: no, visual spectroscope

Description: located easily with prism at 36x like a thin continuous spectrum (central star) crossing a stellar knot (nebula), quite bright; without prism, small PN, nebulous with central star quite distinct surrounded by a tiny nebulous atmosphere; at 72x, larger with easier central star, bluish (?) and the sepctroscope reveal two OIII images [corrected afterwards: it must be the Hbeta and OIII -at 501nm- images that separates; see observation with 22-inch scope for more detail on the spectroscopic peculiarities of this object]; the image is the same until 180x, a nice central star surrounded by a regular but small nebulous enveloppe.

Paul Alsing

82-inch at McDonald - Observing Report

[amastro] posting, Sat Nov 25, 2006

82" telescope, McDonald Observatory near Fort Davis, Texas, USA

f/13.7, 35mm Televue Panoptic (5' fov, 812x)

This smallish PNe is said to have a red rim. When I first put eye to eyepiece this red rim was obvious, but after just a few seconds the red almost completely disappeared! If I closed my eye for several seconds, it came back for a moment or 2. Anyone have an explanation? Otherwise, this is a bright planetary with a bright CS. The interior was not exactly smooth, but not exactly detailed, either, very hard to describe. I guess that the word "mottled" works here. It seemed to me to have an overall color, but it was difficult to tell exactly what that color was... hmmm... a very curious object.

Bill Ferris

Gyulbudaghian's Nebula and other Deep Sky Treats

[amastro] posting, Tue Nov 8, 2005 4:37 pm

Anderson Mesa

This is one object that makes me wish I drew in color. IC 418 is centered in my sketch. The drawing captures a 272X view in the 18- inch. The most stunning feature of this tiny planetary is its distinctive raspberry hue. This defining characteristic has led some amateurs to nickname IC 418 the "Raspberry Nebula," and that's all right with me. Under direct scrutiny, the nebulosity flashes its technicolor best then slowly dissolves to invisibility. With averted vision, the nebula returns to its full--albeit colorless--form. The 12" diameter nebula enwraps a 10th magnitude central star. Another 16 stars dot the field in my drawing, most of which are 14th or 15th magnitude in brightness.

Contemporary observations

Magda Streicher

2006 September 21

Pietersburg

16-inch f/10 SCT (101.6x, 127x, 290x)

One of the best planetary Nebula in contrast with an outstanding blue green shade of color. Middle star shines frosted blue on a soft see through hazy surface. A outer ring that glows around the star like a halo for almost 10". The north-western side is slightly more hazy. With high magnification (16" - 290x) it show the lovely halo, with even higher power (16" - 346x) the objects show a slightly flatten disk. The diamater is maybe slightly more than 20".

2006 November 18

Alldays

12-inch f/10 SCT (76x, 218x, 346x)

Conditions: Good

Most beautiful metallic blue planetary show off the blinking effect. A bulb impression with a little peep halo shining through a misty hole. Very small planetary but very much alive. Higher power show a star of about 10-magnitude yellow star with a somewhat larger impression of the nebula. A round nebula well edged although frosted.

Richard Ford

2011 March, 26th Saturday

Location:Night Sky,Bonnievale.

Instrument:12-inch Dobsonian Reflector Telescope.

Sky Conditions:Whole Milky Way is visible.

Transparency of the Sky:The sky is clean.

Seeing:Atmosphere stable with little interference.

Limiting Magnitude.

I.C.418

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Object Type:Planetary Nebula.

First Impression:This object looks like an out of focus star.

Location:Lepus.

Time:8:41pm.

Chart Number:No.95(Extract taken out of "Star Gazer's Deep Space Atlas").

Size:9mm Eyepiece:Field Of View:15'/13=1.1'.

7mm Eyepiece:Field Of View:15'/12.5=1.2'.

1.1'+ 1.2'=2.3'.

2.3'/2=1.1'.

Size in Arc Minutes:1.1'.

Ratio:1:2.

Major Axis:1.1'.

1.1'/2=0.5'.

Minor Axis:0.5'.

Planetary Nebula is 1.1'* 0.5'.

Brightness:Magnitude 11.

Brightness Profile:The whole planetary nebula towards the nucleus grows brighter in the centre.

Challenge Rating:Fairly Difficult.

Description

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This nebula is a fairly large round object both at 167* and 214*.This nebula is seen as a medium out of focus star which looks almost like a snowball.I.C. 418 has a blue-green surface structure.

Tom Bryant

2010 11 13 4:5:59

Observing site: Little Tycho Observatory

Telescope: C-8

[5h 27m 30s, -12 42' 0"] A small (10"), bright, round 9mv planetary. It was best in the 6mm, and the central star was glimpsed.

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