| Extraordinary
Efforts And Results!
Observation
Report of GJJC1 By Dennis Means Observation
Report of GJJC1 By Eric Honeycutt Observation
Report of GJJC1 By Jay Reynolds Freeman Observation
Report of GJJC1 By Kent Observation Report (May
2000) of GJJC1 By Observation Report (September
1999) of GJJC1 by Observation Report of GJJC1 By |
||
| GRAPHICAL HOME PAGE |
||
| Near the heart of this magnificant globular cluster
lies a very unusual planetary nebula first noted as a strong infrared radiation source in the IRAS
catalog of 1985. The purpose of this web page is to provide some background information on this PNe and also
supply enough information so that observers with the appropiate telescopic equipment along
with the passion to search out seemingly impossible objects can get a 'hand-hold' on just exactly what they are looking for and where. We lead off this quest with an article written by Rich Jakiel, who often seeks the ultimate in deep sky challenges, and often succeeds! |
![]() |
The following information has been extracted from
a longer article entitled "Seven Ultimate Challenges" written by Rich Jakiel,
which can be found on the web site of Jim Shields (Adventures In Deep Space).
I have embedded some updated information within the text that I have obtained from other
web sites.
The 7th Ultimate Challenge. Planetary Nebula PK 009-07 1 (J2000.0: 18h 36m 22.82s -23d 55m 18.3s)
If any object is impossible to see, this small
planetary nebula comes close! Located deep in the heart of the great globular cluster M22,
this object has defied every observing attempt. And yet, there may be some hope. This most
unusual planetary nebula was first recorded in the IRAS Point Source Catalogue (1985). It
is a member of a rare class of halo planetary nebulae and bears certain similarities with
Pease 1 (K 648) the only other PN in a globular cluster. (Doug's
note: there are now at least 4 known PNe's within globular clusters - Pease1, GJJC1, and one each
in NGC6441 and PAL 6) This peculiar object lacks the characteristic H and He
emission lines, with only [O III] and [Ne III] present (1991, ApJ 379 168 ). There is a
substantial amount of dust accounting for the distinct infrared emission.
UPDATED JULY 10, 2005,
Courtesy of Brian Skiff at Lowell Observatory: "...standardized photometry. The cluster was studied by Monaco et al
(2004MNRAS.349.1278M), who provided BVI data for 186,000 stars in the cluster. They give RA/Dec for the stars, so once the precise position
is in hand, then it was easy to look it up. The data imply that they resolved the northern/southern components of the planetary. They give:
V = 14.67 (N) and 14.53 (S). Assuming there is no bleeding of flux between these determinations, I get a sum of V = 13.8 for the combined
light. The bright background of the cluster is surely the reason it is a difficult object visually, but the implication here is that it is
quite a bit brighter than everyone seems to be assuming. This magnitude seems to be consistent with the I-band magnitude, which is 12.4 as measured
both by Monaco et al and the completely independent DENIS near-IR survey."
Measuring 10" x 7", the PN forms part of an
optical triplet only 1' (arc-minute) from the core of M22.
Before attempting this object, try Pease 1 in
M15. It is visually at 13th magnitude and located several arc-minutes north of the
globular's core center. Alister Ling (1990, Deep Sky 32 36) gives a good write-up on how
he finally succeeded in locating this PN. (Doug's note: There is a Pease1 page on this site with finder charts.)
Unfortunately, our little PN in M22 is a much more difficult customer. Many serious
observers have attempted with apertures up to 25-inches with NO success. I have tried this
several times, the last at the Chiefland Starfest in 1996. Using a detailed finder
chart of M22 and Vic Menard's superb 20-inch f/6.2 dobsonian we gave it our best for
almost an hour. Using magnifications over 400x, and an O III filter we just could not pick
out this PN from the haze of unresolved stars in the core. And that's the paradox. Its
emission is the strongest in [O III] lines, but this type of filter is best used at
lower magnifications. However, to separate the nebula from the extremely dense stellar
background high power is required. The O III filter "mushes" out the very faint
stars turning it into a diffuse background haze. Perhaps a very large scope ( >
30-inches), coupled with very dark and steady skies an observer may be able to ferret this
nebula. A sliding filter bar with both UHC and O III filters would be an invaluable tool.
THE BELOW INFORMATION WAS OBTAINED FROM THE ADS SERVICE FOR DeNIS ON THIS PNe:
THE PN G DESIGNATION IS PN G009.8-07.5 and the IRAS DESIGNATION IS 18333-2357.
Title: The optical/infrared counterpart(s) of IRAS 18333-2357
Authors: GILLETT, F. C.; JACOBY, G. H.; JOYCE, R. R.; COHEN, J. G.; NEUGEBAUER, G.;
SOIFER, B. T.; NAKAJIMA, T.; MATTHEWS, K.
Affiliation: AC(Kitt Peak National Observatory, Tucson, AZ) AE(Palomar Observatory,
Pasadena, CA)
Journal: Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 338, March 15, 1989, p.
862-874.
Publication Date: 03/1989 Category: Astrophysics Origin: STI
NASA/STI Keywords:
BLUE STARS, GLOBULAR CLUSTERS, INFRARED SOURCES (ASTRONOMY), PLANETARY NEBULAE, RED GIANT
STARS, ABSORPTION SPECTRA, ABUNDANCE, EMISSION SPECTRA, INFRARED ASTRONOMY SATELLITE,
IONIZED GASES, STELLAR SPECTROPHOTOMETRY
Bibliographic Code: 1989ApJ...338..862G
Abstract
Observations of the potential optical counterparts of the unusual source IRAS 18333-2357
are reported. There are three distinct optical objects located within roughly 2 arcsec of
the IR source: a red star, a very blue star, and an extended emission line nebulosity.
IRAS 18333-2357 indeed appears to be physically associated with the Galactic globular
cluster M22, and while it probably should be considered a PN, its very small nebular mass
and extreme abundance anomalies are very unusual among known PNe. IRAS 18333-2357 does not
appear to be at an early stage of PN evolution, but instead may be in a late stage. The
lack of an associated radio or H-alpha source is the result of abundance anomalies in the
source.
It should be brought to your attention that the following page may take considerable time to load. There are a few images which are over 20KB each, and the page may take over a minute to load.
AND NOW, ONTO THE FINDER CHARTS AND IMAGES ![]()
Dennis Means Observation Report on GJJC1
I would like to report a positive observation of GJJC1 in M22.
The telescope used was Steward Observatory 90" Bok telescope on Kitt Peak. The focal ratio was f/9 giving a 20624mm focal length. I
used two eyepieces. A Rini 34mm Modified Plossl at 606x and a Russell 19mm SWA at 1085x. Both are 2".
Before going to the eyepiece I used the telescopes guider CCD camera to center the telescope on the field. Attached is a raw fits
image of the field 3.7 minutes of arc square. This is a 1" exposure. GJJC1 is plainly visible as is star V8.
I then went to the eyepiece. First I used the Modified Plods and the finder charts from your web site. The seeing was variable, but
with periods that were very steady. The field was easy to identify thanks to the charts from your web site. I did not have any filters
with me. While I believed I could identify JOCK I decided to switch to the higher power lemma eyepiece. This brought out even
fainter background stars which confirmed my identification of GJJC1.
The time and date of the observation was 01:30 MST on June 11, 2005. The sky was clear. The temp 57 degrees at 40% humidity.
This observation was made much easier then it could have been by the fact that I was able to identify and center the field using the
CCD before going visual. Also there is something to be said for aperture!
Eric Honeycutt Observation Report on GJJC1
Date: 6/24-25/01
Location: Troutdale, VA
Site Classification: Rural
Elevation: 3600'
Limiting Magnitude: 7.0+
Transparency (1-10 Best to Worst): 3
Sky Darkness (1-10 Best to Worst): 2
Seeing (1-10 Best to Worst): 3
Temperature (F): 57
Wind: SW @ 10mph
Instrument Used: 22" f/4.1 Newtonian Reflector
GJJC1 (aka: PK 9-7.1; PNG 98-7.5): PNe w/in M22 - Sagittarius.
Object Data: Mag: 15.0(P); Diam: 8.5"; CS: 14.3
Description: 02:22 - 376x/501x/864x and UHC/O-III:
Beginning at the advent of darkness, I began analyzing the fine globular M22
with a detailed star chart from Megastar along with some hi-resolution
photographs of the general location GJJC1 w/in M22. After 10 minutes or so, I
quickly found the general location of the PNe.
On the NNE border of the central concentration of the globular, there is a
distinct wedge shaped asterism that points almost directly to the location of
the PNe, which is located in the SW quadrant of the globular. In this sector,
there is now an asterism that takes the shape of a baseball diamond (see photo
below). Directly ENE of the baseball diamond and on the opposite side of the
M22, there are 2 more stars w/ a 30" separation extending along a NE/SW
axis that are of relatively equal magnitude (roughly 12th V) that served as my
field markers. GJJC1 is located a third of the way between 2nd base of the
diamond and the southern most star of the two addressed above.
Pinpointing the specific area at 376x and no filter, I noticed a 13th to 14th
mag star in the +/- 10" general location of the Pne. I knew this star would
practically butt up to the planetary. Reading the few observations that there
are of ths object, I immediately understood what the task before me would
entail: to successfully confirm this PNe, I had to split this small star and the
PNe itself. If successful, the southern most object would be GJJC1!
I immediately switched to 501x and took out my O-III and UHC filters. The
seeing, though not great, was relatively steady every few seconds. Still I could
not discern that there was anything else there but a relatively faint star.
Underneath a velveteen cloth, I began blinking the O-III filter. The field was
rendered very dark - almost too dark for me to keep my bearings in my
non-tracking instrument. Then I switched to the UHC. After quickly blinking the
filter over and over for 20 seconds or so, I began to notice GJJC1 blinking like
a distant beacon every time the filter passed in front of it. It is interesting
to note that once observed, it was actually not that difficult to keep it w/
averted vision - even direct vision every now and again.
Then, I switched to 864x (3mm Radian) w/out a filter and though the stars were
quite soft, I believe that this was the power (and higher if allowed) to really
exploit this planetary. I discerned the object as not disk shaped rather, highly
elongated whereas the stars were still round (well, round blobs). At times I
noticed a very faint stellaring within GJJC1 which is what had to be the CS. It
was not always visible but with my eye at the eyepiece constantly at 864x for
over 45 min's straight, it would definitely come and go w/ the seeing
conditions. The CS was much more difficult than the CS in M57 but seemingly not
as difficult as the CS in Abell 39, for example.
Overall, this was a very tough observation that quite honestly took a lot out of
me. The skies are still very dark with phenomenal structure in the Milky Way
from horizon to horizon and the seeing is pretty darn good for the Appalachian
mountains.
Jay Reynolds Freeman Observation Report On GJJC1
A friend of mine is fond of saying, "If
it was easy, everybody'd do it." She retired at 35 with a self-made
fortune of over a hundred million dollars. When she gives advice, I
listen.
On June 22-23, 2001, I was at Fremont Peak, mostly to look at
Mars. When I got tired of that I decided to look for GJJC 1 and Pease 1,
planetary nebulae associated with M22 and M15 respectively. I seem to have
been successful, and with relatively modest aperture, so I thought people might
be interested in the details.
CIRCUMSTANCES OF OBSERVATIONS:
Equipment: Astro-Physics 10-inch f/14.6 Maksutov-Cassegrain,
with the "small" (23 percent of diameter) central baffle, MaxBright
diagonal, 8 mm Brandon and 6 mm Pentax SMC-ED orthoscopic eyepieces (464x and
618x), Orion "Ultrablock" narrow-band filter, used as described below.
Seeing: Looking at Mars made us much aware of seeing during
the evening. It was episodic, with intervals a few tens of seconds to a
minute long when little Martian surface detail showed, yet there were comparable
intervals of much better conditions. During the latter, the diffraction
pattern of a suitable star at similar elevation to Mars (and to M22 -- M15 was
higher) showed the Airy disc continuously visible but mostly in motion, and the
first diffraction ring continuously visible, always in motion, and mostly
interrupted; that is, I could not see it as a continuous whole. I observed
at 309x (12 mm Brandon) and used the brighter, closer pair of nu Sco for this
test; it was well resolved, with much dark space between the two stars.
Results with the planetaries were in intervals of good seeing; when seeing got
bad, not only the planetaries but also many of the guide stars in the clusters,
that I was using, simply disappeared. Except where explicitly stated, the
notes that follow are based on moments of good seeing.
Sky conditions: Fremont Peak is not dark like the Sierra Nevada, but
transparency was good, and the fog was in on the coastal plain, which much
diminished local city lights. These cities have cut back their nighttime
lighting considerably -- hurrah for the California power crisis! In any
case, sky background brightness was not a factor in these observations,
considering the magnifications used.
Aids to navigation: Some time ago, I downloaded the finder charts and images
that then existed on Doug Snyder's web site, the home page of which is http://www.blackskies.org.
I checked that site while preparing this posting. Doug now has lots more
stuff. I have no way to prepare and append graphics to this missive, so I
will describe star-hopping and so on with reference to Doug's current images.
GJJC 1:
I started with GJJC 1 because M15 hadn't cleared the tree line. Doug has five
images with increasing amounts of detail. The one with the bar 60
arc-seconds long is most useful for describing star-hopping. I found star
"FC1" easily, as the west point of a right isosceles triangle whose
other stars, about as bright as FC1, lie about 40" east and 60"
northeast of FC1. These stars were easy with direct vision.
Centered about 60" toward position angle 100 degrees from the right-angle
star of this triangle, is a star pattern I would describe as a narrow bow tie or
butterfly. It comprises a skewed rectangle, about 10" by 50",
with a star about as bright as FC1 at each corner, with the long axis running
about in position angle 030/210, with a pair of fainter stars at the center.
Star "V8" is about 100" east of the south end of the rectangle.
V8 is one of an obvious quadrilateral of stars, about 30" high and wide.
The other three stars (actually more) are a single star about 30" toward
position angle 160 from V8, a tight group
about 20" toward position angle 250 from V8, and another tight group about
30" toward position angle 225 from V8. All stars mentioned so far
were easy with direct vision at 464x with no filter, and I could tell that the
two tight groups were not single stars. The quadrilateral was very useful,
for it established both scale and orientation at the eyepiece, and GJJC 1 is
less than an arc-minute away.
Look now at the "tilted" image on Doug's pages, from a 1989 issue of _Astrophysical_Journal_.
The star whose disc is cut in two at the bottom corner of that image, is the
southeast star of the quadrilateral just mentioned. Stretching about
25" toward position angle 50 from it, and including it, is a long, narrow
kite or diamond shape of stars, whose long axis is in position angle 050/230.
GJJC 1 is about 20" north of the northeast end of the diamond, and is the
southernmost of a pair of "stars" (actually, both have companions)
that lie some 10" apart on a north-south line. Another easily
identified star in this area was about 30" toward 030 from GJJC 1; on the
"tilted" image it appears as a bright star flanked by three fainter
ones 120 degrees apart. I could see it with direct vision, and could tell
it was not merely a single star.
The "cut-in-two-at-the-corner" star was easy with
direct vision at 464x. The other three stars of the diamond were more
difficult with direct vision, but easy with averted vision. There was no
sign of GJJC 1 with direct vision, or of the star 10" north of it, but with
averted vision, I occasionally saw stars at the correct positions for this pair
-- sometimes one, sometimes two equally bright. The proportion of time at
the eyepiece during which I could see stars at or near the position of GJJC 1
was no more than a few percent, but that proportion includes times of poor
seeing; in good seeing I believe I would have seen the averted-vision stars in a
much higher proportion of the time. In any case, with patience, the
averted-vision observation was repeatable.
The two "stars" at or near GJJC 1's position were so hard to see that
there was no hope of "blinking" the usual way, by interposing a filter
between eyepiece and eye, so I took the star diagonal off the back of the
telescope, attached my Orion Ultrablock to it, and put it back. Here I
must give due credit to Scott Losmandy -- I use a G-11, which many consider too
little mount for 40 pounds of OTA and fittings plus two 21-pound counterweights,
but after all the fumbling with the
filter, when I looked through the eyepiece again, the line of sight was within a
few tens of arc seconds of where it had been before. Stellar images were
much dimmer, but the stars of the quadrilateral were still detectable, so there
was no issue of not knowing where to look.
In this configuration, during several minutes of observation,
I several times saw a single star by averted vision at the position of GJJC 1 --
never two stars, always just one. The averted vision image was noticeably
brighter, compared to the "blinked out" stellar images nearby, than
had been the averted-vision images that I had seen without the Ultrablock in the
optical path; that is, the image that I was seeing clearly had not had its
brightness as much diminished by the filter as the other stars. (If it
had, I probably would not have seen it at all.)
All averted-vision images appeared entirely stellar, at least in good seeing.
There was no trace of anything I would call "nebulosity".
The processed image on Doug's pages, with continuum removed, shows that GJJC 1
has a small, nearly stellar component that is quite bright in OIII. I
believe that is what I saw. I think this is a reasonably convincing
observation of GJJC 1, though it wasn't as much fun as if I could have pointed
at something and said "Wow, there it is!" Instead, I had to make
lengthy observations with two different configurations of the telescope, and
then think carefully about what I had seen.
CONCLUDING COMMENTS:
I mentioned what I was doing to a couple of people present,
but no one was much interested in looking at the planetaries. Most of the
local crew aren't as craz- er, enthusiastic, about deep-sky work as I am.
Anyhow, it would be difficult to show these targets to a line of people.
Each observer would have to spend much time comparing finder images to the
eyepiece view, to determine where to look, and would then have to wait for good
enough seeing to see the objects.
Without the excellent finder images on Doug's web site, I
wouldn't have had a ghost of a chance at finding either Pease 1 or GJJC 1.
Furthermore, I cannot overemphasize the importance of good seeing in finding
them -- without conditions that made stellar images small enough to see the Airy
disc, I am sure that the star-like core of GJJC 1 would have been smeared out
and undetectable, even with averted vision, and that the brighter and broader
glow of Pease 1 would have merged in with the fuzzy images of nearby stars.
I am sure that a lot of credit also goes to the high quality, excellent
polish, and freedom from scattering of Astro-Physics's optics -- you can't see
the corrector plate on the AP-10 even when you are shining a light on it, the
secondary spot just seems to hang there in space.
I hope my remarks are encouraging and helpful to others who
may try to view these faint planetary nebulae. It is probably true, that
if it were easy, everybody would do it. Yet just because it's not easy
doesn't mean it's not possible. - JAY REYNOLDS FREEMAN.
Kent Wallace's Observation Report On GJJC1
GJJC1 = PN G 009.8-07.5
18,36.4 -23,55
MAG ? SIZE 9" on 8/20/00. In the 7mm Nagler (363X) could see a faint
pair of stars arranged north-south with adverted vision alone. This pair
is just where Doug Snyder's finderchart shows them to be with the southern
component being GJJC1 but could not get a response to the filters at this power.
In the 4.8mm Nagler (529X) the PN looks a bit fatter than its partner when using
averted vision. Got a fair and unsteady but real response to the UHC
filter and a poor and unsteady response to the O-III filter. Got no
response to the H-B filter. There is now way I could have found this PN
without Doug's finderchart.
Kent Wallace, Navaho Flats, California, 20" f/5 reflector.
Jay McNeil's Observation Report On GJJC1!
| Preface to the report: My congratulations
to Jay for this excellent observation and for contributing it to this web site for the opportunity to share it with observers all over the world! I hope that it inspires others to attempt to view this most challenging object, as it does me! Doug Snyder. |
...I must add that I have seen this
object once. After literally eating, sleeping, and breathing PNe for about 6 months to
prepare Megastar's database, I arrived at TSP ' 96 with a new 16" and a suitcase full
of charts for "never before seen" PNe. One of these happened to be GJJC 1
located in M 22. Of course, I had long before seen Ps 1 in M 15,
but I really got some strange looks when I threw this chart on the table amongst some
fairly experienced observers. I had cross-referenced the coordinates and other data as
much as possible for accuracy, and my position was as good as one could get (or at least I
thought so). I played around with the field with my 16" in "not so good"
seeing the first couple of nights to no avail. Then, on a night when the seeing was truly
steady, I tried again with the 16. After about an hour and a half of fumbling around
inside the core of this monster globular at 427x, I came to the realization that I needed
more aperture in order to better resolve the inner most stars where the nebula lies. Onto
the scene steps a good friend of mine, David Tosteson--aka-"Minnesota Dave" and
his 25" f/ 5 Dob. He and I quickly had the cluster's core at 661x, and the core stars
separated completely and fit my chart wonderfully. Since I already knew that the PN's
emission characteristics were very odd to say the least, we sampled a number of filters,
but most had too narrow of a bandpass for this power and added too much contrast for the
field stars. When the field was blinked, however, with a Lumicon UHC filter, a faint
non-stellar (well, of course EVERYTHING is non-stellar at this point) object popped into
view at the exact position of my charting. The object was just advertedly visible without
the filter, but definitely reacted to the UHC. I would assume it would react likewise to
the Orion Ultrablock, which has a similar bandpass. And, hey, all of this was being done
while everyone else was screaming across the field about how good some
"planet"looked through their giant scope!
More power seemed useless on this particular night with the 25", and much less power
was definitely useless in the observation. I've tried repeating the observation a couple
of times with various scopes (including a buddy's awesome 36" f/ 5) to no avail. I've
actually become quite good at acquiring the field of the PN, since the object resides just
inside the NE corner of a small (27" high by 23" wide) inverted pentagon
composed of 5 mag 13.0-13.6 stars. I call the structure the "house" when
describing the area to others when at the scope. Ironically, the very next day at TSP, I
had the entire field etched into my memory as I went digging for high-resolution pictures
of M 22, and guess what I found??? On page 195 of John Vicker's Northern CCD Atlas Vol. 1,
there's a rather serious image of the innermost 3.6' by 4.35' of the core of M 22. With a
good magnifier, our tricky little PN is plainly visible!!! You ought to check it out.
Doug Snyder's Report on his observation of GJJC1
Touring around Virgo on Thursday, May 4, I noticed around 1 AM that both the seeing and transparency had improved considerably. I decided to try another personal quest, which was seeing the planetary nebulae GJJC1 in the globular cluster M22 in Sagittarius.
On my PN web site, I
have a series of finder charts, information, and one positive observation report
(Jay McNeil's) on this PN. I had not previously even attempted this one,
as not having a telescope with enough aperture kept me away from anything this
challenging (But now with the 20", I'll try
anything!). A challenge it is, and does make the list on Jim Shield's
site.
Since M22 would not transit until around 4 AM, I decided to follow its journey up, and dig into the necessary star fields as it approached its
highest point of 34.7 degrees above the southern horizon here in Palominas, Arizona (latitude of 31 degrees). Using the finder chart printed out from
my web page and Jay's notes, I soon found myself (well, within half an
hour!) in the region of where the PN resides (the PN is about 8" in size
and about mag 15). Over the next hour, I went from 149X to 605X using various
eyepieces and filters (both O-III and UHC). I was also trying out two different Barlows, one a 2X from
a well known popular telescope maker, and a 2.5X Televue. With the same eyepiece (10.5mm), I found the Televue to deliver a considerably
sharper image in spite of the higher magnification. At about 2:40 AM, I got my first confirmation
of the PN with the O-III after suspecting it initially without a filter, and that was
difficult enough, having to use averted vision in both cases. I also blinked with the UHC, and maybe saw a slightly better response than with the O-III,
but its hard to say. Taking a break from the eyepiece, while still
maintaining night vision, I returned to go over the entire sequence again about 40 minutes later when M22 had reached an altitude of about 34 degrees,
about a half hour before transiting. Like Jay says in
his report, the field stars and their positions seem to get etched into your memory, and it did
not take nearly as long to zero in on the coordinates of the PN. I don't
know if it was because of the higher position in the sky of M22 or the sky conditions had improved more, or a combination, but at 605X, I was able to
directly view the PN for about 50% of the time as a very faint (almost) stellar object. This time I blinked first with the UHC and then with the
O-III. I definitely could see a more positive response with the UHC, but
still could confirm the PN with the O-III. Everything else in the field either became unobservable or a dark gray smudge. The fun part of this at
605X was doing the blinking, moving the scope (not motorized), and making sure the focus was continually precise. I'd like to see positive
or negative reports on this PN with scopes in the 13" to 18" range - I
think its doable under the right sky conditions, and from mid latitude locations,
but of course the more southerly one is, the better the chances. It'll be
a pleasure for me to be able to put in my own observing report of GJJC1 next to Jay's, and move on to the next PN challenge - in my case, I'll wait for
Pease 1 in M15. For those really wanting the ultimate PN challenge
(besides GJJC1), there is JaFu1, confirmed to be a outlying member of Pal 6 in
Ophiuchus. So there is a challenge within a challenge! Information
and charts on both JaFu1 and JaFu2 (in NGC 6441) can be found on my site at http://www.blackskies.org/JaFu_challenge.htm
.
Observing Report Received From Barbara Wilson (via amastro):
From: Barbara Wilson
Date: Tue Sep 14, 1999 0:49am
Subject: Re: PK 009-07.1 (IRAS 18333-2357) in M22
What a night of observing Larry Mitchell and I had last Saturday Night at the
Columbus Observing Site west of Houston. The seeing allowed powers of up to 950x
and the transparency was excellent in the hours up to 1:00 am.
That the night was going to be exceptional was apparent from nightfall, with
Mars steady as a rock. Larry immediately went to M22 in Sagittarius, to attempt
PK 009-07.1 (IRAS 18333-2357) in M22, a "holy grail" of deep sky
observers.
At 808X in Larry's 36" driven Obsession using charts he obtained from Brent
Archinal, and special charts Larry made over the past several weeks, (using a
edit version of MegaStar to add appropriate stars to the M22 charts using a Real
Sky Overlay), Larry spent much time carefully starhopping across the cluster,
then saw the planetary. But it would not "blink" with the O3 filter.
My turn, using his wider field chart, then the IRAS zoomed in chart, it took me
about 15 minutes, to rectify the starfield with the wide, then the zoom chart,
even with Larry's careful guidance.
I noticed that the nearest star to the planetary would harden, as Brian would
call a "stellaring" but the planetary never did. It remained nebulous.
Wow. I mentioned this to Larry, then he went back up the ladder, and also
noticed the same phenomena. Again the stars would harden, but the planetary
never did, and Larry noted that he might have seen a disk.
I then with the starfield memorized, went to my 20" using a 6 mm Radian
eyepiece and a 2.8 Klee barlow, effective power of 950x with tracking platform
working perfectly, also observed the planetary, with Larry confirming the
observation.
My congratulations to my friend, and observing buddy, Larry Mitchell for the
observation of this "ultimate challenge"!! And I can confirm it is
visible in a 20" using "obnoxious powers". The sub arc second
seeing was what I believe made the real difference. I made a drawing at the
eyepiece of the starfield at 950X with the planetary. The nearest star to the
planetary is very similar in magnitude to the planetary itself.
--
Barbara Wilson