Sunday, July 05, 2015
Finding Pluto...
I’m conflicted about Pluto. Oh, not Pluto the Disney dog. I love that Pluto just like I love (almost) every other Disney
character. No, I am talking that pesky little dwarf planet. The former ninth
member of Sol's family and I have a rather complicated relationship.
That relationship began when I was a youngster, a
proto-amateur astronomer. Like the rest of my generation, I learned all about
The Sun’s Family of Nine Worlds early in elementary school to include memorizing the
names all of 'em. Kinda tough for the little folk, but required in the space crazy
days of the nineteen sixties. Luckily, there was a mnemonic many of us
still cherish: My Very Educated Mother Just Showed Us Nine Planets.
When I stopped being a proto-amateur and became a real one,
I naturally wanted to see all of The Nine. I only got eight; Uranus and
Neptune were more than challenging enough for my little telescope. I wanted to see Clyde Tombaugh’s and
Percival Lowell’s world, but I set that aside for “someday.” Not only will it
not show a disk and is, therefore, only identifiable by means of comparing the star
patterns in an eyepiece to those of a detailed finder chart, it has a
somewhat punishing visual magnitude that
usually hovers around 14 (it can vary from about 13.5 to all the way down to
16).
That was way too dim for my 4-inch Palomar Junior and still
too dim even when I moved up to a 6-inch home-brew Newtonian. To corral Pluto, you need at least an 8-inch telescope,
and as a young teen I couldn’t dream of owning such a huge instrument. Hell,
the Edmund Scientific 8-inch Newt was well over 400 dollars with shipping. This
in the days when your old man might bring
home 200 a week if your family was firmly entrenched in the middle class.
So, Pluto had to wait for well over a decade, till I glommed onto
my first Celestron C8 Orange Tube SCT. Actually, it took me quite a while after I got that scope to
get around to chasing Pluto. What finally impelled me to do so was the prospect
of moving back to Mobile, Alabama. I knew the dark skies of the Ozarks in
Arkansas where I was living would make the hunt far easier than the soupy,
humid skies of home.
An 8-inch is big enough for Pluto, but you know what? It is
just barely big enough. At magnitude
14 and change, which he was at when I went after him, and which he is at now (14.1
to be precise), he’s in range of an 8-inch with clean optics and dark skies.
But easy? No. At about 300x I thought
I saw a pinprick in the correct position using Sky & Telescope’s yearly finder chart. I even imagined the
speck had moved when I came back a week later. Maybe.
Not to be a party pooper, but, frankly, Pluto was probably even a
little easier then than now. He was located away from the summer Milky Way
where he is positioned at this time. There were fewer “comparison” stars to use
when checking for movement, but there were also far fewer field stars to
masquerade as that silly little dwarf than there are today with him over in
freaking Sagittarius.
Well, every party needs a pooper and that’s why they invited
me. Let me take that a step further. If you want Pluto to be reasonably easy,
especially under less than perfect skies, you want to look for him with a
16-inch. Which was my takeaway from the
1999 Texas Star Party.
That May, Pluto was actually slightly brighter than he is this
month, being at 13.73. Which didn’t sound too bad. I’d have my 12-inch Dob, Old
Betsy, and I’d have the pristine skies of Prude Ranch. I put Pluto on my observing
list. “Easy-peazy,” I thought. Hah.
When I got the scope pointed at the proper area of
Ophiuchus, I began studying the field in the 12mm Nagler, which, in concert
with the 2x TeleVue Big Barlow, which was my big buy at the ’99 TSP, delivered
250x, a pretty good Pluto power. I looked in the eyepiece, and I looked back at
the very detailed chart I’d printed with Megastar (software). Nothing hopped
out at me that might be the last stop on the way to the Kuiper Belt. I looked
some more. After about 15-minutes I spied the minutest, most fraking
insignificant speck that appeared to be in the correct position. No, magnitude 13.73
theoretically isn’t that dim in a 12-inch
under good skies and with medium-high magnification, but it sure looks dim when
it’s just a “small” star in a crowded field.
I will say that when I came back a couple of days later to
verify Pluto had moved (via the quick field sketch I’d made the first night),
it was somewhat easier to find and see him. But easy in a 12 even under the
near perfect skies we had that year? N-O. Not for me, and I suspect not for
you. Yes, people say they’ve seen him in a 5-inch, but I am dubious. That would
take perfect eyesight, pupils dilated to the max, perfectly dark skies, and
very steady seeing—any wavering will make the pinprick that is Pluto
disappear.
What with the New Horizons spacecraft approaching Clyde’s Rock, the
hunt will be especially fun this July and might be a way for energizing your club during the summer
doldrums. Taking a cue from SkyTools author
Greg Crinklaw, who suggested to the SkyTools
Yahoogroup that chasing Pluto would be an interesting endeavor with NASA’s
probe only weeks away, I’ve challenged everybody in my club who owns a 10-inch
or larger telescope to try for the dwarf planet from our dark site.
When the spacecraft reveals the weird and wonderful (as it
no doubt will) when it comes closest to Pluto and his satellites on July 14th,
it will be extra special for those of us who are in the very tiny minority of
humans who’ve laid eyes on the world with their own eyes. No, he’s not very far
away when compared to the distant galaxies many of us observe, but he is small
and is out there on the edge of the Solar System and it is an undeniable thrill to say you
have tracked him down.
What will I use for my Pluto quest? I’m going for the gold,
y’all. I will initially attempt the observation with my 10-inch Dobsonian
(Zelda). Since I’ve seen Pluto before and know what to expect, I think I can do it if the skies
cooperate. The main impediment, I believe—assuming we get some relief from near-constant
clouds and rain—will be the terrific haze. If I miss, I’ll kick it up to my 12-inch (Old
Betsy). If still no PL do I see, I will get a buddy with a larger scope to put
Pluto in the field. Ain’t too proud to beg. Seeing Pluto in concert with New
Horizons' arrival is a once in a lifetime opportunity.
Any tips I can give novice Plutophiles running down the rascal for the first time? Other than "pour on the aperture," use plenty of magnification. Especially if your skies ain’t perfect. 200x to 300x is a good power once you
have (you think) Pluto centered. And don’t be hasty. Don’t just take a 2-minute
look in the eyepiece and decide “noseeum.” Spend a half hour minimum before throwing in the crying
towel.
How can you be sure you have seen Pluto? The time-honored
method was to draw the field and come back in a few days as I did at TSP. Even
then, however, that really wasn’t necessary any longer. A highly detailed chart for your date, time, and location produced with a
computer, showing stars down to the limit of your scope, will probably allow you
to pick out Pluto without doubt. In those days I used Megastar.
Today it is SkyTools 3 or a new
favorite, a freeware planetarium, C2A.
Don’t have nuttin’ but an 8-inch or smaller scope? If you
have a camera of some kind, a DSLR or a CCD or a deep space video camera, imaging
Pluto is like shooting fish in a barrel if your goto is accurate enough to put
the dwarf in the frame of your sensor. If I fail visually, I might break out the
Mallincam Xtreme and the Edge 800 (Mrs. Emma Peel). For a rig that can bring
back 17th magnitude galaxies, Pluto ain’t nothin’ (not a thing).
What else is there to say about Pluto? There is that elephant
in the living room. He is the world who got demoted. Who the IAU reduced in
status from major planet to dwarf. A lot of folks got upset about that. Not just
amateur astronomers, who tend to become emotionally invested in such things,
but even the general public. Some couldn’t find enough bad words to aim at Neil Tyson, who came out strongly in favor of ending The Nine some years
ago.
Why all the hubbub, Bub? I often wondered about that. So I
decided to find out. Who better to ask than the students in my university
astronomy labs? PH101 is to some extent a “service course,” drawing students
from majors ranging from math and physics to art and P.E. and that seemed the perfect group to ask. I don’t know a thing
about doing surveys, so I just asked the kids a few (written) questions. "Have
you heard the International Astronomical Union no longer classifies Pluto as a
(major) planet? Do you agree with that decision? Why or why not?"
Reading the answers my students gave made one thing
clear: even among the most
scientifically literate, science had little to do with Pluto. It was
all about emotion. When I boiled it all down, there were two reasons students felt
sad for the hellish little world. First, like me, they had fond memories of
learning The Nine in elementary school. Secondly, they seemed to at least
subconsciously conflate this lonely little world with Disney’s friendly cartoon dog. That last
seems strange, but I tend to do it too. When someone says “Pluto,” the first
image that pops into my mind is not some godforsaken rock, but Mickey’s
faithful hound.
What do I think? As
an astronomy educator at a university, I straddle the worlds of professional
and amateur astronomy, but I have to come down with most professionals on this
one. Considering Pluto the same sort of world as the major planets is just silly.
To begin with, he is tiny, 1471
miles in diameter, which is smaller than Earth’s Moon. Why was he ever considered a major planet? Initially, it was thought Pluto was somewhat larger than Earth. Maybe as much as twice the size of our home world. Over the
years, he’s been continuously downsized. Every time we’ve learned more about
Pluto, he’s gotten smaller.
Secondly, Pluto’s orbit is fairly highly inclined to the
ecliptic. He is well out of the plane shared, more or less, by the eight big
guys. What does his orbit (which crosses Neptune’s path) look like? It looks like the orbit of a comet or
asteroid.
Then there’s the company he keeps. If there were only one
world like Pluto out at the edge, I suppose a better case could be for keeping
him in the family, but that is not the way it is. There are plenty more where he
came from like Sedna (who may be slightly larger than Pluto). Eris and Makemake
are pretty clearly bigger than poor PL. There are no doubt thousands of Kuiper
Belt Objects, including some that are indeed larger than Pluto. Should the kids
have to memorize The Nine Hundred?
What is there in Pluto’s favor? Several cases for retaining
him have been made. For example, Pluto has moons. Just like a major planet. But
some asteroids have Moons, too. Frankly, most pro-Pluto arguments are, just
like my students’ responses, based on emotion. The ground truth is that Pluto
is just different from the Sun’s eight major planets.
Frankly, I’m weary of the Pluto dust-up. I’d be OK with it
if the IAU decided to grandfather him back into major-planet-hood. But even if
they don’t, who cares? If you want Pluto to be a planet, he’s a planet.
Who cares what a (poorly attended) IAU session came up with? Frankly, they
fumbled the ball so badly on Pluto, especially PR-wise, that I wouldn’t be
surprised if they revisit the issue someday.
Anyhow, whatever you think (outraged comments from Pluto's supporters will not sway my opinion, by the way), get out and enjoy Pluto this month, whatever he is. Even if
you don’t spot him in your very own telescope, the search will be fun.
If you do make out that desolate little pinprick, why all the sweeter...
Comments:
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Nice one Rod. Was really fun to read. One thing hit home, and that is, that we are able to look at a tiny rock, about 1471 miles in diameter, that only reflects light with an amateur class instrument.
In all my decades of visual agronomy, I've never passed the GOTO button to Pluto. Now I think the time is right.
# posted by 
: 11:15 AM
: 11:15 AM
Seeing Pluto with your scope this month maybe the only view we get now that New Horizons has entered safe mode for 10 days so no science can be done as it approaches. I hope it comes back on line as there seems to be some weird features that beg for a closeup. The free app Pluto Safari has been great, if you don't have it, check it out. I have not seen Pluto with a scope nor bothered to search for it and now it is very low from my lat. I may be one of the ones using astrovideo to catch it. Thanks for the timely read Rod....Dwight
As usual, the lay media is behind the power-curve. Communications has been restored and the spacecraft is healthy.
:)
:)
At this time, it LOOKS like everything is going to be OK... http://www.skyandtelescope.com/astronomy-news/new-horizons-safe-mode-07052015/
I got him myself a couple years ago with my CPC1100 at a star party at a nice dark site. Tracked him over three nights. My final planet, for the AstroLeague Solar System certificate. I think I also tracked Ceres and Vesta at the same star party. Quite exciting, really, even though Pluto was just at the limits of my CPC1100 at that time and so was just barely visible.
# posted by : 6:15 PM
: 6:15 PM
Well, the latest image of Pluto taken by New Horizons on July 8 is revealing increasing beige weirdness. It's fascinating to contemplate that we are seeing Pluto with such clarity for the first time in the history of man. Inspired by Unc's example, I think that I'll fire up my CPC 925 and try to catch a glimpse of the little booger this weekend.
# posted by : 10:34 PM
: 10:34 PM
Wow, you have my deep respect as always! I had the pleasure of being at the Sonoma County Astronomy Society's club observatory site up at about 2500' above the Geysers in the Myacamas mountains with a my newly-finished 10" Dob and a friend while Morris Jones and Jane Houston Jones were working on capturing Pluto with their 17" Dob. When they excitedly found it, they were kind enough to invite us to look through their eyepiece and see it ourselves.
Now, I've never had much luck in seeing sharp or dim objects in any telescope and was frustrated by what appeared to be a black field with the faintest hints of illumination here and there. But I know those two well enough to be sure that they were "confirmed Plutocrats".
It is a delight to read of your observations! And I'll continue to enjoy such faint fuzzies as the Ring, the Whirlpool (when I find it) and other simple objects. Simple, perhaps, but far more than what I'd see without the telescope - or your inspiration.
Best to you always from the Columbia Gorge!
Now, I've never had much luck in seeing sharp or dim objects in any telescope and was frustrated by what appeared to be a black field with the faintest hints of illumination here and there. But I know those two well enough to be sure that they were "confirmed Plutocrats".
It is a delight to read of your observations! And I'll continue to enjoy such faint fuzzies as the Ring, the Whirlpool (when I find it) and other simple objects. Simple, perhaps, but far more than what I'd see without the telescope - or your inspiration.
Best to you always from the Columbia Gorge!
Nice article Uncle Rod. I enjoyed it from the beggining to the end. Still waiting the day (I must say the night) that I could see Pluto with my own eyes.
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