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Where is M13?
(Version 1.6)
Tom Trusock
8/06
Where
is M13?
Positional Software Package
Mac, Win, Linux
$19 USD
Guys
work on vectors.
We’re never lost.
That’s Guy Rule #45384. You Are
Never Lost. The guy in front of you might be. (So
what if you’re following him? You know where you are.)
Maps are cool, but completely unnecessary. Well, unless you’re
backpacking in an area that neither you nor your brothers, father,
grandfather, second cousin Fred, friend Bill, Bill's friend Bobby, or
your third cousin on your wife’s side – what was his
name? That’s ok, he’s an idiot anyway… Where was I?
Oh yeah, unless we’re somewhere that hasn’t been trod by man (and
lacking game trails) we don’t need no maps. Well, except for
maybe those cool GPS thingies… But we really don’t NEED
those. They’re just cool. Yeah.
How many times have you stopped at a rest area and glanced casually at
that big yellow sticky pin on the map they have hanging up? You
know, the one that says – “You Are Here”. If you’re like
me, you’re careful not to let your wife see you. Hey, but it’s
ok, really. It’s not like it’s a direct violation of Guy Rule
#45384 –
you know where you’re at, you’re just checking to see if they got the
maps right.
Ok, now that we’ve got that bit outta the way, head over to the office
door and close it.
You’re back? Good.
Time to lay our cards on the table. I’ll confess – there are
times I don’t have the first clue where I am. But don’t tell my
wife. Heck, sometimes I even get lost in space - astronomically
speaking. Oh, I usually know where I am in a 2D kinda way, but I
don’t have a clue as to where Col 399 really stands in relationship to
myself and other objects of interest. Heck as far as I’m
concerned, the sky might as well be the big ole' bowl of night with
stars and whatnot just painted on. Oh, I know the Intergalactic
Tramp (NGC 2419) is one of the most distant globulars in the Milky Way
and that it is – uhhhh, lemme see - thataway, but in terms of having a
mental picture in my head of where in space it is with respect to other
targets – uhh uhh.
Remember those Milky Way posters with the “You Are Here” tags?
Truly cool, and I’ll confess I often wondered, just where, exactly
those interesting bits and doo dads lay.
I’d bet most of you are the same way too. It’s ok.
Remember, we’re all in this together.
Bill Tschumy (Think Astronomy) has evidently wondered the same thing,
and he’s here to help.
Bill is the author of “Where is M13?”
a program designed to put things in perspective in a big way. Or
should that be put big things into perspective? Anyway, “Where is M13” is a truly unique
program. It's the first 3D sky chart,
complete with a “You Are Here” viewing pane.
When you start the program, you’re greeted with a two panel
graphic. One shows a face on artist's rendering of the Milky Way
(based on Spitzer data) while the other panel shows a side
view. On each panel, the first thing you’ll note is an orange dot
sitting all by its lonesome, embedded in one of the arms.
That’s you.
In the text panel below the images, you’re presented with a list of
deep sky
objects. Select one – say M13 for example - and now another
orange dot appears on the map. A little inspection shows that
it’s down arm from us and located above the same galactic arm we’re in
– Orion / Cygnus.
That’s M13.
Pretty cool, eh?
Now step back and relax for a minute – y’all don’t want to get too
worked up. It’s a big thing finding out you don’t live in
flatland. Yessir, we’re now getting our reference points.
Head out to the fridge for a minute – grab something to drink.
You've earned it.
Ya back?
Ok.
Let's give you a dose of the familiar. Click on the tab that says
“Sky View”. This look a little more like you’re used to?
Yeah, me too. Notice that there’s only one yellow / orange dot
here. Since this is our typical perspective, that’s M13.
Though similar, this map’s a bit different from a standard
skymap. Everything
is plotted in galactic coordinates. The red lines show the
galactic plane and axis.
Pretty cool, eh?
I found switching back and forth between the two views helped give me
an even better idea of where I’m looking. Both views allow you to
zoom in and zoom out. There’s even an autozoom feature to give you what
Bill feels is the best viewpoint.
You can toggle the data shown. The default view gives you
Galactic Latitude and Longitude, luminosity (in number of suns) and
size (in light years). Checking Show
Apparent Data yields
information most of us are probably more familiar with – RA, Dec, Mag,
and Size (in arc min). You can sort this data by any of the
fields listed – very handy for figuring out what you’d like
displayed. A check box labeled Show allows you to display the
object on the Galaxy and Sky views, and highlighting an object circles
it on the maps. Conversely, selecting an object on the maps
highlights its data.
A handy filter box allows you to quickly narrow down what you'd like
displayed.
I just sat and played with this program for hours. Globular
Clusters are a favorite of mine, and it was fun to see how they are
arrayed around the galactic disk. We know NGC2419 as the
Intergalactic Wanderer, and that was one of the first things I checked
out. The program lists it as having the luminosity of 425,000
suns and a distance of 275,000 light years. “Where is
M13?” also gave me a nice visualization that helped me solidify
my
understanding why the Terezan globulars aren’t more popular.
Check out the plotted Planetary Nebulae.
It was interesting to see the distribution of various classes of
objects. Sure, you know about that big bulge of gas and dust, and
you know it affects our view of the universe, but it’s really neat
seeing it driven home graphically and helps you “get it” at a deeper
level.
I had several personal epiphanies while using “Where is M13?”…
So, what’s there anyway?
91 Planetary Nebulae
151 Globular Clusters
286 Open Clusters
75 Diffuse Nebulae
136 Galaxies
100 Stars
With a total catalog of 839 objects there’s plenty to look at.
Sure, in these days of 15 bajillion trillion sized stellar and object
catalogs, that may not SEEM like a lot, but nearly everything I went
looking for was there, even some of the odd stuff; Djorgovski 1
for instance. I’m sure Bill would love to add more objects, and I
suspect he will down the road – the problem is obtaining accurate
distances – and that’s the crux of this program.
There's also the option to turn on other positional aids - like the
labels for the arms, and the Milky Way constellation sectors.
There are a few notable absences. The Messier catalog only lists
108 entries. Missing is the double star M40, and the
controversial M102 - although the proposed candidate (NGC5866) is
present. I’m puzzled as to why M40 is absent. Its distance
is listed at 510 ly in some of the online catalogs, but perhaps this
figure isn’t as exact as the rest of the data in “Where is M13?” or,
perhaps the author gives credence to the theory that M40 is an optical
double, and thus any distance for the pair is suspect.
This brings me to one conspicuous absence in the program – there’s no
data on double stars. I’m not a huge multiple star observer, but
it would be nice to see the inclusion of a few of the more popular ones.
And while I’m griping (a hobby of mine), there are another couple of
other (very minor) issues. By the program's very nature it tends
to do
better with galactic (close) objects. The Milky Way makes a
nice frame of reference to help you get your head around an object's
location. However, when an extragalactic object is selected, the
Milky Way collapses to a dot, and the obvious frame of reference is
lost. Ideally, it would be nice if the program automatically
displayed other, unselected, galaxies in the same cluster for reference
or a small wire frame orientation reminder of the Milky Way in the
corner. A partial workaround is to create a list of galaxies
using the filter and then select the particular galaxy of
interest.
Another very minor grumble - when zoomed in, the galaxy looks a bit pixelated. Since the image was taken from the one created using Spitzer data, I guess we've got NASA to blame for that. Come on here guys - if these are my tax dollars at work, let's see a more hi-res rendering of our galaxy!
Why so few objects? Distance data on many objects is
either lacking as discussed previously or (seemingly)
constantly undergoing revision. Thus, take all the data with a
grain
of salt - it reflects the best info Bill can currently obtain.
So don't blame the programmer if it conflicts with
other values you've heard! Remember, distance estimates are just
that; estimates. And as the credits screen notes –
this program is not intended for navigation purposes...
"Where is M13?" is written in
Java, so it’s easily (and already) ported to Mac, Linux and
Windows platforms – just make sure that you have the latest version of
Java installed on your machine. I did run into a minor
issue getting the program up and running. Simply put, if you’re
running an XP machine make sure that you are using a default windows
theme. Be certain to disable any software that modifies the
appearance like Style XP. Once I got “Where is M13?” running, I
didn’t experience a single crash.
Personally, I would like to see a Palm or Pocket PC version in the
future. While I don’t carry a PC in the field, I wouldn’t be
without my PDA.
I was surprised by the lack of a night vision mode. With an
increasing number of observers using computers at the telescope,
this seems like it would be a natural feature for inclusion in any
astronomical program. It’s not here – but there is an explanation
for that. Bill feels that software solutions don’t do a
sufficient job of preserving dark adaptation and recommends using dark
red Plexiglas or Rubylith. If you want to try a software
solution, he directs you to the freeware Dark Adapted software package and
provides a link on his site.
But don’t let any one of these very very minor issues put you off this
program. Bill Tschumy has created something that belongs on every
astronomer's desktop. This is a great learning tool, and bluntly
put – it’s just plain fun!
Don’t take my word for it. The best thing is to go out
and download a copy yourself. (I know you’ve got a
computer….) A demo version of “Where is M13?” can be obtained from the
Think Astronomy website. The trial version will run for 10 days,
and gives you a perfect chance to see its capabilities. If you like
it, it’s a mere $19 USD to purchase. “Where is M13?” is a small
program (just over 1 meg), both to install and run so system
requirements are fairly light. However, since it's Java based, you may
also need to get the latest version of Java (if it’s not already on
your system). The Java runtimes are free, and Bill has a link to
them from his website. The Java component is a little larger, but
still doable even under a slow dial up connection.
The bottom line; download the trial, close the door, ignore Guy Rule
#45384 and finally find out “Where is M13?” anyway. What’s to
lose?
And if the wife catches you, you can always tell her you're checking to make sure NASA got its data right...
(BTW - Guys? I think we may be in
trouble when our female membership reads this... Ladies?  )
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