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CN Report: Where is M13?


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where is m13
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...

Where is M13?
http://www.thinkastronomy.com
$19 USD
Mac, Linux or PC
Requires JAVA runtimes


(BTW - Guys?  I think we may be in trouble when our female membership reads this... Ladies? )





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