Washington D.C. with hydrogen sky

Another one for the Americans, but too late for Thanksgiving.

Taj Mahal with Hydrogen Sky

Apparently this is more famous than Cardiff Castle, not sure why.

Unfortunately the Taj Mahal's entrance points due south, so I can't align the hi-res GALFA data properly.

Hydrogen Sky of Cardiff

Yes, another one.

Magellanic Stream over Sydney

It would be impressive enough in the far north of the world, but to see it properly you'd have to go south.

Hydrogen Sky rising over Boston

Looking almost due east, so I can use the hi-res GALFA images for this. There's an annoying white spot that doesn't move for some reason, but since this is the third time I've rendered this I've stopped caring.

I used a similar animation of Prague for my first public talk ("Why the night sky is really boring and how to fix it") on Friday, it seemed to go down well. I plan to do a few more of these for selected international locations.

Hydrogen Sky over the Sphinx Observatory, Switzerland

I know, I know, I keep using snowy images. Next time something different.

Unlike the previous images I didn't even attempt to align the sky properly (field of view, and hence size of the features, is accurate). This is partly because I don't know which way I was facing when I took the photo, and partly because the 0.6 degree resolution of LAB data is just not good enough. The 3.5' resolution of GALFA-HI is much, much better, but that's really only useful looking due east or west. Although I suppose from a high latitude site it would span the whole horizon... hmm....

Magellanic Stream over Prague

From Vitkov hill, looking south. Suddenly realised that there's no need to worry about the vertical field of view of the camera since I'm replacing the sky entirely.

Think I have the calculation finally sussed : the Magellanic Clouds are at declinations ~ -70 degrees. The stream extends more-or-less 90 degrees due north, to declination ~+20 degrees. Since the lowest declination visible from Prague (latitude +50 degrees) is -40 degrees, the stream would span approximately 60 degrees across the sky. Or in other words it would be stupendous.

Star formation explained using balloons

And now, contemporary theories of star formation explained using balloons...

65th birthday celebrations of Jan Palous (our head of group), in which we enact a generally-accepted theory of star formation. Turbulence in the interstellar medium (dry ice) creates filaments (long streams of paper) which eventually fragment into Bonnor-Ebert spheres (scientists wearing hats with hydrodynamic equation for said spheres). These then collapse under gravity to form stars of different masses (different coloured coats) which shine by thermonuclear fusion (flashlights).

Stellar winds eject material (bits of confetti) into the interstellar medium and also disperse the gas (with hair dryers). The massive stars expand (inflate balloons) and eventually explode (burst balloon, camera flash) releasing metals (bits of foil) into the interstellar medium. One of them becomes a black hole (black hat with Kerr metric) another a pulsar (blue hat, spinning with flashlight).

Then the whole thing repeats but the new stars have higher metallicity (shiny masks).

Considering that we practised this a total of two (count 'em TWO) times and the dry ice was only delivered 30 minutes before the start, the various mishaps along the way could have been much worse !

Narrated by me. If you ever had the strange urge to find out what I sound like, now is probably your only chance.

Does this count as visualisation ?

Before I share the star formation interpretative dance video, I'd like to point out that I've already done something much, much more embarrassing.

Hydrogen sky of Prague

I'm giving a public talk in a few weeks (anyone in Prague ? Come along to the astronomical institute !). Haven't really worked out what I'm going to say yet, but who cares, the important thing is that there will be pretty pictures...

The foreground image is a photo I took last year of St Nicholas Church in Old Town Square. The background image is a composite of LAB and GALFA HI survey data. The alignment of the HI data to the photo is only very approximate. For this image it doesn't really make much difference, the basic structures are similar across the whole sky.

(the good news is my earlier picture of the Magellanic Stream over Cardiff is probably accurate after all, FOV issues notwithstanding)

Honestly, for viewing the night sky, optical wavelengths suck.

Visualising velocity vectors

Playing around visualising the velocity vectors of a galaxy simulation...

(obnoxiously large 20mb gif, sorry about that)