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We spent this past week at a meeting about astronomy visualization and how it can be used to show people the wonders of astronomy and astrophysics. It was a cool meeting and I really enjoyed interacting with other folks in the science, research, planetarium, and filmmaking “bizzes.”

So, what’s astronomy visualization (or, as we started calling it, “astroviz”)? Simple. It’s the process of showing images of astronomical processes and events. The images can be from actual data or photographs, or be simulations BASED on actual data or photographs. To give you an idea of the range of astroviz there is, check out this picture recently released by the Space Telescope Science Institute.

It’s a single image of a dying star called V838 Monocerotis. There have been others taken of this same star as it processes through its death throes. In fact, they’ve all been combined into another kind of astroviz “product”, a sort of video animation, as you can see here.

There are many kinds of visualizations, and the ones that hold my current interest are those that I can use in my planetarium shows. For example, Frank Summers at the STScI created a beautiful moving video of the large-scale structure of the universe that is known as the “Cosmic Zoom.”

You can see a small Quicktime of the work HERE.

I’m always on the lookout for cool visualizations like this that can be used in the dome to immerse audiences in the cosmos. So, for me, the meeting was a great way to meet some folks who make astrovizzes and show them how I was using their work. It was also extremely cool to meet other folks in other fields who have an interest in using the same types of vizzes for their work. Very cross-pollinating and at several levels, easily one of the most useful meetings I’ve attended in a while!

Back when I used to lecture in the planetarium I would solicit questions from the audience at the end of each presentation. Every once in a while somebody would ask me what it’s like inside a black hole.

Trick question, right?

Well, probably for some of the more smart-aleck audience members it was. But, I always had an answer. I’d go into a little discussion about how we don’t know exactly, and based on a number of factors (including the laws of physics, some Einsteinian laws, etc.), we’ll probably never have a chance to explore the inside of one (and, if the gravity is so strong that light can’t even escape, is the inside of a black hole REALLY a place we want to be?). Following that there’d be a silence as people digested the idea of “being there”. Then we’d get into a discussion about what it be like to be right next to a black hole, which is a lot easier to describe, even if it IS a shrieking maestrom of radiation and searing temperatures.

At the time I was first in school, back in the dark ages of the early 60s, black holes were sort of a mathematical curiosity, a physics problem for which we didn’t have any good examples. That all changed with the advent of telescopes and detectors able to “see” the effects of black holes, including the jets that spray out from the vicinity of one as matter (stars, gas, dust) spiral into the hole. Moreover, black holes have gravitational effects on nearby stars and gas and dust that we CAN track with spectroscopic observations of the light emanating from the nearby region.

The Milky Ways Black Hole Courtesy European Space Agencys Integral Mission — The Milky Way's Black Hole Courtesy European Space Agency's Integral Mission

Which brings us to the center of our own galaxy, where a supermassive black hole about a million times the mass of our Sun lies hidden by gas and dust clouds and star clusters. This SMBH (for short), also known as Sagittarius A* (or SgrA*), radiates tremendous amounts of energy which we can detect in gamma rays. As luck would have it, we have a spacecraft called INTEGRAL that “sees” that radiation. In the image above, INTEGRAL shows us a gamma-ray view of the region near the center of the Milky Way.

Now, SgrA* is a pretty quiet and harmless black hole, and isn’t quite the powerhouse of radiation that others are—like, say, the black hole at the center of galaxy M87, which sports a very active jet. Yet, in the past, the Milky Way’s resident black hole has been restless, and whenever it acts up, the surrounding clouds light up with the evidence.

Right near SgrA* is a cloud of gas called SgrB2, and the two are about approximately 350 light-years apart. Sgr B2 is being exposed to a blast of gamma rays emitted by Sgr A* that went off about 350 years ago. The cloud absorbed the radiation and has been emitting it. Interestingly enough, the astronomers studying the data think that the whole outburst took at least ten years, possibly longer. And they’re using their studies to figure out how often and how strongly “our” black hole turns on, radiates, and then turns off again.

I have to admit, it’s pretty heady growing up knowing that these weird things that scientists once thought were probably rare are now found all over the place (in many galaxies and at the death scenes of supermassive stars). And, I find it very cool indeed that we can study the near-black-hole environment and learn so much about them.

The Spacewriter's Ramblings

Seeing Astronomy

What’s It Like Inside a Black hole?

Exploring Science and the Cosmos