NRAO annual highlights, Tripping out to the Lagoon Nebula

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Astro Tidbit

A brief synopsis of some interesting astronomy/science news

Ever since 2019 I’ve had the pleasure of writing and narrating a series of short videos about the National Radio Astronomy Observatory’s year-end wrapup science highlights. Sponsored by the Nation Science Foundation, NRAO is a great organization that manages a bunch of world-class radio telescope, including ALMA, VLBA, and the VLA. These ‘scopes make great scientific discoveries all the time.

That makes the annual highlight video difficult to do; picking just a handful from the array (haha! Ha!) of stories is always tough, and synopsizing them in just a minute or so is far, far harder. But every year, with the help and support of the folks at NRAO, we manage to put these together.

So here’s the video for 2022. It features stars being born by the thousands in the Tarantula Nebula, a 3D view of the orbits of a planet-bearing binary star, an extremely young pulsar (it may only be 14 years old!), and two supermassive black holes that were surprisingly close together in the core of a distant galaxy.

As always, my thanks to my friends at NRAO, and the astronomers who make these wonderful observations.

Pic o’ the Letter

A cool or lovely or mind-bending astronomical image/video with a description so you can grok it

In late summer for northern hemisphere observers, the constellation of Sagittarius can be found somewhat low over the southern horizon. It represents the Archer, but to the modern eye it looks uncannily like a teapot, the glow of the Milky Way coming out of its spout like steam.

The “steam” is the combined light from millions upon millions of stars, so far away they blend into a fuzzy mist. But in that dim fog there is a brighter patch, barely visible to the unaided eye… though it’s dimness should not fool you; at a distance of over 4,000 light years its intrinsic luminosity is fierce. In binoculars it appears as a knot in the fog, obvious and clearly something different.

Through a telescope, the Lagoon Nebula reveals its magnificence. Even in a small ‘scope it appears as a gaseous cloud, and bigger ones show more detail. Through world-class professional grade instruments (see below) its beauty is staggering.

It’s forming stars, nascent suns condensing out of the gas and dust, and indeed buried in the gas there is a cluster called NGC 6530, a nursery containing several thousand young stars, most probably only a million or two years old. The Sun, at 4.6 billion years, is thousands of times older.

Are there stars still forming, even now sculpting planets out of the interstellar material there? To find out, astronomers pointed Hubble Space Telescope into the Lagoon to see if it could find these alien solar systems. The observations, combined with the mighty Very Large Telescope Survey Telescope, manifest themselves as an image of almost supernatural beauty.

I am overwhelmed by this image. Such color and such texture! It almost looks like a piece of cloth or billowing curtain, perhaps even paint seen brushed onto a piece of glass… but in all honestly it most resembles smoke billowing up from a psychedelic fire.

The gas you see is being shaped by numerous forces within it: Hot stars flooding it with ultraviolet light, winds of subatomic particles from those same stars, turbulent motions of the gas as parcels of it slam supersonically into other parcels. It’s a maelstrom.

But order is created out of it. When small overly dense regions form, they can collapse under their own gravity to form stars. The material falls in, and random motions as it does cause the material to form a flattened disk, not unlike the vortex of water as it falls down a drain. The center gets denser, and hotter, and will eventually form a star. The material farther out in the disk can collapse on its own to form giant planets, or small clumps can grow to form smaller planets like Earth.

This flattened clump is called a protoplanetary disk, or proplyd. It’s dense and darker than the surrounding gas, and can appear as a black object silhouetted, shaped like a teardrop or a thick line or even a hamburger, depending on the physical conditions.

It is these proplyds that astronomers are looking for in the Lagoon. Dozens upon dozens have been found in the Orion Nebula, which is closer to Earth (about 1,200 light-years) and easier to study. But that is the only place they’ve been found, which limits our understanding of them. If they can be found in other nebulae, where conditions are different, then far more can be learned about how they form, how they evolve, and how they birth planets.

No paper has been published on these data just yet, but I look forward to reading it when one is. I remember when the first proplyds were found, and have written about them many times. In fact, they play a large role in the chapter in my upcoming book Under Alien Skies, in the chapter about what a nebula would look like if you were inside one. I won’t spoil it here — the book comes out in April — but it would be one of the most spectacular and moving sights in the galaxy.

A planetary system, being born before your eyes…

Until the day we invent faster-then-light travel, though, our view will perforce be somewhat more removed. But, given the power of our telescopes, that is a view I am content with for now.

Et alia

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