Death of a star

December 2, 2009

mysteryimageWhat do you see in this image?  Last weekend, readers of this blog theorized about the image to the left, and came up with some beautiful ideas.  An intergalactic butterfly, a space angel, two black holes meeting, looking through the tail of a comet, cosmic mitosis, a speeding galaxy, two stars kissing, star fish kissing, space fish kissing, and a space hourglass were just some of the ideas that also included nebulae, explosions, and (more than once) a mammogram (oh, context is everything, isn’t it, my friends?).

I was overcome by the beauty in your ideas, and the freshness with which you saw this image, which is at once so powerful and yet now almost commonplace in the wealth of detail-rich images that we now routinely get from the Hubble Space Telescope.  Such intricate images are now released regularly … so regularly that they rarely even make the paper.

But really … isn’t it beautiful?

It looks so fragile, so sweet, so … lovely.  You could hang it on your wall. I wonder if it would shock you to hear that this lovely filagree is actually a tremendous explosion of gases from a dying star 3,800 light-years away.  The star, once about five times as big as our Sun, has grown and expanded to many times its size, just as all stars its size and temperature do, until it is as wide as a thousand Suns, all lined up as if they were waiting in line for a once-in-a-lifetime event.  And in fact it is.  The picture you see above is a snapshot of a moment in time during the very death of the star at the center.

The cosmic hourglass you see there is not sheer, but in fact “roiling cauldrons of gas heated to more than 36,000 degrees Fahrenheit….tearing across space at more than 600,000 miles an hour—fast enough to travel from Earth to the Moon in 24 minutes!”  The gases are cast off in layers, taking shapes that tell us about the conditions under which they were shed, and these cast-off gases have begun to glow, basking in the stream of ultraviolet radiation in which the dying star bathes its surroundings, giving them the ultimate in sunburn, next to which our reddened skin would pale.

We can learn a lot from this picture.  The Hubble scientists tell us:

The WFC3 image reveals a complex history of ejections from the star. The star first evolved into a huge red-giant star, with a diameter of about 1,000 times that of our Sun. It then lost its extended outer layers. Some of this gas was cast off from its equator at a relatively slow speed, perhaps as low as 20,000 miles an hour, creating the doughnut-shaped ring. Other gas was ejected perpendicular to the ring at higher speeds, producing the elongated “wings” of the butterfly-shaped structure. Later, as the central star heated up, a much faster stellar wind, a stream of charged particles traveling at more than 2 million miles an hour, plowed through the existing wing-shaped structure, further modifying its shape.

All that, my friends, and much more, from a picture.  An image.  A snapshot that three guys — let’s call them Keith, Howard, and Bruce — took one day with our planet’s most amazing camera, a camera that can see into the far depths of outer space.


Butterfly Nebula

December 1, 2009

That’s right — the image I posted last time really is called the butterfly nebula!  I love that so many of you coined the term as well, and that you had so many great ideas — you all have beautiful minds.

Scientists in Baltimore and around the world took this picture of the butterfly nebula earlier this year with the ever-new Hubble Space Telescope.  The Hubble was launched nineteen years ago by a team of astronauts aboard the space shuttle.  Most people know that that mission was soon followed by the first Hubble Servicing Mission, when astronauts were dispatched to “fix” the giant space mirror.  But did you know that there have been four servicing missions since then?

In May, NASA launched seven astronauts on Servicing Mission 4 (SM-4, on STS-125) to upgrade the instruments on the Hubble Space Telescope.  It’s not that anything untoward had happened to them.  It’s just that their age, and rapidly advancing technology, had caught up to them.  Imagine if you had to use the computer that you used nineteen years ago! The Hubble was the first astronomical observatory (what you and I call a telescope) to be launched with the specific intention of periodic upgrades, fixes, and replacing old technology with brand spankin’ new technology.

The new instruments, the Wide Field Camera 3 and the Cosmic Origins Spectrograph, are more sensitive to light, which means they can take a picture of far-off star formations in a fraction of the time of the old cameras.  Other instruments were brought back on-line and/or upgraded at the same time.  As a result of all this hard work by untold numbers of engineers at Goddard Space Flight Center, astronauts and trainers at Johnson Space Center, launch teams at Kennedy Space Center, and scientists at the Space Telescope Science Institute and around the world, we here on Earth can now see these amazingly beautiful images from galaxies far, far away — and we can see nebulae like the butterfly nebula not just as it would look like to our eyes, but also as it would appear if we had “x-ray eyes” or could see in the infrared.

With instruments measuring the spectrum in so many different ways (wavelengths), scientists can really start to understand what’s happening out there, so many millions and millions of miles away.  We can see pictures of stars being born.  We can see pictures of stars dying.  We can see the myriad ways in which they hang out together and change over time.

Everything changes, you know.  Everything grows.  We just have to know where to look, and to have the patience — and determination — to keep improving our instruments and techniques, and then the curiosity and the wisdom to begin to understand what it all means.

Questions?  I know this isn’t anywhere near my usual topic, but it sure was fun writing about astrophysics and repair missions for a change.  I’ll write about what you can see in the image tomorrow.  What questions do you have?  Ask anything you like … and if I don’t know the answers, I’ll find someone who does!