Wednesday, July 31, 2013
Every once in a while, I see a new astronomical picture that leaves me with my mouth open, saying "Wow!" The above image, assembled by a talented amateur astronomer, from information taken by a number of different telescopes, is one of those.
This wide-angle view is centered on a cluster of recently-born stars that is known by its catalog number of NGC 2264. Surrounding the adolescent stars is a whole region of cosmic gas and dust -- the raw material from which stars are born. The nearby gas glows with the characteristic red color of its most common constituent -- hydrogen.
At left center is the Cone Nebula, a region of gas and dust in the shape of a sideways dark cone; the energy of bright stars to the right of the cone is eating away at the sides of this thick dusty region, leaving only a cone of thicker material behind.
To the right of the Cone Nebula, you can see an opposite (larger) cone pattern of bright stars stretching rightward. Some people see the lights of a sideways holiday tree in the pattern of bright stars.
At the bottom center of the image, pointing upward into the bluish emptier region (where the energy of freshly made stars is clearing things out), you can see an odd region of gas and dust that is sometimes called "The Fox Fur Nebula." Click on the picture and take a good look -- can you see the head of a furry red fox pointing upward into the bluish region?
The entire complex of stars and gas and dust is about 2,600 lightyears away, which means the light we see tonight left this region about 2,600 years ago -- a time when humans on Earth lived a much more challenging existence and lifespans were less than half of what we enjoy today.
This remarkable picture was assembled by Dr. Robert Gendler, a physician and amateur astronomer, who is a master at working with photographic information using his computer. The image was constructed from information provided by the Subaru Telescope in Japan and the Digitized Sky Survey, put together by astronomers at the Space Telescope Science Institute from a number of earlier surveys of the sky. To see more information about the photo, see:
You can go to Dr. Gendler's home page at that site and then browse his many other wonderful images. But take a minute and just enjoy a full-screen version of the picture -- you are seeing the same process of star birth that gave rise to our Sun some five billion years ago.
Wednesday, July 24, 2013
An international team of astronomers has found a new kind of astronomical event in the universe -- a powerful flash of radio waves, lasting only a few thousandth of a second, but coming from vast distances away.
Radio waves -- the same kind of invisible "wireless waves" that bring news of traffic jams to our car radios or wifi for our laptop computers -- come from a variety of natural events in the cosmos. If your car radio were to convert them to sound waves, they would sound like static. Radio static comes to us from the magnetic regions of the Sun and Jupiter, from remnants of exploded stars, and many other sources in the sky. But the "transmissions" usually last a long time.
A sudden burst of such waves lasting only a few thousandth of a second (and then never again) came as a surprise to astronomers. The first of these was discovered six years ago, but was classified as doubtful until others could be found. Now astronomers have found a total of five from different directions in the sky. Indications are that they come from far away -- from far beyond our Milky Way Galaxy. If so, and we can still detect them from Earth, they must be very strong bursts indeed. (In the same way, if you scan the horizon and see a flash of light from a distant city, whatever made the light must be quite bright to cross the space between cities and still be visible to your eyes.)
What could make such brief, super-strong bursts of radio waves? It must be something small and powerful. First candidates include the collapsed corpses of stars that are called neutron stars. These are what remains of stars that exploded long ago, and they can pack more than a Sun's worth of material into a ball no bigger than a suburban town (about 20 miles across!) When such densely packed star corpses collapse further or have a magnetic hiccup, they can give off a quick shot of radio energy.
But at this point, no one really knows what sorts of cosmic objects the radio bursts come from and we are eagerly searching for more. This situation is very similar to what happened in 1967 with another kind of invisible wave, called gamma rays. A secret spy satellite found a few bursts of gamma rays coming from space. At first, no one could figure our what they were and why we saw them randomly around the sky. But as decades passed, and we detected more and more of them, with better and better instruments, we learned a lot more about them and began to come up with really good explanations for these "gamma-ray bursts." We may be at the beginning of a similar era of further exploration and gradual explanation with these radio bursts. As they say on the radio, "stay tuned."
(The artistic image with this post shows the radio telescope in Australia that found the new bursts, together with a blue dot symbolizing the (invisible) burst, some distance away from a map of radio waves coming from our own Milky Way, shown with reddish colors. So only the color of the telescope is real, the other colors try to show things our eyes cannot see, using colors we can see. But how else can we have a nice picture with the story?)
Saturday, July 13, 2013
I just got back from a fascinating conference in New York on how astronomy has inspired other fields, like art, architecture, poetry, and music over the years. I was the after-dinner entertainmen...I mean...the banquet speaker and had a chance to share the results of my 30-plus years of collecting examples of astronomical music (assembled with the help of many generations of students).
Composers of both classical and popular music have long been inspired by the ideas and discoveries of astronomy. The picture with this post, for example, shows some sheet music from 1901 that was inspired by physicist (and inventor) Nikola Tesla's claim that his early radio equipment had intercepted signals from our neighbor planet Mars. Actually they turned out to be perfectly natural radio waves from the upper layers of the Earth atmosphere, but for a while the news media were touting the idea that martians might be signaling us.
If you want to see my full list of 133 "astronomy music" pieces that you can find on CD, it's at:http://aer.aas.org/resource/1/aerscz/v11/i1/p010303_s1?view=fulltext
With the growth of videos on YouTube and other web sites, you can actually watch some of these pieces being performed. Among my popular-music favorites on video are:
1) "Walking on the Moon" by the Police (comparing the feeling of being in love to being on the Moon's surface):http://www.youtube.com/watch?v=gPpvHEsC_PM
2) "Hawking" by Todd Rundgren (which tries to put the listener in the body and mind of brilliant but wheelchair-bound physicist Stephen Hawking): http://www.youtube.com/watch?v=jk7uZO1iED8
3) "Why the Sun Really Shines" by They Might Be Giants (a children's song): http://www.youtube.com/watch?v=u-KyciKHw-g
4) And, for a change of pace, the "Elements" song by 1960's humorist (and math professor) Tom Lehrer:http://www.youtube.com/watch?v=AcS3NOQnsQM
A number of brave composers have put together musical pieces that are based on the rhythms or tones of actual astronomical observations. There is music based on radio signals from galaxies, on the index of how the Sun affects the Earth's magnetic field, and on the speed with which the planets orbit the Sun. A fun recent example is "Supernova Sonata" -- music based on a catalog of newly discovered exploding stars in other galaxies:http://vimeo.com/23927216
I have enjoyed collecting these musical examples of the power of astronomy to affect our imaginations and hope you enjoy hearing some of them.