Friday, August 26, 2011

A diamond planet? I dunno..

Artistic concept of a pulsar and its tiny companion
Image Credit: Swinburne Astronomy Productions, Swinburne University of Technology
Yesterday, the news wires were alive with excitement.  Astronomers had a confirmed discovery of a planet made out of diamond!  DeBeers better load up a rocket ship and blast off!  But before we put the cart before the horse (and the cart is already halfway across the country while the horse is still munching oats in the barn), let's look a little deeper.  The likely real story is, in my opinion, even more exotic than a planet-sized diamond.

First, let's go over what the astronomers observed.  The team, headed by Professor Matthew Bailes of Swinburne University of Technology in Australia, was looking at a millisecond pulsar.  Pulsar are the remains of very massive stars that exploded as supernovae at the end of the stars' lives.  Pulsars typically contain about 1.3 times the mass of our sun squeezed into a sphere only a dozen miles across.  This is so dense that ordinary atoms cannot exist, and most of the protons and electrons that made up the atoms in the original star merge to form neutrons.  We therefore call these very dense remains of massive stars neutron stars.


Sphere: Related Content
Digg this

Wednesday, August 24, 2011

Y Dwarfs? Because they're cool.

Cool brown dwarf spotted by WISE
Image Credit: NASA/JPL-Caltech/UCLA
That little green dot in the center of the picture above may not look like much, but it is, in fact, one of the first absolutely definitive members of a predicted type of brown dwarf, the "spectral class Y" dwarfs.  It was discovered by astronomers using data from the Wide-field Infrared Survey Explorer, a satellite mission that scanned the entire sky in the infrared wavelengths of light during 2010.  The star above has a temperature of about 25 degrees Celcius, or roughly 80 degrees Fahrenheit -- measurably cooler than the endless summer heat here in Texas.  The discovery was announced yesterday by the WISE team, and an official journal article announcing the discovery has been accepted for publication in the Astrophysical Journal.  Even cooler than the brown dwarf is the fact that this paper was headed up by a good friend of mine, Michael Cushing (now a new faculty member at the University of Toledo).


Sphere: Related Content
Digg this

Friday, July 08, 2011

The last shuttle launch


I just watched the space shuttle Atlantis safely launch on the final mission of the Space Shuttle program, 30 years after I watched the first launch of the program.  30 years.  Wow.


On April 10, 1981, I was a first-grader, and my parents kept me home from school to watch the launch.  I had never seen a rocket launch.  The final Apollo moon landing happened a year before I was born, the final Skylab mission was halfway over when I was born, and I was a toddler when Apollo-Soyuz was launched.  So space travel was a foreign idea to me, and I didn't understand the fascination.  I remember seeing this ungainly machine sitting on the launch pad and telling my parents that it would never work, and that I wanted to go to school.  When the countdown clock stopped 31 seconds before launch, I laughed, said, "See, I told you", and saw a pained look on my parents' face.

Two days later, the STS-1 did launch, and again, I was forced to watch.  But as soon as the engines fired and the shuttle lifted off the pad, I was hooked.  Although commander John Young had been in space as part of both Gemini and Apollo, those missions meant nothing to me, and for years I associated him solely with the space shuttle.

Over the coming years, I read everything I could about the space shuttle and astronauts, and even subscribed to a magazine and ordered a science encyclopedia without my parents' permission. (Kids, don't do that!)  Thankfully, they paid more or less willingly for my enthusiasm.

I grew up with the shuttle program, entering my turbulent teens at the same time as the Challenger disaster.  I went to Space Camp (technically Space Academy) in 1988 and saw models of the great Space Station Freedom and second-generation shuttle-like vehicles that would be operating in just the next few years. Then I watched as these programs were cancelled, reconstituted and rescoped, cancelled again, and yet again reborn.  I watched the shuttle launch and repeatedly save the Hubble Space Telescope, perhaps its finest hour.  I took my first job as a professional astronomer at the same time as the Columbia disaster.  And now, 30 years after it began, we're finishing the space station and putting the shuttle into retirement. 

Many people question whether the money we spend on space exploration is worth the cost.  Without hesitation, I say that it is.  The space program is less expensive than many people realize; out of every $100 in federal spending, 47 cents goes to NASA.  And it's not like we are launching bales of money into space; most of that costs pays American workers and American companies for labor and products, so that money goes directly back into our economy.  Our modern economy relies on space, from satellite communications, weather satellites, and through GPS navigation, space exploration impacts our everyday lives.

And space exploration serves another purpose.  It is inspiring.  How many hundreds of thousands or millions of children are like me, inspired to study and advance technology and science by watching big, lumbering rockets atop a thin spindle of smoke and flame?  Our technology-driven economy relies on that spark of interest.
Sphere: Related Content
Digg this

Tuesday, June 14, 2011

Are sunspots going away?

A press conference today announced three research projects that suggest that our sun's familiar sunspot cycle might be heading toward a major change or even a pause.  You can read good summaries of the findings in this post from space.com and this article on Universe Today; I'll wait while you do that and then give you my first thoughts on this news.

Done reading?  Good.  First, let me state that I am not a solar physicist, and I do not claim to be an authority on the research being done.  So feel free to take my opinions with a grain of salt.


Sphere: Related Content
Digg this

A new type of supernova?

Image Credit: Caltech / Robert Quimby / Nature
Last week, a group of astronomers led by Caltech astronomer Robert Quimby announced that they had learned a few crucial pieces of information about these enigmatic sources.  This new evidence suggests that we are seeing a new type of stellar explosion, though we still don't know exactly what we are seeing.


Two years ago, I attended a conference on supernovae (exploding stars), and I blogged about weird objects that we could not explain.  In apparently blank parts of the sky, a couple of "new stars" had appeared and slowly faded away, just like supernovae.  Only these new objects changed their brightness on much longer time scales than normal supernovae, they did not appear to be located inside another galaxy, and their spectra showed weird features that could not be identified with certitude.  Many different explanations were proposed, from white dwarf stars in our own Milky Way Galaxy to carbon stars being shredded by black holes halfway across the Universe.


Sphere: Related Content
Digg this