Hubble
esiegel | May 14, 2010"I may be an old lion, but if someone puts his hand in my mouth, I can still bite it off." -Wilhelm Steinitz
When you look at a typical galaxy, you usually find a disk, a bulge, and a few dots diffusely strewn about the exterior.
Like an old lion, these dots have been around for a very long time: often for longer than the galactic disk itself! Just what are these things? Well, we can learn a little more if we look in the X-ray (with Chandra) and the infrared (with Spitzer), in addition to a visible light image (from Hubble). Let's take a look at a composite:
Just what are these dots that…
esiegel | April 30, 2010When I had satisfied myself that no star of that kind had ever shone before, I was led into such perplexity by the unbelievability of the thing that I began to doubt the faith of my own eyes.
-Tycho Brahe
One of the great things that the Hubble Space Telescope has given us is a whole slew of images of supernovae and remnant of past supernovae, from recent ones like SN 1987a
to supernovae that are hundreds of years old, like Tycho Brahe's supernova from 1572. In fact, Hubble is so powerful that it actually found the companion star that resulted in the Supernova exploding in the first place!…
esiegel | April 23, 2010Where there is an observatory and a telescope, we expect that any eyes will see new worlds at once. -Henry D. Thoreau
20 years ago tomorrow, the Hubble Space Telescope was launched into orbit.
It doesn't look that impressive, and maybe it shouldn't. After all, what is a space telescope? It's a couple of mirrors, a camera, some stabilizing gyroscopes, some electronics and an antenna, all wrapped in a reflective coating and powered by some solar panels. Doesn't sound so hard, does it?
But Hubble has vastly increased our understanding of the Universe, and I'd like to share with you some of the…
esiegel | February 4, 2010What we know about Pluto today could fit on the back of a postage stamp. -Colleen Hartman
Part of the joy of astronomy is, every once in a while, you just get an astoundingly beautiful new picture or video of a foreign planet, star, galaxy or cluster. Pluto, the most distant planet, is among the most elusive.
This picture above was snapped by the Hubble Space Telescope about a decade ago, and shows us Pluto (center) with its large moon Charon and its two smaller moons, Nix and Hydra.
It's pretty difficult to get better resolution pictures of that planet because Pluto is both so far away and…
catdynamics | January 6, 2010more invaluable science nuggets and pretty pictures
The Galileoscope is a very cheap but functional 50mm astronomical refractor kit for introducing kids to optical observing; NB PRICE GOES UP NEXT WEEK!
They can also be donated - through an online click.
But, now Ric and Jean Edelman of Edelman Financial Services have donated $250,000 to the AAS to buy and distribute 15,000 Galileoscopes for distribution to teachers around the US for use in classroom.
Nice one.
Hm. Y'know Goldman Sachs could go a long way towards repairing their public image with a token $250,000,000 donation towards a…
catdynamics | December 22, 2009Set the focus on infinity!
A new one from the photomixers...
"I need a space telescope,
ain't got time to wait"
...
"My mind is busting,
and I got a PhD!"
esiegel | December 16, 2009Before you were conceived I wanted you
Before you were born I loved you
Before you were here an hour I would die for you
This is the miracle of love. -Maureen Hawkins
But I'm not talking about human children, I'm talking about the children of the stars. Stars burn their fuel until they no longer can, and then die in one of two impressive ways, depending on how massive they are. If a star is up to around four times as massive as our Sun, it dies by collapsing down to a white dwarf and blowing off its outer layers into a planetary nebula.
On the other hand, if your star is very massive -- like…
esiegel | December 11, 2009Earlier this week, I showcased the newly-released Hubble Ultra Deep Field in the infrared, and compared it with the older image of the same region taken in visible light.
As many astute readers noticed, the newer image looks blurrier than the old one! This is true, and there's a good reason for this. Here's one of the old images from the Ultra Deep Field (in visible light):
and here's that same region in infrared light.
Yes, the latter image is blurrier. Why is it blurrier? One of the biggest differences between infrared light and visible light is their wavelengths; visible light goes from…
esiegel | December 9, 2009They will see us waving from such great heights
"Come down now," they'll say.
But everything looks perfect from far away
"Come down now," but we'll stay. -Postal Service
We've been over this twice before, but here's a refresher on how you image the farthest galaxies in the Universe. Pick a spot in the sky that's empty. What does empty mean? When you look with your eyes, with binoculars, and even with a reasonable telescope, you find no bright stars, no bright galaxies, no nebulae, no clusters -- in short nothing -- except for the absolute faintest of objects.
You know, something like this…
esiegel | December 8, 2009Have you been keeping up with The Boston Globe's Hubble Advent Calendar? Today's picture is totally worth talking about, and gives me a chance to tell you about these little guys that just hang-on to our galaxy: globular clusters. When you look out at a galaxy -- pretty much any galaxy -- you'll find these tiny clumps of light surrounding it.
These clumps are actually amazing, dense collections of stars! If you look out at the nearest star to us, it's Proxima Centauri, located just over four light years away. That means if you drew a sphere centered on the Earth four light years in radius,…
esiegel | December 1, 2009At the last dim horizon, we search among ghostly errors of observations for landmarks that are scarcely more substantial. The search will continue. The urge is older than history. It is not satisfied and it will not be oppressed. -Edwin Hubble
Hubble didn't need a thousand words to describe how beautiful and wondrous the Universe is, and the Hubble Space Telescope can -- perhaps -- say even more in just a simple picture.
Well, the Boston Globe, starting today, has a full 25-day advent calendar of Hubble pictures, which it reveals one of per day. Today's? (And click to enlarge.)
Planetary…
esiegel | September 11, 2009Perhaps my favorite of the new Hubble pictures is this one of Stephan's Quintet (and click here for the 1000 pixel wide version):
It's so stunning that it was chosen as today's Astronomy Picture of the Day. But yesterday, I got a very interesting question to go along with it:
These galaxies are far away, and so we're looking at them in the past. What do they look like today, and are there still five of them?
This is a great question. First off, looking at the image, some of you will count only four galaxies. That's because there are two galaxies that are in the process of merging. You can…
esiegel | September 10, 2009Yesterday, I linked to the Hubble Site, where they've got a collection of stunning new images taken using Hubble's new camera, the Wide-Field Camera 3:
But why would you bother to go there? After all, you know that I'll just show you all the gorgeousness here! Hubble is an astounding telescope, because it's so good for viewing things that are both incredibly close and incredibly far. So here are the highlights!
First off, Hubble can take incredible pictures of our Solar System. Remember that Jupiter recently got hit by an asteroid? Take a look at the big black debris spot by the South Pole,…
esiegel | September 9, 2009Remember saying goodbye to Hubble's old camera, WFPC2? This servicing mission was months ago, now, so perhaps you've forgotten about this 19 year old telescope.
Well, the new camera, WFC3, is finally ready to make its debut. Plans include surveying the Kuiper Belt, looking at newly forming planets, better measuring dark energy, and a new, improved Ultra Deep Field of the distant Universe.
But, as always, the images are what do it for me. Take Stephan's Quintet, a group of five galaxies close together. Regular telescope? Go, and click to enlarge:
Not bad. But one of the first pictures that…
esiegel | August 12, 2009It wasn't all that long ago that I wrote a five-part series on Hubble's old camera, WFPC2. I call it "The Camera that Changed the Universe." Part 1 focused on Hubble showing us just how deep, rich, and full of wonder our Universe is. Let's remember how this happened.
The first thing we did was take a patch of sky that was relatively empty. No bright stars, no large galaxies or clusters, no planetary nebulae, just a little tiny patch of black, empty sky.
And then we point Hubble at it. And what do we do? We sit there. And wait. Collecting tiny, miniscule amounts of light. First, for minutes…
esiegel | July 15, 2009By the 1990s, we knew an awful lot about the Universe. You can check out what the greatest discoveries were (in my opinion) from the 1910s, 1920s, 1930s, 1940s, 1950s, 1960s, 1970s, and 1980s. By this point, we understood the origin of the Universe as well as we understand it today, knew about dark matter and normal matter, and were trying to figure out what the fate of the Universe was. It started with a bang (of course), with a supremely hot (~10^20 degrees), dense, and rapidly expanding state (image courtesy of Stephen van Vuuren):
We knew that there were (and are) two things going on,…
esiegel | July 8, 2009By the 1980s, our view of the Universe was pretty close to what it is today. We had confirmed the Big Bang Theory and even had some understanding of what must've caused the Big Bang. There were some mysteries around, such as dark matter, the age of the Universe, and the solar neutrino problem, but all in all, we were on pretty solid ground.
One of the things astronomers had been waiting for was a supernova to go off in our galaxy. We expect about one per century in our galaxy, and we hadn't seen one since 1604! It's 2009 now, and we still haven't seen one, but in 1987, we got closer than any…
esiegel | June 17, 2009By 1948, our view of the Universe had changed drastically from 1909. Instead of space being run by Newton's Gravity, where our Milky Way comprised the entire Universe, we had learned that space and time are governed by Einstein's General Relativity, that our Universe contained at least many thousands of other galaxies, and that the farther these galaxies were from us, the faster they moved away from us. In other words, the Universe was not only vast and full of interesting stuff, it was also expanding as it got older!
The prevailing idea of the day was the Perfect Cosmological Principle,…
esiegel | June 12, 2009Amazing is an understatement when it comes to how much we've learned about our Universe in the last century. 90 years ago we confirmed general relativity, and got a whole new theory of gravity as a result. But, we still thought our Milky Way was the only galaxy in the Universe.
There were a few types of weird objects we knew of in great detail, such as the original 103 Messier objects. There were weird, spherical clusters of stars, like M2:
There were planetary nebulae, known to be the afterglows of dying or exploding stars, such as M27:
And then there were the much-debated "spiral nebulae…