August 20, 2009

District 9: Prawns from a Planet with Seven Moons

prawnThe young little prawn is endearing. The scene where he was curiously studying about his home planet is my favorite. Learning that they come from an exoplanet with se7en moons make me a happy camper, too. I would love to hang out with that cute little prawn and learn more about their planet which I speculate is earth-like in many respects. The temperature, atmosphere, terrain and gravity of their home world must be quite similar to Earth's, otherwise the prawns would not survive here if their planetary characteristics were any different.
District 9 is like a comic book, more enjoyable when viewed as such. Many loopholes in the plot are over-ruled by great cinematography. I'm only nagged by a single question of why the humans treated the aliens unintelligently. One would have naturally dealt with these prawns in a civilized way, as one would treat any visitor. Nevertheless, the movie gives homage to the directing prowess of Neill Blomkamp.
The movie will prove to be a great discussion for Xenosociology, the study of Alien Cultures and their social behaviours. It gets steamy when they interact with Humans in a complex setting (apartheid) where the dark elements of the human psyche is displayed. The aliens themselves are reduced to high-tech scavenger bugs.
It makes one think whether an Advanced Technological Civilization would make a race "civilized" at all. However, the drama that ensues manages to reveal the virtues common to both species.
District 9 is a neat little package that gives the freedom to draw one's own metaphors from. It is a great Sci-Fi movie that will reverberate in our culture for quite a while.

August 18, 2009

The Big Dipper and Exoplanets

Big Dipper ExoplanetsAs of today, August 2009 the total number of known exoplanets stands at 373. Almost every month or every week, there are new exoplanets being discovered.
Pretty soon, exoplanet discoveries will be a regular occurrence that it becomes an ordinary thing. After all, exoplanets may be as "common as table salt", and they are numerous as grains of sand on the beach.

And then people might begin to lose the wonder of it all.

Amidst the accelarating rate of discoveries, I hope that we never lose that sensawunda. That is why it is important to know the exoplanets in the skies. We must be able to point at the stars and say to someone, "Look! Right there is another world!"

What better way to start with the exoplanets in the most-recognized pattern in the night sky--The Big Dipper. The Plough or the Big Dipper is an asterism that is a part of the constellation called Ursa Major. As you stare at the Big Dipper, you may actually be gazing at exoplanets as well. Light that passed through the horizon of another world may actually reach your eyes. Feeble as they may be, the photons of light from other stars carries information about the planets they harbor. Light is the medium by which scientists examine the atmosphere of other worlds. Of course they use instruments that are a millions of times more sensitive than our eyes. And these photometric instruments gather starlight far more efficient than our retinas.

Within the field of view of that big scoop in the sky, there are currently ten eleven exoplanets (as of 03/09/2010) discovered so far. Well, none of these "Big Dipper Exoplanets" orbit the stars of the actual Big Dipper shape, but they belong to the stars within the Ursa Major constellation. We simply use the Big Dipper as a guide.

Among the noteworthy ones of these "Big Dipper Exoplanets" are 47 Ursae Majoris b, the first exoplanet to be discovered within Ursa Major in 1996. It was followed by it's sibling 47 Ursae Majoris c in 2001. Their parent star with a magnitude is 5.1 is visible with the naked eye. Then there's HD 80606 b, a superjovian planet with the most highly-eccentric orbit known so far. HAT-P-3 b is the easiest to find as it lies near Alkaid, the tip of the Big Dipper's handle. HD 118203 b lies close to it near the first joint of the handle.

The rest of them is scattered away from the plough. More information can be accessed with a link via the list below. A KMZ file is also provided for use via Google Sky. And a data set view is set up in Freebase such that any new exoplanet entered with a constellation value of Ursa Major will be automatically included in that data view.

Although at this time the list is tiny, we can expect this list to grow in the coming years. Perhaps the Big Dipper may become so full of exoplanets that it wouldn't be big enough to contain them all.

August 15, 2009

How To Know an Exoplanet's Orbit

The Rossiter–McLaughlin effectOne can never get enough of oddballs. A new exoplanet named WASP-17 b was found orbiting the wrong way relative to the direction of it's star's rotation. It is on a retrograde orbit.
Typically a star's spin, as well as the orbital motion of all it's planets go in the same direction of the swirls of the primeval gas and clouds from which they formed. This is the case with our own solar system--but not so with WASP-17, which is the first star system known with a planet orbiting in an odd way.
The story says that a violent collision with another massive rock sent the WASP-17's planet flying off in the other direction.
But how did the Astronomers find out about the direction of WASP-17b's orbit in the first place? A transit light curve alone does not tell whether an exoplanet passes across it's star from left to right or vise-versa.
It turns out that the WASP Team needed help from the planet hunters at the Geneva Observatory, who specialize in Radial Velocity (RV) measurements.
Here's the low-down on how Radial Velocity was used for WASP-17b which was primarilly a transiting exoplanet, "astronomers can identify the direction of a planet's orbit because of slight discrepancies in the radial velocity data when a planet transits a star. Because a star is rotating, one side of it is moving towards (or away) from Earth faster than the other side. During a transit, the planet covers first one side of the star and then the other, causing a slight but measurable shift in the radial velocity readings. If during the transit the star first appears to be moving relatively slowly towards the Earth, but then faster as the transit progresses, then the planet is orbiting in the same direction as the star's rotation. But if the reverse is the case – as it is for WASP-17 – then the planet is in a retrograde orbit."
That description is actually the The Rossiter–McLaughlin effect, and it was also mentioned to me by the twitter hive mind. I think The Rossiter–McLaughlin effect is the key part in understanding how to find out an exoplanet's direction of orbit. It's a phenomenon that weaves together the elements of the Doppler Shift, the star's wobble and Photometry.
It seemed counter-intuitive for me at first, knowing that the Transit Method used to find WASP-17 b is primarily used for detecting exoplanets from star systems whose orbital plane is edge-on with our view. While Radial Velocity (RV) I thought was used only for non-transiting exoplanets--whose orbital plane is not edge-on with our line of sight.
But now i realized that the planet-hunting methods can be used in tandem as "Planet-hunting Mash-ups" to make novel discoveries, as what happened with WASP-17b.
It's truly great to know that now we can find out the direction of an exoplanet's orbit, no matter how odd it is.

August 13, 2009

The Perseid Exoplanets

Perseid ExoplanetsFor yesterday's post, I painstakingly scoured the web for the known exoplanets that belong to the Perseus Constellation. Perhaps I should coin the term "Perseid Exoplanets" (in relation to the Perseid Meteors) for easy reference during the annual Perseid meteor-watching and exogazing activity.
And so with this post I gladly introduce the Perseid Exoplanets, along with some useful resources.
First is a printable image showing the location of the Perseid Exoplanets, along with the approximate location of the Perseid Meteors' radiant. Next is the KMZ file for Google Sky which i used to generate the image.
Then here's a view of their data on Freebase. Whenever someone enters data of any new exoplanet discovery within the Perseus field it will automatically be added to this list on Freebase.
Finally, below is a copy-paste friendly list of their locations in the sky via RA and Declination.
HD 17092 b 02:46:22,49:39:11
HD 23596 b 03:48:00.3739,40:31:50.287
HD 16175 b 02:37:01.9110,42:03:45.479
WASP-11b/HAT-P-10b 03:09:28.55,30:40:24.9

So what are you waiting for?! Print out these resources and go out there and start Meteorwatching and Exogazing!
Clear skies!

August 12, 2009

Meteor-watching and Exogazing

Perseid MeteorMid-summer August marks the peak of the Perseid meteor shower. And it is an amazing sight to see meteors streaking across the starry night sky. Meteor-watching is a very exciting activity especially if you are seeing "shooting stars" at the rate of ~20 per hour. But did you know that there is another cool activity you can do while waiting for the next streak of meteor across the same patch of sky?
That activity is called Exogazing. It is the process of locating particular stars which is orbited by known exoplanets discovered by planet-hunters.
Did you know that in the field of view around the radiant of the Perseid Meteors, there are several stars that have known exoplanets orbiting around them? In fact, in the constellation Perseus, we currently have 4 exoplanets namely HD 17092 b, HD 23596 b, HD 16175 b and WASP-11b/HAT-P-10b. There may be more, and here's several among the surrounding areas, namely within the constellations Cassiopeia (HD 17156 b, HD 7924 b), Camelopardalis (HD 33564 b), Auriga (HD 49674 b) and Triangulum (HD 13189 b). Some meteors streaks, which seems to emanate from the radiant will actually pass across these constellations in your field of view (FOV). Check out this nice simulation of the Perseid Meteor Shower at Shadow and Substance.
So it'll be fun that while you are watching for meteors in the surrounding area of the Perseus Constellation, you can actually try to pinpoint stars with discovered exoplanets and then tell your friends that those stars have planets around them.
Be warned though, that the stars of these exoplanets are quite faint and you probably need binoculars to exogaze at some of them. It may limit your view but if one happens to streak across your FOV, the sight would be fantastic if you follow the meteor with wide-field binoculars.
With the "Perseid Exoplanets" mentioned in this post, you can make your own list, perhaps add some more from the constellations Taurus or Andromeda. Then choose which ones are the brightest and suitable targets to begin with.
Good luck with Meteor-watching, and have fun Exogazing. May you have clear skies!

August 6, 2009

Yay! Kepler Works!

light curveEven though twitter was mostly down for the important announcement of the Kepler Mission, it did not dampen the excitement surrounding the update.
Kepler Works!
To prove it, the Kepler team produced a lightcurve of a previously known exoplanet, HAT-P-7 b, and found that Kepler's findings agree with previous observations of that planet. Oh, but there is so much more!
A cleaner light curve means that Kepler's data has less noise than those gathered by ground-based telescopes, which means more precision, and thus proves that Kepler is truly capable of detecting earth-sized worlds.
Most of all, Kepler's precision allowed the team to detect the atmosphere of a known gas giant planet. Based on the light curve, the trailing small dip corresponds to the occultation of HAT-P-7b--the part where the planet "hides" behind it's star. Taking this in consideration with the actual transit curve (the first major dip), the depth of the occultation and the shape and amplitude of the light curve show the planet has an atmosphere with a day-side temperature of about 4,310 degrees Fahrenheit. The occultation time compared to the main transit time also shows that the planet has a circular orbit.
All these bonus information is simply amazing! Not only does Kepler work, it works beautifully! Therefore, the Kepler Mission Team deserves a great commendation! And I'll drink to that! Yay! Kepler Works!

Links: Kepler Press Release

August 3, 2009

A Star for All Ages

VB 10In May of 2009, the discovery of a giant jupiter-like planet named VB 10b made headlines as the first planet discovered via the method called Astrometry. It is mentioned, but not given much emphasis that the the host star of VB 10b is the smallest star ever to be found harboring a planet. However, beneath this headline is an even more remarkable fact: VB 10 will outlive most stars in the universe.
Stars that small are very stingy with their energy production, they burn fuel ever so slowly. This is a striking contrast with the supergiant star Betelgeuse that used up most of it's fuel so quickly in a short time that it's now about to go nova.
Aside from being a long-lasting star in itself, VB 10b will actually use it's companion planet as an energy source in the future when VB10b tightens it's orbit and moves closer to it's sun. Yes, VB 10b is literally a "spare gas tank" for it's parent star. Greg Laughlin says, "The planet's gas will be a shot of fresh hydrogen to VB10 and should give it enough fuel to burn another 100 billion years -- basically forever."
And when we say forever, in this context it means close to the end of the universe, perhaps the last age of the cosmos where entropy has almost taken over, long after most other objects have faded into darkness.

August 2, 2009

Under The Frozen Sky

Herzog's FilmThe past week, I've been watching bits of Werner Hertzog's documentary called "Adventure at the End of the World".
In the segment "Under The Frozen Sky" of this rare film, it shows what it looks like below the frozen ice of Antartica.
Beneath the ice and under the "frozen sky" is an other-worldly landscape home to uncanny creatures that thrive within it's extreme cold. It's a place where the "clouds" are bubbles of air trapped underneath a bluish ceiling, sliding like mercury along the contours of the ice.
My growing desire to glimpse other worlds and lifeforms mesmerizes me whenever I learn about new wonders of Earth. Antartica is a wonderful place. But at one point the film mentioned that the challenge of human adventure and our thirst for the unknown seems to have ended in this cold desolate part of our planet.Jellyfish
"On a Cultural Level, it meant the end of adventure" when the last unknown spots of the earth was exposed and "Human adventure...lost it's meaning", the narrator says.
I felt a certain sense of bleakness at this thought.
However, when Herzog mentioned that Antartica "comes closest to what a future space settlement would look like", I sprang with renewed enthusiasm. And this enthusiasm was fed further by the timely arrival of Apex Magazine in my mailbox yesterday. Upon which my attention was immediately caught by Jeff Carlson's novelette curiously entitled "The Frozen Sky".
It was set in the sixth moon of Jupiter, Europa.Apex Magazine
And when i began reading it, I couldn't stop. The narrative blended so well with the science behind a world yet to be explored. It gripped me, a world with a crust of thick ice, possibly riddled with exotic alien lifeforms hidden underneath. Suddenly, the scenes from "Under The Frozen Sky" played back in mind.EuropaThe Frozen Sky is an example of the kind of science fiction that I want to read in the coming era of exoplanet discoveries. Soon I hope to read stories where the exoplanetary world used as a setting is given as much personality as the characters themselves. And I would like the science behind the story to be imaginatively elegant, so as to be almost theoretical.
Narratives have that amazing quality to educate and to inspire. And it would be great to start a cycle of ideas flowing between new exoplanet discoveries and science fiction. Imagine all the new inspiration it would bring for space travel, for human adventure, and desire for discovering new wonders.

August 1, 2009

The Sonneteer Ponders Habitable Exoplanets

SonneteerI recently had a very pleasant surprise when a Sonneteer accepted a 'sonnet dare' that i posted to her via twitter. I was curious as to how Kate Sherrod the poet behind the typewriter at SupperTime Sonnets--would render the sociological impact of exoplanet discoveries.
And sure enough, I got a wonderful sonnet entitled "In Which I ponder Habitable Planets".
This sonnet expresses the most poetic question ever for planetary science:
"Is earth unique as an abode for life like ours?"
But the best is yet to come. I was not aware that Kate would actually read the sonnet herself! And what a soothing voice I heard when i listened to her KateofMind podcast!
Kudos to Kate for a nice sonnet-rendition of the idea that some folks would still not believe it even if Kepler discovers far-away earth-like worlds. After all, she says--there are still naysayers of the moon landing even after the LRO recently snapped photos of Apollo 11.
Thus, whether Kepler finds Habitable Planets or not, we can still enjoy the sonnet as I did!

In Which I Ponder Habitable Exoplanets

In March the Kepler probe began to seek
The subtle signs of planets far in space
That circle other stars. Is Earth unique
As an abode for life like ours? This place
Which some believe's created just for us
Might not be all that special, all that rare.
But then I ponder on Copernicus,
Who laid the Ptolemaic theory bare
And proved to all the Earth goes round the sun.
It took hundreds of years before some folk
Accepted this, unbanned his book and one
Suspects that out there still, like some great joke
Are people who'll insist his work's all lies
And exoplanets naught but fireflies.