February 23, 2009

Is Pluto Truly a Planet? Exoplanets Give Insights

What do exoplanets got to do with Pluto? Everything!
Exoplanets "out there" may actually decide the fate of our poor Pluto, who has been the subject of much heated debates.Pluto As everyone knows, Pluto is no longer considered a planet by the IAU. Why? Because some folks decided that a planet must satisfy three conditions to be considered as a planet:
1) It must orbit a star
2) It must have a round shape
3) It must clear its path of any other object.
Now the third condition is where Pluto fails as a "legitimate" planet, IAU says.
But that's where the newly-discovered exoplanets enter the picture: The discovery of a pair of exoplanets named HD 45364 b & HD 45364 c, the third condition may come under question more than ever.Neptune
HD 45364 b|c actually share orbits at times! Their orbits sometimes touch and may even overlap. They don't collide because they have resonant orbits. They revolve around an orange dwarf star named HD 45364 in the constellation of Canis Major, about 110 light years from Earth. The inner planet completes three orbits around its star in the same time it takes the outer planet to complete two orbits (3:2). Therefore, the inner planet at times lies further from the star than the outer planet--just like Neptune and Pluto.
Both of HD 45364's planets are giants; the inner planet is at least 3.5 times the mass of Neptune. The outer planet is more massive, at least 2.2 times the mass of Saturn. Now if we stick with the IAU's definition, neither of these objects would be considered planets, as they do not "clear their orbits" of one another.Pluto and Neptune Orbital Resonance
The IAU might have made a terrible mistake of deciding too early and hastily declaring a definition of a planet before even considering what might be "out there"--that perhaps we need more samples of other solar systems before deciding what a planet is or is not.
I remember the mantra of Murray Gell-man, about the beauty of things. Truth and Elegance often displays beauty. In my opinion, the third definition of a planet invented by IAU was not pretty. And the havoc and embarassment it wreaked upon the Astronomy community is really quite ugly.
Frankly, I don't see any problem with the number of planets ballooning to thousands if Pluto opens the floodgates to Planethood. It's the petabyte age, baby! Perhaps it's much simpler to see things in large numbers.
Personally, I am prepared with the list of planets or exoplanets numbering up to billions. I'll be long gone by the time the exocatalog even hits six figures, but it's inevitable. The night sky and outer space is a whole database waiting to be known. There's no need to be scared of numbers.
At times, simplicity can be achieved by looking at sheer numbers. But complexity arises with too little data (Talk about paradox!). So in our case, IAU decided what a planet is based on one sample: Our Solar System.
Even as the wonderful International Year of Astronomy unfolds for 2009, Pluto is truly living up to it's name as one of the alternate names of Hades, the Greek god of the Underworld. Pluto is truly having a blast.
With enough exoplanet discoveries, it would soon turn out to be such a simple thing to re-define what a planet is.
"Wanderer" is a pretty good word to begin with, don't you think so?


February 14, 2009

Additions to Exoplanets in Binary Star Systems

Binary Star SystemI was in the process of writing a post about true binary systems with exoplanets when I was alerted to a very interesting article. It seems that we have new additions to the list of exoplanets that belong to a binary system or multiple star system.
High-resolution imaging of 14 exoplanet hosts stars revealed stellar companions to three of the targets (WASP-2, TrES-2, and TrES-4), the latter two of which have not been known to be multiple before. This means that TrES-2 and TrES-4 will join the list of exoplanets orbiting a host star that is part of a multiple or binary star system. We know that Tau Boo b is a member of this list.
This new findings has resulted in new parameter values for the three exoplanet host stars. Also this new knowledge about exoplanetary binary hosts could contribute to the evolving study of planet formation. The presence of a binary companion could very well influence the planet formation process as well as the predominant migration mechanism.
The amazing thing about binary star systems is that any planet in that system will have two suns.
Let the glorious scene of an amazing sunrise or sunset come to your mind. The sunset of a single sun is already breath-taking. What more of two suns?
Two Suns

ONE DAY - Björk

One day : it will happen
One day : it will all come true
One day : when you're ready
One day : when you're up to it

The atmosphere will get lighter
and two suns ready to shine just for YOU
I can feel it!

One day : it will happen
One day : it will all make sense
One day : you will blossom
One day : when you're ready

February 6, 2009


I would like to introduce a new hobby: It's called Exogazing.
Exogazing is like stargazing, except that aside from gazing at the stars, you also gaze at exoplanets. Well, you don't really see the actual exoplanets, but in theory the photons of light that grazed past a transiting exoplanet's atmosphere might reach your eyes. Because as you gaze at a star that hosts a transiting exoplanet, the photons of light that contain some information about the exoplanet may make it to your retina. But too little amount of these photons is not enough for our eyes to perceive it. Most of what our eyes see is the star (but with much better instruments to collect light, you can find out more about an exoplanet's atmosphere--as what scientists do, with the method called Photometry) Exogazing is simple and requires minimal instruments. Anyone can do it.

Exogazing is a contraction of the phrase "Extrasolar Gazing", a term in line with the usual "stargazing". In essence when we look up in the night sky, we are mostly gazing at objects outside our solar system. But "exogazing" is deliberately identifying the location of an exoplanet in the night sky as a pinpoint of light by it's host star.

Exogazing also comes from "Exoplanet Gazing", a term indicative of the wonder and fascination of Extrasolar Worlds. But in relation to actual planet-hunting which involves trying to detect yet-undiscovered planets around other stars, Exogazing is simply gazing at star-filled constellations and "spotting" for which stars have known exoplanets orbiting around it. Exogazing can be considered as a step prior to Exoplanet Observing.

When the discovery of Fomalhaut b via Direct Imaging came about, I was inspired. To look upon a star, knowing that there is a planet orbiting around it, gives me that Exoplanetary Thinking effect.

The idea of being able to point at a star visible to the naked eye, and tell others about its planets has got me hooked. I love telling my kids about these exoplanets as I point toward their direction in the night sky--at the actual host star, in a familiar constellation. And I would love to stir their imagination about other worlds. What better connection to a young mind than to actually stand beside a child and then point at an actual star with a confirmed planet orbiting around it? It's Astronomy, Science, Imagination, and Inspiration at it's best!

The Method.
To identify and pinpoint the actual star that hosts the exoplanet is the basic task of Exogazing. It's simple. It starts with a simple question, "Which stars have confirmed exoplanets?" Then a little challenge of star-hopping and occasional use of "pointers" makes it all the more fun. Heck, you might even come up with your own directional pointers specific to exogazing.
Currently, there are only few stars visible to the naked eye that have confirmed exoplanets. But a number of some exoplanet-hosting stars are quite faint thus you need a binocular and a starchart to locate them in the sky. Star-hopping is often necessary to avoid getting lost in your field of view. And once you locate the star that hosts the exoplanet, let your eyes gaze upon it for a while and feel free to enjoy the wonderful moment of knowing the fact that this particular pinpoint of light reaching your eyes contain other worlds.

Other Benefits.
Exogazing is a good hobby to allow you familiarize oneself with the stars and constellations, or Astronomy in general. Having a goal in mind, such as trying to locate faint stars which host planets stimulates learning, and enhances information-retention.

And for hopeful amateur astronomers who may eventually join the ranks of that amateur group who will someday contribute to the discovery of new exoplanets, Exogazing is a perfect introductory activity to get familiarized with planet-hunting or exoplanet observing.

Basic Instruments.
Now what instruments do you need for exogazing?
Here are the basics:
Planisphere, starcharts, binoculars, music.

Exogazing Music - I value the human experience, and you need to experience the wonder of the stars. Music is a much-needed factor to complete the experience. I highly recommend songs that have no lyrics, so as to let the stars sing to you in their own "voices". The genre of post-rock or electronic chill works best for me to get that mood and "spiritual" experience. [UPDATE: A new genre has sprouted from this: It's called "Exogazing" music] Besides, there should be a reason why star-parties are called the way it is, so i think Music should definitely be a part of it.
Star Catalogs - Some more challenging stars that are too faint, may require you to consult a more detailed catalog of stars.

Optional Instruments.
Tripod-mounted binoculars would be great but if you want an enhanced experience, an Image Stabilized (IS) binocular will be a great option. Part of the telling factor of exogazing is the human experience. The image stabilization feature eliminates the jittering and makes exogazing a wonderful experience, specially when you often need to pan to-and-fro across the sky as you "star hop" to make your way to the target. So the agility of hand-held binoculars are highly-recommended.
Laptop - You might need it to access updated information about the exoplanets you are gazing at, or to consult astronomy software such as Stellarium or Google Sky. As an option, you may need it to contribute your findings to the open database at Freebase, or to connect to last.fm to play the recommended exogazing music. :)
Green laser pointer - For helping others star-hop in the sky & Instructional purposes
Red flashlight - For checking charts in the dark and preserving night vision

Basic questions.
You need a few basic questions to get you going, which starts with "Where are those doggone Exoplanets?" The rest will follow: What constellations are up tonight? And which visible stars within those constellations have confirmed exoplanets? What are the exoplanets that belong to a particular constellation? What is the type of star of a particular exoplanet? What type of exoplanet is it? How far is it? Is it habitable?

There will be more Exoplanets to come. And so Exogazing will become ever more fun in the near future. May it serve as the start of a fun new activity for all Astronomers (Amateurs and Professionals alike) in their stargazing nights. And I hope that the Amateur Astronomy community would love Exogazing during star-parties as well!
I will continue to share my Exogazing sessions and open up a section in the Exoplanetology website dedicated for this hobby. I will also continue to tweet and write about it in this blog. So stay tuned!
Happy Exogazing! And Clear skies!

February 4, 2009

The Monster & The Beast of Exoplanetology

A little monster ferret that came to our family when exoplanets were all the rave. I almost named her "Exo", but spouse vehemently protested.
I woke up this morning with the voice inside my head : Exoplanetology is a monster.
Then I opened my eyes. And there it was staring me in the face.
Apparently, its not only the Art and the Science of exoplanets. We also need to consider the technology behind exoplanet research. We use computers and software to model exoplanets. We use simulations and visualizations.
We also have the data aspect behind it. In the coming years, petabytes of data will be beamed from high-end telescopes such as Kepler and James Webb Telescope. Such a thing is not to be ignored.
Exoplanet research also involve instruments. Highly technical instruments like new CCD's & astrophotonics. And then it begs the question of how planet-hunting will fare as a subset of Professional and Amateur Astronomy. Will a new class of "affordable" telescopes be developed specifically tailored for exoplanet-hunting?
Then there's the aspect of Thought. How does the discovery of earth-like exoplanets impact the prevailing human worldview? How does the discovery of extra-terrestrial life affect religions? How does the idea of new worlds out there impact the life and culture of society?
As one may realize, the Thought behind Exoplanets reaches all the way to Philosophy and Theology. And it makes me realize that an exoplanet lightyears away may not have any gravitational influence on earth at all. But the knowledge of it has plenty of impact on the human mind and psyche.
And it brings us to the most important beast: How do exoplanets impact the life of a single human being?
My eyes are wide open.
The challenge of Exoplanetology beckons.
The monster awaits.

February 3, 2009

Walking on Super-Earth CoRoT-Exo-7 b

The suspense is over. Here is the latest Exoplanet Discovery: CoRoT-Exo-7 b. This discovery via transit method is not of an earth-like world just yet. But at least it's a super-earth because it's almost 11 times the mass of earth. And it's a little bit bigger than earth as well, having almost twice the earth's radius.
Now, in contrast to the recently reported exoplanet (HD 80606 b) which has a very eccentric orbit 0.927, CoRoT-Exo-7 b in turn has an almost perfect circular orbit around it's K-type star, having an Orbital Eccentricity equal to zero.
Now, with an orbital period of just 0.85 days or 20 hours, it must be whizzing around it's star so fast and mighty close to it's star. Hence it has a high temperature, between 1000 and 1500°C, still scorchingly hot by my standards.
I'm guessing that it might be tidally locked - meaning only one side faces it's sun. On the other hand, it could be spinning so fast, so my guess could go in both extremes.
Reports say that it is a terrestrial rocky world, and one can walk on it's surface, they say. Although, getting someone to get there and do it is another story, it is quite interesting to think about.
For starters, I would weigh a lot heavier in that exoplanet, and so I will get increasingly tired with each step. Upon which case, my foot would sink deep into it's molten lava surface. And the heat would be quite unbearable. And assuming it spins fast, day and night would alternate so much quicker than what i am accustomed to. However, if it was tidally locked, I would rather be on it's "dark side" because it's probably be much cooler in that region of the planet.
I might skip the stroll on this super-earth and take my chances on the discovery of an earth-like world soon, where it would be like a walk in the park.

CoRoT-Exo-7 b
Radius: between 1.75 and 2 Earth radius
Orbital period: 0.85 around a K star (T= 5300K)
Orbital Eccentricity: 0
Mass: less than 11 M_Earth

ESA News Release
CoRoT-Exo-7 b on Exoplanet Encyclopedia