Itty Bitty Planetary System

Astronomers are working very hard to confirm the existence of potential exoplanets identified by the Kepler space telescope. One such confirmation was made recently, and it's the "smallest" one yet!

 

KOI-961 is a red dwarf star. This means that it still has fusion in its core, but it's much smaller than the sun. In fact, it's only 13% the mass of the sun, and is slightly larger than Jupiter in size! The image above shows KOI-961 and its three planets (to scale) next to Jupiter and four of its moons for a comparison of size. KOI-961 was not originally identified by Kepler as having an exoplanetary system. Astronomers from CalTech looked at the public data released by Kepler, and saw something suspicious in the light curve. They observed this star using both the Palomar Observatory and Keck Observatory, and their results confirmed the existence of a 3 planet system! The planets masses are unknown, but their sizes are ~0.57, 0.73 and 0.78 Earth radii. This suggests that they are rocky planets similar in size to Mars. Planets 1 and 2 are too close to the star to harvest life, but planet 3 is just on the inner edge of the habitable zone! Much more work is needed before we can truly speculate the existence of life on this planet, but the more discoveries we make, the better chance we have of finding a planet just like Earth!

Image Credit: CalTech

Kepler 22-B

The newly discovered and confirmed exoplanet Kepler 22-B has made big news lately. Why? Well, it's the first confirmed exoplanet discovered by the Kepler space telescope that is roughly the size of Earth and sits in the habitable zone of it's host star! Now don't get too excited, this doesn't mean we've found Earth's twin, or that aliens exist. Being in the habitable zone doesn't imply that life actually exists there, it just means that the planet is the right distance from the host star such that it could harvest liquid water, if any exists in the system.

 Artists impression of Kepler 22-B

The star, Kepler 22, is very similar to our sun in size and composition. The planet, Kepler 22-B, is about twice as large as Earth, and sits a little bit closer to its host star than Earth does to our sun. Astronomers don't yet know anything about the planets structure or composition. Due to its size and proximity to its host star, it's likely that the planet is rocky, but we need more information to confirm that.  We also need more observations to see if the planet has an atmosphere and ,if it does, what that atmosphere is made of. One thing we must also keep in mind is that this system is 600 light-years away! At the speed of the space shuttle, it would take over 10 million years to get there! So all these news stories that suggest traveling to this planet are quite optimistic to say the least. Regardless, this is an amazing discovery, and astronomers expect to discover more planets like this in the near future. Could Kepler 22-B be very similar to Earth? Is there an alien species there? Only time will tell!

Credit: NASA/Ames/JPL-Caltech

Free Astronomy Apps

If you have an iphone or other smartphone, you've probably discovered that there are quite a few astronomy apps out there. Most of them cost a few bucks,  but there are some pretty cool free ones out there. Here's what I have downloaded to my iphone that you should check out for yourself:

Exoplanet Database: This is an awesome app if you're into exoplanets! It's a database with information about all the different exoplanets that have been discovered, and includes size, period, distance, and other useful information. You can read news about exoplanets, view where any exoplanet is located in the galaxy, make handy graphs of exoplanet properties, and even get links to scientific papers about the exoplanets. The coolest part about this app… it sends a text message to your phone every time a new exoplanet is discovered!

APOD Viewer Lite: An application that lets you view the astronomy picture of the day. It shows you the image, explanation, and lets you look back at previous images. Very nice app to quickly view today's APOD.

NASA: Basically this is NASA.gov in app form. You can find news,  launch schedules, pictures, videos, telescope info, and anything astronomy you can imagine. Excellent educational app.

ArXiv: This app allows you to search the astrophysics arXiv for scientific papers, and download the pdf to your iphone (using a pdf reader app). This is more for the serious astrophysicists, but anyone can peruse through the papers and maybe you'll find something interesting.

Galaxy Collider Lite: A cute app that shows you what would happen if two galaxies collided. I'm not sure how scientifically accurate the simulations are, but it's cool to watch the galaxies interact regardless. You can set the number of stars, mass of the galaxies, speed of collision, etc. and observe how that changes things

If you've discovered any other cool free apps, post them in the comments section below! Also feel free to leave your opinion about different non-free apps as well!

Exoplanet Update

Artists impression of a "puffy" planet. A comparison to Jupiter is in the bottom right

Exoplanets just fascinate me. The fact that there are potentially millions of other planets and planetary systems in outer space just blows my mind. Planets are being discovered literally on a daily basis. In the past week almost 100 new exoplanets were discovered or confirmed by various telescopes and space agencies. So today I thought I'd talk about a few of the most interesting ones.

Corot-2b: This planet was discovered back in 2007, but a huge discovery about it's interaction with its host star has just been made. The Chandra X-ray observatory just discovered that this planet is being pummeled by X-rays from Corot-2! X-rays are not good for humans, and they are not good for planets either! This roughly 3 Jupiter mass planet is being hit by 100,000 times more X-rays than the earth gets hit with every day. These harmful rays are evaporating the gas that the planet is made of at a rate of 5 million tons per second! Now I know that sounds like a lot, but the planet is so massive that at this rate of evaporation it will still survive for over 30 billion years!

HAT-P 32b, 33b, 24b and others: These are what I like to call "puffy" planets. Puffy planets are half to one Jupiter mass in weight but two Jupiter radii or larger in size and orbit their host star on the order of days. Essentially they are really big, lightweight, fast orbiting planets. They are peculiar because one would expect the planets to be smaller either due to solar wind/X-rays stripping material from them, or just general gravitational collapse of their small amount of gas. Astronomers are currently working on models to describe such planets.

HD 85512-b: This is today's newest possibly habitable planet. HD 85512-b is orbiting a star about 3/4 the size of our sun with an orbital period of 58 days. It's technically too close to the star to be in the habitable zone, but if the planet is rocky, and has sufficient cloud cover, it could potentially be habitable. Much more work needs to be done before we will know if it has the potential to support life.

Image Credit: D. Aguilar

A Planet Made of Diamond!

 Artist's impression of the diamond planet

You read that right! Astronomers believe that they have discovered an exoplanet made of diamond! How can this happen? Well here's the scenario. There was once two stars orbiting each other in a binary system in our galaxy. One star was  bigger than other, and began stealing material from the other smaller star. Over time, the large star stripped so much material off the small star that it couldn't withstand the external pressure and exploded as a supernova! This huge explosion cleared away any gas and star material in the area, leaving behind only the core of the large star (now called a neutron star) and a the core of the small star. Because this is a binary system, the leftover cores began to orbit each other extremely quickly. The angular momentum in the system (speed of rotation, essentially) caused the neutron star to spin on its axis in a fraction of a second (once every 0.0057 seconds to be exact)! We call these stars pulsars, as they emit light from their poles which appears as mili-second pulses in radio telescopes. The small star's core now orbits the pulsar so closely that it only takes two hours for the planet to go around the star! Based on orbital speed and distance to the host star, astronomers speculate that it is less than half the size of Jupiter, but weighs about 1.2 times as much! This high density suggests that the star is made of carbon, and its close proximity to the host star would make it crystallized. And you know what crystallized carbon is… Diamond! A planet 5 times the size of Earth made diamond. I Think I agree with other astronomers who suggest that we somehow find a way to travel to this planet and bring some diamond back! (Though it's quite implausible.) Wouldn't it be awesome to have an exoplanet-diamond ring ? And I thought a meteorite necklace was cool!