Tatooine planet. What is that? Those of you who have interest in our universe already know that there are solar systems with two suns. These are called twin stars. There is one in our vicinity. You must have heard of the Cygnus constellation. That is where sits a two-star system. Now, planets that orbit around such two-star or double-star or twin-star systems are known as Tatooine planets.
The name Tatooine is a colloquial term used quite often. This term comes from Star Wars franchise. Officially, such planets are known as Circumbinary Planets. This new Tatooine planet is catalogued as Kepler-1647b because it was discovered by Kepler Space Telescope of NASA.
About Tatooine Planet Kepler-1647b
Kepler-1647b is the largest planet that has been discovered that orbits the two-star system. The planet has been discovered by astronomers at San Diego State University, California and Goddard Space Flight Center in Maryland. Sitting approximately at a distance of 3,700 light years from our planet Earth, this Tatooine planet is about the size of our Jupiter. Interestingly, just like Jupiter, Kepler-1647b is also a gas giant.
Talking of the stars that it orbits, one of the stars of the twin-star system is slightly smaller than our very own Sun. The other star is slightly larger than our Sun. Scientists at NASA say that the planet is definitely not a hospitable place but its moon might present suitable conditions for habitation.
This newly discovered planet has radius and mass that is almost identical to Jupiter. This makes the Kepler-1647b the largest Circumbinary Planet to have been discovered so far. Scientists also say that the planet is roughly the same age as our Earth. It is speculated to be 4.4 billion years old.
Also, this newly discovered Tatooine planet has an orbit period of 1,107 days. That is the longest orbiting period for a transiting exoplanet that has been discovered so far.
There is another odd thing about Kepler-1647b. Usually Circumbinary Planets are known to be in orbits that are close to their host star. This is not the case with this largest Tatooine planet. It is way farther from host stars than speculated. Because of this distance, the planet actually sits in the habitable-zone.
Habitable zone is the distance of an exoplanet from its host star where there is possibility of liquid water being present on the planet’s surface. Of course, Kepler-1647b rules that out because it is a gas giant but its moons, that are pretty big may actually be able to host life.
The Largest Tatooine Planet Took Too Long to Be Discovered
One of the most surprising facts about this largest-so-far Tatooine planet is that it took quite some time to be discovered. The interesting fact is that the spotting of the planet by Kepler Space Telescope took place 5 years ago. The confirmation came late because it took time to calculate (of course with the help of computers) and determine that it was actually a Tatooine or a Circumbinary Planet.
Why this problem? The reason is simple but we need to dig in deep for a proper explanation. See, the Kepler Space Telescope does one thing –
It looks for transits. What is that? When a planet passes in front of a star, it blocks the light of the star relative to the telescope (that is orbiting our Earth) observing it. This phenomenon is known as transit. The Kepler Telescope looks straight at stars. Of course, it keeps getting uniform amount of star light. When a planet moves between the star and the telescope, there is a dip in star light. This means a transit happened.
In case of our Tatooine planet Kepler-1647b, the planet is actually orbiting two different stars. This gives rise to irregular patterns or even long and complex patterns that are repetitive by nature. Analyzing such patterns is really difficult. This explains why so much time was required to determine that it was indeed a Circumbinary planet. To make things worse, Kepler-1647b has a long orbiting period and hence, the telescope had to wait really long to get enough data.
Is Kepler-1647b the Only Tatooine Planet?
No it isn’t. 11 more have been discovered earlier and all of them were discovered by Kepler Space Telescope. Those 11 Circumbinary Planets are either the size of Saturn or smaller. Scientists believe that there are there are millions of such Tatooine planets in our very own Milky Way Galaxy. There will be more outside of our galaxy.
For long humans have been fascinated by the prospect of a planet orbiting two stars. Practical proof started coming only a few years back. Will we find more Tatooine planets in future? Only time will tell.