How far will we go in searching for earth-like planet in the universe? And will we be successful in this? So here we are with not just one but three super-earths found. There has been a new planetary system discovered by astronomers at a distance of 21 light years away. This system named as HD219134, a part of the Cassiopeia constellation includes three inner super earths and massive outer planet, with one transiting in front of the star. The transiting planet has a density that similar to the Earth and is by far the closest transiting super-earth known till date.
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The brilliant planetary system was revealed by the HARPS-N which was designed and built by an international consortium and installed at the Telescopio Nazionale Galileo on the La Palma Island in Spain. According to the researchers, a 5th magnitude K dwarf is slightly cooler and less gigantic compared to our Sun. it is so bright that it can be followed with our naked eyes through dark skies, all year around in our arctic hemisphere
The system revealed that the retinue of planets is made up of three typically rocky super-Earths and an outer giant planet, an arrangement suggestive of our own Solar System. “On the initial indication of the 3-day planet around HD219134, we immediately asked NASA for Spitzer space telescope time”, said Ati Motalebi, astronomer at University of Geneva (UNIGE) and first author of the paper describing the discovery. “The idea was to check for a potential transit of the planet in front of the star, a mini eclipse, that would allow us to measure the size of the planet,”
HD219134b is likely to remain one of the closest transiting planets ever known. This is 4.5 times larger than Earth and 1.6 times bigger. The mass of the planet obtained from the ground based radial velocities, along with the planet radius; yield the mean density of the planet. With a mean density that is close to that of Earth, it suggests a similar composition as well.
The team also discovered three added longer-period planets in the system through the HARPS-N radial velocities. The inner regions host a planet weighing 2.7 times the Earth orbiting HD219134 in 6.8 days, along with a planet of 8.7 times the mass of Earth, residing on a 46.8 day orbit. Any possibility of these two planets being in a coplanar configuration with the third inner sister, by all means, the entire family might be transiting.