New planet appears that may have life like Earth

A research team led by astronomer Xavier Dumusque from the University of Geneva (Switzerland) announced that they have identified three new planets orbiting an "unusual" star called HD 20794.

One of the three new planets, HD 20794d, could be a rocky planet similar to Earth and located right in the star's "habitable zone."

 

Super-Earth HD 20794d could be a habitable planet - Graphic image: NASA

According to Sci-News, HD 20794 is a bright G6V-type star located 19.7 light-years away in the constellation Eridanus.

Also known as LHS 19 or e Eri, this star hosts at least three giant exoplanets: HD 20794b, HD 20794c, and HD 20794d.

These three planets have orbital periods of 18.3, 89.7, and 647.6 days, and masses of 2.2, 3, and 5.8 times the mass of Earth, respectively.

Among them, super-Earth HD 20794d is of most interest because calculations show that it is located in the "habitable zone" of its parent star, the area that ensures the existence of liquid water, like Earth, Venus and Mars in the Solar System.

 

There's one slight difference: Instead of following a relatively circular orbit like Earth or Mars, HD 20794d follows an elliptical orbit, meaning the distance between the planet and its star changes greatly as it rotates.

The planet thus oscillates between the inner edge of the "habitable zone" and the outer edge of it in its orbit.

This leads to extreme changes between seasons, but according to scientists it was beneficial in helping life arise.

'If there is water on HD 20794d, the water will change from ice to liquid state, favorable for life to appear' - Dr. Dumusque affirmed.

More specifically, the "unusual" thing about this planet's parent star that scientists mentioned is its surprisingly good brightness and closeness.

Coupled with the large size of the surrounding planets, observing them is extremely convenient compared to other known exoplanets.

"The HD 20794 system is a high-priority target for future atmospheric characterization by direct imaging means," the authors wrote in a paper published in the scientific journal Astronomy & Astrophysics.