Astronomers have discovered seven Earth-like exo- planets orbiting the same star, 40 light years away from Earth. The findings were revealed through a study that was published on 22 February in a journal called Nature and through a news conference, held at the NASA headquarters in Washington.
- The seven planets have been found to be in a tight circle around a star called TRAPPIST-1, which is almost one tenth the size of the sun and about a quarter as warm.
- The seven of them are distanced at a space five times smaller than the distance between Mercury and our sun.
- While the planet closest to the star takes about just one and half days to orbit around it, the farthest one is reported to take about 20 days.
- Despite such proximity to the sun-like star, these planets are not unbearably warm.
- Estimates of their mass indicate that they are all rocky planets.
- Three of the seven planets-TRAPPIST-1e, f and g fall in the habitable zone, leading to the possibility of them having water on their surface.
- While the first three planets according to the researchers would be too warm to support liquid water, the farthest one would be too cool.
According to researchers, TRAPPIST-1f looks to be the best candidate for supporting life. It is a bit cooler than Earth but it may have the right atmosphere and though TRAPPIST-1 is a dwarf star, it would appear three times as big as the sun when looked upon from TRAPPIST-1f.
- The discovery was made by a team led by Michaël Gillon of the Université de Liège.
- Generally, ultracool dwarf stars like TRAPPIST-1 are very common in the galaxy and so, are largely overlooked.
- Gillon however, decided to study the space around one of these dwarf stars.
- The researchers used a telescope called TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) to observe its space.
- He noticed dimness at certain intervals in the star’s light.
- Further observation helped them see shadows, little eclipses that interrupted the steady pattern of the starlight periodically.
- The shadows indicated planets, and further observation confirmed it.
- Earlier they saw just three planets and slowly later they discovered all seven and were able to determine their orbital periods, distances from their star, masses and their radius.