‘Formation of planets’ revealed by new space discovery

Pablo Tucker
July 30, 2019

The space telescope uses an array of wide-field cameras to perform a survey of 85 percent of the sky. The three known planets were discovered by NASA's Transiting Exoplanet Survey Satellite through periodic dips in starlight caused by each orbiting world.

"TESS, pictured in this artists" impression, was launched on April 18 a year ago and can observe nearly the entire sky. The initial TESS data was supplemented by multi-wavelength photometry, spectroscopy, and high-resolution digital imagery collected by ground-based telescopes.

"In addition to finding a diverse set of exoplanets, TESS has discovered a treasure trove of astrophysical phenomena, including thousands of violently variable stellar objects".

The trio of newfound worlds orbit around an M-dwarf star that has already experienced its youthful energetic phase, and now shines with a steady light.

Within the system known as TOI-270 there is a rocky super-Earth that is slightly larger than our own planet, as well as two gaseous sub-Neptunes, roughly twice Earth's size.

The planet closest to the star is about 25% bigger than Earth and is likely rocky. Instead, our solar system is occupied by two extremes - the smaller rocky planets such as Mercury and Venus, and the enormous gassy giants Jupiter, Saturn and Neptune.

The discovery, published in Nature Astronomy, also has researchers curious about a type of "missing link" planet we don't have in our own solar system.

The study's lead author added: "You can really do all the things you want to do in exoplanet science with this system". The star and its planet could provide valuable information on how planetary bodies form.

The researchers believe there there is a good chance that more planets might lie further out in the star system - some of which might potentially lie the star's habitable zone.

TOI-270-d most likely has a thick atmosphere which produces an intense greenhouse effect, causing the planet's surface to be too hot for habitation.

TOI 270 d and c are around 2.4 and 2.1 times larger than Earth, orbiting the star every 5.7 and 11.4 days respectively.

The three planets appear to be in "resonance" with each other, meaning the ratios of their orbital periods are close to whole numbers.

Periodically, as the exoplanets move through their orbits, they line up with each other relative to their star, and their gravitational forces influence, or resonate with one another.

Compare and contrast worlds in the TOI 270 system with these illustrations of each planet.

'That's a very interesting thing, because it lets us study their dynamical behaviour'.

The newly-discovered planets have been described by astrophysicist Maximilian Günther of the Massachusetts Institute of Technology - which helped to develop TESS - and his colleagues.

Other reports by iNewsToday