Astronomers discover a quartet of teenage alien planets far, far away

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Astronomers have discovered a quartet of teenage planets, according to data from NASA's TESS telescope.

Astronomers discover a quartet of teenage alien planets far, far away : Read more

 

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The article says, "In the midst of those discoveries lie the planets orbiting TOI 2076. In studying this object, a physics student at Loughborough University in England named Alex Hughes noticed a blip in the data. And when astronomers took a closer look, they found three planets with sizes somewhere between that of Earth and Neptune. TOI 1807, on the other hand, only has one planet, which is around twice Earth's size. This planet orbits its sun at a curiously close distance and astronomers think that a year there could last as little as 13 Earth hours. Planets don't typically form that close to their stars, and the question of how TOI 1807’s planet got there has piqued astronomers' curiosity."

My observation. The interpretation of these exoplanets is interesting. Radii some 2 to 4 earth size, if mean densities like Earth, suggest 8 earth masses for 2 earth radii size. 4 earth radii size, an exoplanet 15 earth masses would have mean density ~ 1.29 g cm^-3. The exoplanets reported receive much more UV energy from their parent stars than Earth does. They all orbit much closer too than Earth does to the Sun. TOI-2076 system is a triple exoplanet system, another solar system. Using the exoplanet sites and MS SQL query selecting orbital periods <=370 days, shows some 3900 or more are reported. Most are large exoplanet masses and sizes so the Earth is not a common type of planet observed among the more than 4,000 exoplanets documented now.

Reference paper, TOI-2076 and TOI-1807: Two Young, Comoving Planetary Systems within 50 pc Identified by TESS that are Ideal Candidates for Further Follow Up, 12-July-2021, https://iopscience.iop.org/article/10.3847/1538-3881/ac06cd.

My observation. Using MS SQL query, more than 1300 exoplanets are documented now with radii <=2 earth size. The average orbital period is 13 days. Most orbit very close to their parent stars too.

The Extrasolar Planets Encyclopaedia (exoplanet.eu), 4796 confirmed exoplanets reported

NASA Exoplanet Archive (caltech.edu), 4434 confirmed exoplanets reported