These Newly-Discovered Planets are Doomed

Three more exoplanets have been found. The discovery might not last long. Each planet is in a separate solar system and is very close to its star. All of the stars are dying.

The results?

Three planets are doomed.

Thousands of exoplanets have been found in the last few years and decades. There are Earth-like planets in their stars' quiet zones to planets so hot that iron falls as rain.

There is something in common between these three exoplanets. They have very short periods around sub-giant or giant stars. The writing is on the wall for planets like these, which will spiral inward towards their stars.

A team of researchers presented these grim findings in a new paper. The paper was accepted by the journal and is on the website arxiv.org. The lead author is Samuel Grunblatt. He is a researcher at the American Museum of Natural History.

Three doomed planets that will spiral inwards toward their end, with stars that are also inching towards death, are the discovery. That would be misrepresenting the discovery. Think of it as planetary archaeology.

These discoveries are important to understanding a new frontier in exoplanet studies, how planetary systems evolve over time. New windows into planets nearing the end of their lives are offered by these observations.

The planets are TOI-2337b, TOI-4329b, and TOI-2669b. The number is the star and it is called TOI. The planet closest to the star is referred to as the b.

The figure shows what TESS data can look like after it is processed. The panels were processed differently, but they all show the same result. The researchers used data from three different sources to strengthen their results after a nearby star contaminated the stellar flux data. The data was gathered over three days. The image was created by Grunblatt et al.

Jupiter is similar to all of the planets in our Solar System. They were found during a survey looking for new planets. The worlds range from small to large in size. The stars range in size from 1.2 to 1.5 solar mass and from 2.3 to 4.1 solar radii.

Each of the solar systems underwent a chaotic period of planet-to-planet interactions according to the densities of the planets. Astronomers think that the history of those interactions contributed to the density variations.

Some of the details in at least one of these systems may be teased out by the James Webb Space Telescope. The TOI-4329 system has water and CO2 in the atmosphere, which could affect the location of the planet. It could give insight into the types of planetary interactions that put the planet into its current position.

Scientists can use the data from the James Webb Space Telescope to analyze the materials that make up stars, nebulae, galaxies, and planets. The image is from the European Space Agency.

Astronomers expect the planets to inflate as they get closer to the stars. The planets will eventually be engulfed by the stars. TESS hasn't found any evidence of a decaying orbit so far. During its Prime Mission, TESS found these planets. During its extended missions, it will gather more data and form a longer baseline of observations. The longer baseline may show that the planets are already in their death spirals.

The metric of planetary inflation is being used more and more. Why do some planets have larger radii than others? Gas giants experience cooling from their inner depths, which slows inflation over time. It is possible that proximity to a star will delay that cooling.

There is growing evidence that stars can cause inflation. The authors wrote in a previous paper that stellar irradiation could explain the current size of the planets.

Scientists think that gas giants like Jupiter have a deep radiative zone that transfers heat to a convective zone. The planet is kept from inflating by the release of heat. Inflation can be caused by the heat from the star being added to the planet. The image is from NASA and JPL-Caltech.

There is a complicated issue of planetary inflation. The authors of the paper wrote that the planet may be inflated by methods that are more strongly dependent on atmospheric metallicity than incident flux.

There is evidence of inflation for at least one planet. The shortest orbital period around a red giant star has been found by TOI-2337b, but it shows no sign of inflation. The TOI-2669b system is the most evolved of the three, yet the planet doesn't show any signs of inflation. There are signs of inflation in TOI-4329b.

The other two targets are not as bright as TOI-2669b. It's a good target for the telescope. New constraints on planet inflation and migration mechanisms could be placed by that data.

There are more planets in this study. TESS should find more of them. The TESS system will provide new details on how planets interact with each other, inflate and migrate around stars, including those like our Sun.

TESS had some help. The transit method only revealed candidate exoplanets. Follow-up observations are required for confirmation as exoplanets. The HIRES instrument was provided by the Keck Observatory. The discoveries were made with data from HIRES.

The twin Kecks prepare for observing as the sun sets. Laurie Hatch is the astronomer at the W. M. Keck Observatory.

The fate of solar systems like our own is revealed by the Keck observations of planetary systems. This study might be small steps towards answering the most important question of our time: Are we alone?

All of this may sound academic to a casual reader. One day our own Sun will leave the main sequence and begin to expand into a red subgiant, which will likely cause Earth to be engulfed. It is doubtful that humanity will survive until then since it will not happen for billions of years. The norm on Earth is extinctions, but maybe humanity will beat the odds.

We are learning more about nature and the Universe.

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