"If rocky planets exist around white dwarfs, we could detect signs of life on them in the next few years," said lead author Lisa Keltenger, associate professor of astronomy in the College of Arts and Sciences and director of the Carl Sagan Institute.
When stars like our Sun die, all that is left is a bare core - a white dwarf. A planet orbiting a white dwarf offers a promising opportunity to determine whether life can survive the death of its star, according to Cornell researchers.
In a study published on September 16, 2020 in the Astrophysical Journal Letters, they show how NASA's soon-to-be-launched James Webb Space Telescope could find signatures of life in Earth-like planets orbiting white dwarfs.
A planet orbiting a small star produces strong atmospheric signals as it passes in front of its host star. White dwarfs take this to the extreme: they are a hundred times smaller than our Sun, almost as small as Earth, and allow astronomers a rare opportunity to characterize rocky planets.
"If rocky planets exist around white dwarfs, we will be able to detect signs of life on them in the coming years," said co-author Lisa Keltenger, associate professor of astronomy in the College of Arts and Sciences and director of the Carl Sagan Institute.
Co-lead author Ryan McDonald, a researcher at the institute, said NASA's James Webb Space Telescope, scheduled for launch in October 2021, is uniquely positioned to find signatures of life on rocky extrasolar planets.
"When observing Earth-like planets orbiting white dwarfs, the James Webb Space Telescope can detect water and carbon dioxide within hours," McDonald said. "An observation time of two days using this powerful telescope will allow the discovery of biological signature gases, such as ozone and methane."
The discovery of the first giant planet to transit a white dwarf it orbits (WD 1856+534b), announced on September 16 in a separate paper — lead author Andrew Vanderburgh, a senior lecturer at the University of Wisconsin, Madison — proves the existence of stars Walk around white dwarfs. Keltenger is a co-author of this article as well.
This planet is a gas giant and therefore incapable of sustaining life. But its existence suggests that smaller rocky planets, which can support life, can also exist in the habitable regions of white dwarfs.
In a newly published study, Cornell researchers show how NASA's soon-to-be-launched James Webb Space Telescope could find signatures of life in Earth-like planets orbiting stars that have run out of burning fuel, called white dwarfs.
"We now know that giant planets can exist around white dwarfs, and evidence dating back more than a century shows rocky material contaminating light from white dwarfs. There are certainly small rocks in white dwarf systems," said MacDonald. "It's a logical leap to imagine a rocky Earth-like planet orbiting a white dwarf."
The study combined cutting-edge analysis techniques routinely used to detect gases in the atmospheres of giant exoplanets using the Hubble Space Telescope with models of white dwarf planet atmospheres from previous Cornell research.
The Transiting Extrasolar Planet Survey satellite is now looking for such rocky planets around white dwarfs. And if and when one of these worlds is found, Keltenger and her team developed the models and tools to detect signs of life in the planet's atmosphere. The Webb Telescope will soon be able to begin this search.
The implications of finding signatures of life on a planet orbiting a white dwarf are far-reaching, Keltenger said. More stars, including our Sun, will one day become white dwarfs.
"What if the death of a star is not the end of life?" she said. “Can life continue, even after our sun dies? Signs of life on planets orbiting white dwarfs will show not only the incredible tenacity of life, but perhaps also a glimpse into our future."
More of the topic in Hayadan:
2 תגובות
When will the James Watt Space Telescope finally be launched?
The "Webb" space telescope is an extraterrestrial in itself. I suggested to myself to abstain from his future fantasies/plans/achievements - until I see him standing at the L2 point. Too many delays, too many deficiencies, too many complexities in features, launch and placement there. am waiting.