Tag Archives: TRAPPIST1

Can Exoplanets Orbiting TRAPPIST-1 and Other Red Dwarfs Support Life?

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A protective atmosphere, a welcoming sun, and abundant liquid water make Earth a remarkable place. Leveraging the extraordinary capabilities of the NASA/ESA/CSA James Webb Space Telescope, astronomers are on a mission to uncover just how unique and extraordinary our planet truly is. Is it possible for a temperate environment to exist elsewhere, perhaps around a different type of star? The TRAPPIST-1 system offers an intriguing opportunity to explore this question, as it contains seven Earth-sized planets orbiting red dwarf stars—the most common type in the Milky Way.

The artist’s concept depicts TRAPPIST-1d passing in front of a turbulent star, showing the other planets in the background. Image credits: NASA/ESA/CSA/Joseph Olmsted, STSCI.

TRAPPIST-1 is a super cool dwarf star situated 38.8 light-years away in the constellation Aquarius.

These stars are slightly larger than Jupiter, comprising only 8% of our Sun’s mass. They rotate quickly and emit UV energy flares.

TRAPPIST-1 is home to seven transiting planets designated TRAPPIST-1b, c, d, e, f, g, and h.

All these planets are similar in size to Earth and Venus, or marginally smaller, with very brief orbital periods of 1.51, 2.42, 4.04, 6.06, 9.21, 12.35, and 20 days, respectively.

They may all be tidally locked, meaning the same side always faces their star, akin to how the same side of the moon is always turned towards Earth. This results in a permanently night side and a permanently day side for each TRAPPIST-1 planet.

“Ultimately, we aim to discover whether similar environments to those we enjoy on Earth exist elsewhere, and under what conditions they might thrive,” stated Dr. Caroline Piaulett Graeb, an astronomer at the University of Chicago and the Trottia Institute for Planetary Research.

“At this stage, we can exclude TRAPPIST-1d as a potential twin or cousin of Earth, even as Webb enables us to investigate Earth-sized planets for the first time.”

Dr. Piaulet-Ghorayeb and her team utilized Webb’s NIRSpec (near-infrared spectroscopy) instrument to capture the transmission spectra of the TRAPPIST-1d planet.

They found no common molecules typically present in Earth’s atmosphere, such as water, methane, or carbon dioxide.

However, they have outlined several possibilities for the exoplanet that warrant further investigation.

“There are multiple reasons we might not detect an atmosphere around TRAPPIST-1d,” Dr. Piaulet-Ghorayeb mentioned.

“It may have a very thin atmosphere, similar to Mars, which is challenging to identify.”

“Alternatively, thick, high-altitude clouds may obscure certain atmospheric signatures.”

“Or it could be a barren rock with no atmosphere whatsoever.”

In any case, TRAPPIST-1d faces challenges as a planet orbiting a red dwarf star.

TRAPPIST-1, the host star of the system, is known for its volatility and often emits high-energy radiation flares that can strip away the atmosphere of nearby small planets.

Nevertheless, scientists remain eager to search for atmospheric signs on the TRAPPIST-1 planets, as red dwarfs are the most prevalent stars in our galaxy.

If these planets can retain an atmosphere here, it suggests they could potentially do so anywhere, even under the harsh conditions of stellar radiation.

“Webb’s sensitive infrared instruments allow us to probe into the atmospheres of these small, cold planets for the first time,” said Dr. Bjorn Beneke, an astronomer at the Institute for Planetary Research at Montreal University.

“We are using Webb to identify atmospheres on Earth-sized planets and define the thresholds between those that can and cannot sustain an atmosphere.”

Results will be published in Astrophysical Journal.

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Caroline Piaulett Graeb et al. 2025. Restrictive conditions on the potential secondary atmosphere of the temperate rocky exoplanet TRAPPIST-1d. APJ 989, 181; doi:10.3847/1538-4357/ADF207

Source: www.sci.news

Allen Telescope Array seeks radio signatures of technology from TRAPPIST-1 system

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The TRAPPIST-1 system is a compact system of at least seven exoplanets that are similar in size to Earth. Astronomers from Pennsylvania State University and the SETI Institute spent 28 hours scanning the system for signs of alien radio technology using the Allen Telescope Array. This project marks the longest single-target search for radio signals from TRAPPIST-1. Although astronomers found no evidence of extraterrestrial technology, their work introduced new ways to search for wireless techno-signatures in the future.

This artist's impression shows a surface view of one of the exoplanets in the TRAPPIST-1 planetary system. Image credit: ESO / M. Kornmesser / Spaceengine.org.

TRAPPIST-1 is an ultracool dwarf star located 38.8 light-years away in the constellation Aquarius.

This star is barely larger than Jupiter and has only 8% the mass of the Sun. It rotates rapidly and produces an energetic flare of ultraviolet light.

TRAPPIST-1 is the home planet of seven transit planets named TRAPPIST-1b, c, d, e, f, g, and h.

All of these planets are the same size or slightly smaller than Earth and Venus, and have very short orbital periods of 1.51, 2.42, 4.04, 6.06, 9.21, 12.35, and 20 days, respectively.

Presumably they are all tidally locked, meaning that the same side of the planet always faces the star, just as the same side of the moon always points towards the Earth. This creates a persistent night side and a persistent day side for each planet in TRAPPIST-1.

Three of the planets, TRAPPIST-1e, f, and g, are located in the star's habitable zone, meaning they may have an environment suitable for life.

“The TRAPPIST-1 system is relatively close to Earth and has detailed information about the planet's orbit, making it an excellent natural laboratory for testing these technologies,” said Penn State graduate student Nick Tasei said.

“The methods and algorithms we developed for this project could eventually be applied to other star systems, increasing the likelihood of finding regular communications between planets beyond our solar system (if they exist). ).

Tusay and his colleagues focused on a phenomenon called interplanetary occultations.

These occultations occur when one planet moves in front of another. If intelligent life exists in that star system, it is possible that radio signals sent between the planets could leak and be detected from Earth.

Astronomers used the upgraded Allen Telescope Array to scan a wide range of frequencies, looking for narrowband signals that could be a possible sign of alien technology.

They filtered through millions of potential signals and narrowed it down to about 11,000 candidates for further analysis.

They detected 2,264 of these signals during the predicted interplanetary occultation period. However, none of the signals were of non-human origin.

New features of the Allen Telescope Array include advanced software to filter signals, helping researchers separate possible alien signals from those on Earth.

They believe that improving these techniques and focusing on phenomena such as interplanetary occultations could increase the chances of detecting alien signals in the future.

Although scientists did not find any alien signals this time, they plan to continue refining their search techniques and exploring other star systems.

Future explorations using larger and more powerful telescopes could help scientists detect even fainter signals and expand our understanding of the universe.

“This study shows that we are getting closer to detecting radio signals similar to those we send into space,” Tusey said.

“Most searches assume some kind of intent, such as a beacon, because our receivers have a sensitivity limit to the minimum transmit power above what we transmit unintentionally.”

“But with better instruments, such as the upcoming Square Kilometer Array, we may soon be able to detect signals from alien civilizations communicating with our spacecraft.”

of the team result will appear in astronomy magazine.

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Nick Tasei others. 2024. TRAPPIST-1 wireless technology signature search using the Allen Telescope Array. A.J.in press. arXiv: 2409.08313

Source: www.sci.news

Research indicates TRAPPIST-1 system developed through a two-stage formation process

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TRAPPIST-1 is an ultracool dwarf star located 38.8 light-years away in the constellation Aquarius that hosts seven planets. The period ratios of the neighboring planets are closer as they move away from the star: 8:5, 5:3, 3:2, 3:2, 4:3, 3:2. This compact resonant configuration is a clear indication of disk-driven migration, but the desired outcome of such an evolution would be the establishment of a first-order resonance, rather than the higher-order resonances observed in the inner system. Astronomer Gabriele Pichierri of the California Institute of Technology and his colleagues explain the orbital configuration of the TRAPPIST-1 system with a model that is largely independent of the specific disk migration and orbital circularization efficiency. Two key elements of the team's model are that, along with the migration, the inner boundary of the protoplanetary disk retreated over time, and that the TRAPPIST-1 system initially separated into two subsystems.

This artist's rendering shows TRAPPIST-1 and its planets as seen on the surface. Image courtesy of NASA / R. Hurt / T. Pyle.

“When all we had to analyse was the solar system, we could simply assume that planets formed where we see them today,” Dr Pichieri said.

“But when the first exoplanet was discovered in 1995, we had to rethink this assumption.”

“We're developing better models of how planets form and how they come to be oriented in the way that we found them.”

Most exoplanets are thought to form from a disk of gas and dust around a newly formed star, and then migrate inwards, approaching the inner boundary of this disk.

This results in a planetary system assembled much closer to the host star than is the case in our solar system.

In the absence of other factors, planets tend to move away from each other at characteristic distances based on their mass and the gravitational force between them and their host star.

“This is the standard transition process,” Dr. Pichieri said.

“The positions of the planets form resonances between their respective orbital periods. If you divide the orbital period of one planet by the orbital period of its neighbor, you get a simple integer ratio like 3:2.”

For example, if one planet takes two days to orbit a star, the next planet further away takes three days.

If the second planet and a more distant third planet were also in 3:2 resonance, the third planet's orbital period would be 4.5 days.

“The exoplanets behave nicely in simpler predicted resonances, so to speak,” Dr Pichieri said.

“But the inner ones have slightly more exciting resonances. For example, the orbital ratio of planets b and c is 8:5, and the ratio of c and d is 5:3.”

“This subtle difference in the outcome of TRAPPIST-1 assembly is puzzling and represents a unique opportunity to tease out in detail what other processes were at work in its assembly.”

“Moreover, most planetary systems are thought to have begun in such resonances, but have experienced significant instabilities during their lifetimes before we observe them today.”

“Most planets would become unstable or collide with each other, and everything would be in chaos. For example, our solar system was affected by such instability.”

“But we know there are some systems that are more or less pristine specimens that have remained stable.”

“They effectively represent a record of its entire dynamical history, and we can try to reconstruct it. TRAPPIST-1 is one of them.”

The challenge then was to develop a model that could explain the orbits of the TRAPPIST-1 planets and how they got to their current configuration.

The resulting model suggests that the inner four planets evolved alone within the originally predicted 3:2 resonant chain.

As the disk's inner boundary expanded outward, the orbits loosened from the tighter 3:2 linkage into the configuration observed today.

The fourth planet was originally located on the inner boundary of the disk and moved outward with the disk, but was pushed back inward at a later stage when three more outer planets joined the planetary system.

“By observing TRAPPIST-1, we were able to test an exciting new hypothesis about the evolution of planetary systems,” said Dr Pichieri.

“TRAPPIST-1 is very interesting because it's a very complex, long chain of planets, and it's a great example for testing alternative theories about the formation of planetary systems.”

of Survey results Published in a journal Natural Astronomy.

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G. Pichieri othersDuring the recession of the inner edge of the disc, the TRAPPIST-1 system forms in two steps. Nat AstronPublished online August 20, 2024, doi: 10.1038/s41550-024-02342-4

Source: www.sci.news