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posted by martyb on Monday August 14 2017, @06:42AM   Printer-friendly
from the my-friends-just-call-me-"2MASS-J23062928-0502285" dept.

TRAPPIST-1 was known to be at least 500 million years old. Now astronomers estimate it to be between 5.4 and 9.8 billion years old:

Scientists now have a good estimate for the age of one of the most intriguing planetary systems discovered to date– TRAPPIST-1, a system of seven Earth-size worlds orbiting an ultra-cool dwarf star about 40 light-years away. Researchers say in a new study that the TRAPPIST-1 star is quite old: between 5.4 and 9.8 billion years. This is up to twice as old as our own solar system, which formed some 4.5 billion years ago.

[...] At the time of its discovery, scientists believed the TRAPPIST-1 system had to be at least 500 million years old, since it takes stars of TRAPPIST-1's low mass (roughly 8 percent that of the Sun) roughly that long to contract to its minimum size, just a bit larger than the planet Jupiter. However, even this lower age limit was uncertain; in theory, the star could be almost as old as the universe itself. Are the orbits of this compact system of planets stable? Might life have enough time to evolve on any of these worlds?

Previously:
Seven Earth-Sized Exoplanets, Including Three Potentially Habitable, Identified Around TRAPPIST-1
TRAPPIST-1h Orbital Details Confirmed


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  • (Score: 0) by Anonymous Coward on Monday August 14 2017, @03:58PM

    by Anonymous Coward on Monday August 14 2017, @03:58PM (#553730)

    I believe the combination of elements changes over time. If you know what kind (size) of star it is, then you can check its element proportion signature using spectragraphs against models which are calibrated using other methods, such as star clusters born at the same time but with different kinds of stars. The metal content may also be a clue: older stars tend to have less metal because each cycle of "nova-ing" produces more metals (including carbon).