In the far future, the universe will be mostly invisible

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If you look out on the sky on a nice clear dark night, you’ll see thousands of intense points of light. Those stars are incredibly far away, but bright enough to be seen with the naked eye from that great distance – a considerable feat. But what you don’t see are all the small stars, the red dwarfs, too small and dim to be seen at those same distances.

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How Did the TRAPPIST-1 Planets Get Their Water?

Most exoplanets orbit red dwarf stars because they're the most plentiful stars. This is an artist's illustration of what the TRAPPIST-1 system might look like from a vantage point near planet TRAPPIST-1f (at right). Credits: NASA/JPL-Caltech

In 2017, an international team of astronomers announced a momentous discovery. Based on years of observations, they found that the TRAPPIST-1 system (an M-type red dwarf located 40 light-years from Earth) contained no less than seven rocky planets! Equally exciting was the fact that three of these planets were found within the star’s Habitable Zone (HZ), and that the system itself has had 8 billion years to develop the chemistry for life.

At the same time, the fact that these planets orbit tightly around a red dwarf star has given rise to doubts that these three planets could maintain an atmosphere or liquid water for very long. According to new research by an international team of astronomers, it all comes down to the composition of the debris disk that the planets formed from and whether or not comets were around to distribute water afterward.

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Giant Planets Could Form Around Tiny Stars in Just a Few Thousand Years

M-type (red dwarf) stars are cooler, low-mass, low-luminosity objects that make up the vast majority of stars in our Universe – accounting for 85% of stars in the Milky Way galaxy alone. In recent years, these stars have proven to be a treasure trove for exoplanet hunters, with multiple terrestrial (aka. Earth-like) planets confirmed around the Solar System’s nearest red dwarfs.

But what is even more surprising is the fact that some red dwarfs have been found to have planets that are comparable in size and mass to Jupiter orbiting them. A new study conducted by a team of researchers from the University of Central Lancashire (UCLan) has addressed the mystery of how this could be happening. In essence, their work shows that gas giants only take a few thousand years to form.

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Without a Magnetosphere, Planets Orbiting Flare Stars Don’t Stand a Chance

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Earthlings are fortunate. Our planet has a robust magnetic shield. Without out magnetosphere, the Sun’s radiation would’ve probably ended life on Earth before it even got going. And our Sun is rather tame, in stellar terms.

What’s it like for exoplanets orbiting more active stars?

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The Planet-Hunting TESS Discovers Its Smallest Exoplanet to Date

Thanks in large part to the Kepler Space Telescope, the number of confirmed extrasolar planets has grown exponentially in the last decade. And with next-generation missions like the Transiting Exoplanet Survey Satellite (TESS) already in orbit, more candidates and confirmed planets are being discovered all the time – many of them new and exciting ones too!

In fact, one of TESS’ most recent discoveries includes a three-planet system that orbits a star (L 98-59) located roughly 35 light-years from Earth. One of the planets, known as L 98-59b, is between the sizes of Earth and Mars – effectively making it the smallest exoplanet discovered by TESS to date. The discovery also highlights the sophistication of TESS and doubles the number of small exoplanets that are considered worthy of follow-up studies.

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Two Earth-Like Worlds Found Orbiting a Red Dwarf Only 12.5 Light-Years Away

In the past few decades, there has been an explosion in the number of planets discovered beyond our Solar System. With over 4,000 confirmed exoplanets to date, the process has gradually shifted from discovery towards characterization. This consists of using refined techniques to determine just how likely a planet is to be habitable.

At the same time, astronomers continue to make discoveries regularly, some of which are right in our cosmic backyard. For instance, an international team of researchers recently detected two new Earth-like planets orbiting Teegarden’s Star, an M-type (red dwarf) star located just 12.5 light-years from the Solar System in the direction of the Aries constellation.

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Bad News. Planets Orbiting Red Dwarfs Might not have the Raw Materials for Life

New research from the Hubble Space Telescope and the ESO’s Very Large Telescope is dampening some of the enthusiasm in the search for life. Observations by both ‘scopes suggest that the raw materials necessary for life may be rare in solar systems centered around red dwarfs.

And if the raw materials aren’t there, it may mean that many of the exoplanets we’ve found in the habitable zones of other stars just aren’t habitable after-all.

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Super Earth Planet Found Around One of the Closest Stars to us. But it’s Probably a Terrible Place to Live

In the course of searching for extra-solar planets, some very interesting finds have been made. Some of them have even occurred within our own galactic neighborhood. Just two years ago, astronomers from the Red Dots and CARMENES campaigns announced the discovery of Proxima b, a rocky planet that orbits within the habitable zone of our nearest stellar neighbor – Proxima Centauri.

This rocky world, which may be habitable, remains the closest exoplanet ever discovered to our Solar System. A few days ago (on Nov. 14th), Red Dots and CARMENES announced another find: a rocky planet orbiting Barnard’s star, which is just 6 light years from Earth. This planet, Barnard’s Star b, is now the second closest exoplanet to our Solar System, and the closest planet to orbit a single star.

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The Closest Planet Ever Discovered Outside the Solar System Could be Habitable With a Dayside Ocean

In of August of 2016, astronomers from the European Southern Observatory (ESO) confirmed the existence of an Earth-like planet around Proxima Centauri – the closest star to our Solar System. In addition, they confirmed that this planet (Proxima b) orbited within its star’s habitable zone. Since that time, multiple studies have been conducted to determine if Proxima b could in fact be habitable.

Unfortunately, most of this research has not been very encouraging. For instance, many studies have indicated that Proxima b’s sun experiences too much flare activity for the planet to sustain an atmosphere and liquid water on its surface.  However, in a new NASA-led study, a team of scientists has investigated various climate scenarios that indicate that Proxima b could still have enough water to support life.

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