Red dwarf stars are the most common kind of star in our neighbourhood, and probably in the Milky Way. Because of that, many of the Earth-like and potentially life-supporting exoplanets we’ve detected are in orbit around red dwarfs. The problem is that red dwarfs can exhibit intense flaring behaviour, much more energetic than our relatively placid Sun.
So what does that mean for the potential of those exoplanets to actually support life?
“This is where we live. On a Blue Dot.” said Carl Sagan when the now famous Pale Blue Dot photo was released. Captured February 14, 1990 by the Voyager 1 Space Probe, Pale Blue Dot remains the most distant photograph of the Earth ever taken at 6 billion kilometers. This past February marked the 30th anniversary of Pale Blue Dot which was reprocessed using modern digital photo techniques creating an even more remarkable image.
Whether Pale Blue Dot, or Blue Marble, our planet is associated with the color blue. As Earth is the only inhabited world we know of, it might stand to reason that other habitable planets in space will also be blue. But it’s a little more complicated than that.
REMINDER: – Universe Today will be hosting an interview with Dr. Dirk Schulze-Makuch, co-author of the research featured in this article, on Thursday October 15th, 2020 at 8:30am PT. Click the video below to watch live or to see the recorded stream afterward
Out Earthing Earth
What planet is this?
If you said Hoth, that’s a good guess. But, it’s actually Earth depicted in one of two known “snowball” states. The entire planet’s surface was locked beneath glacial ice during the Cryogenian Period 650 million years ago and during the Huronian Glaciation 2 – 2.4 billion years ago.
Star’s can be full of surprises; some of them nasty. While our own Sun appears pretty placid, science has shown us that’s not the case. Coronal mass ejections and solar flares are the Sun’s angry side.
And the Sun has only a mild case of the flares, compared to some other stars.
Scientists are getting better at understanding exoplanets. We now know that they’re plentiful, and that they can even orbit dead white dwarf stars. Researchers are also getting better at understanding how they form, and what they’re made of.
A new study says that some carbon-rich exoplanets could be made of silica, and even diamonds, under the right circumstances.
We’re getting better and better at detecting exoplanets. Using the transit method of detection, the Kepler Space Telescope examined over 530,000 stars and discovered over 2,600 explanets in nine years. TESS, the successor to Kepler, is still active, and has so far identified over 1800 candidate exoplanets, with 46 confirmed.
But what if, hidden in all that data, there were even more planets? Astronomers at Warwick University said they’ve found one of these “lost” planets, and that they think they’ll find even more.
Sunspots are common on our Sun. These darker patches are cooler than their surroundings, and they’re caused by spikes in magnetic flux that inhibit convection. Without convection, those areas cool and darken.
Lots of other stars have sunspots, too. But Red Giants (RGs) don’t. Or so astronomers thought.
A new study shows that some RGs do have spots, and that they rotate faster than thought.
Our closest stellar neighbour is Proxima Centauri, a small red dwarf star about 4.2 light years away from us. It’s the third member of the Alpha Centauri group, and even though it’s so close, it can’t be seen with the naked eye. In 2016 astronomers discovered a planet orbiting Proxima Centuari, named Proxima Centauri b. That planet was confirmed only a few days ago.
Now, astronomers have confirmed the existence of a second planet, Proxima Centauri c.