Those who hunt the night skies in search of worlds beyond our own have had much to hang their laurels on in the past 30 years. From the first confirmation of planets orbiting a star other than our own back in 1992, exoplanet hunting has become a huge deal, with more than 4,000 confirmed to be orbiting more than 3,000 stars so far.
But it’s one thing to know those planets are there – the one thing we haven’t really been able to do is see them.
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To find exoplanets, astronomers rely on indirect observations.
Basically, astronomers look for things like patterns in how light from stars will dim as planets pass between them and Earth. From that and other observations, they can calculate things like a planet’s size, the distance from its sun, and possibly whether it’s rocky, like Earth or Mars, or gaseous like Jupiter or Saturn.
But while all these indirect observations do yield all kinds of wonderful data, it’s not quite the same as seeing . Now, we’re starting to actually see some of those other worlds directly.
What’s more, we’ve now gotten an image of two planets orbiting a star like our own sun.
Astronomers using the European Southern Observatory’s Very Large Telescope got the image of the planets orbiting a star about 300 light years away in the constellation of Musca.
And while the star in question might be like our sun, it and its solar system are different in some startling ways.
For one, the star is much, much younger than our own.
At just 17 million years old, it’s a virtual baby compared with our sun, which is about 4.6 billion years old.
The other big difference is the planets themselves: they’re gas giants like Jupiter and Saturn, but much further away from their star. They orbit at 160 and 320 times the distance of the Earth to the Sun respectively, whereas Jupiter and Saturn orbit the Sun at five and 10 times the Earth-Sun distance.
The planets are also huge.
The inner planet is about 14 times the size of Jupiter, which is by far the largest planet in our solar system. The outer planet is also larger than Jupiter, but only by about six times.
There may be other, smaller planets orbiting the star as well, but so far that’s unknown.
However, the astronomers hope to be able to use coming technology like the ESO Extremely Large Telescope and the James Webb Space telescope to get a better look at this new solar system.
“The possibility that future instruments, such as those available on the ELT (Extremely Large Telescope), will be able to detect even lower-mass planets around this star marks an important milestone in understanding multi-planet systems, with potential implications for the history of our own Solar System,” said the study’s lead author, Alexander Bohn of Leiden University in The Netherlands in a press release .
So, this first-ever image of two planets orbiting a sun-like star appears to be the start of something exciting.
“Even though astronomers have indirectly detected thousands of planets in our galaxy, only a tiny fraction of these exoplanets have been directly imaged,” said co-author Matthew Kenworthy, “direct observations are important in the search for environments that can support life.”
The image and the research accompanying it were published in The Astrophysical Journal Letters .
h/t: EurekAlert
