It is possible that astronomers using a new technique have not only found a super-Earth at a neighboring star, but they have also imagined it directly. And it could be beautiful and comfortable in the living area around Alpha Centauri.
It is much easier to see giant planets than planets the size of Earth. Regardless of the detection method used, larger planets are simply a larger needle in the cosmic hay. But in general, astronomers are very interested in Earth-like planets. And finding them is much more difficult.
We thought we’d have to wait for the ultra-powerful telescopes to be built now before we could directly imagine the exoplanets.
Facilities such as the Magellan Giant Telescope and the European Extremely Large Telescope will bring enormous observational power to the exoplanet image.
But a team of researchers has developed a new technique that could do the job. They say they imagined a possible sub-Neptune / super-Earth planet, orbiting one of our closest neighbors, Alpha Centauri A.
The team presented its observations in an article from Communications about nature entitled “Imagination of low-mass planets in the habitable zone of α Centauri”. The lead author is Kevin Wagner, an astronomer and Sagan Fellow at the University of Arizona.
While astronomers have found low-mass exoplanets, they have never felt their light. They watched the planets reveal themselves by pulling out their stars. And they saw the light of the stars that host these planets dim when the planet passes in front of the star.
But they never imagined directly. So far, maybe.
This new detection method is reduced to infrared. One of the challenges in imaging infrared-sized exoplanets of the Earth is to discern the light that comes from an exoplanet when that light is washed away by all the background infrared radiation on the star.
Astronomers can look for exoplanets at wavelengths where the background infrared is diminished, but at the same wavelengths, temperate, Earth-like planets are weak.
One method is to look at the near infrared (NIR) side of the spectrum. In NIR, the thermal brightness of the planet is not so washed away by the star. But starlight is still dazzling and millions of times brighter than the planet. So just searching the NIR is not a total solution.
The solution may be the NEAR (New Earths in the AlphaCen Region) tool used in this research. NEAR is mounted on the very large telescope (VLT) ESO (Southern European Observatory) in Chile. Works with the VISIR tool, also on VLT. The group behind NEAR is Breakthrough Watch, part of Yuri Milner’s Breakthrough Initiatives.
The NEAR instrument not only observes in the desired part of the infrared spectrum, but also uses a coronary.
The Breakthrough Group believed that the NEAR instrument used on an 8-meter terrestrial telescope would allow better observations of the Alpha Centauri system and its planets.
So, they built the instrument in collaboration with ESO and installed it on the very large Telescope.
This new discovery came as a result of 100 hours of cumulative observations with NEAR and VLT.
“These results,” the authors write, “demonstrate the feasibility of imaging rocky exoplanets in habitable areas with current and future telescopes.”
Commissioning for 100 hours was intended to demonstrate the power of the instrument.
The team says that based on about 80 percent of the best images in that run, the NEAR instrument is an order of magnitude better than other methods of observing “… warm sub-Neptune planets along many habitable areas of α Centauri A. “
They also found a planet. “Are we also talking about a possible detection of the exoplanet or the exosodial disk around? Centaurs A “, they write. “However, an instrumental artifact of unknown origin cannot be ruled out.”
This is not the first time astronomers have found exoplanets in the Alpha Centauri system.
There are several confirmed planets in the system and there are other candidates.
But none of them was directly imagined as this potential new planet, which is called the C1 substituent and is the first potential detection around the dwarf M in the system, Proxima Centauri.
Subsequent observations will have to confirm or cancel the discovery.
It is exciting to think that a warm Neptune-class exoplanet could orbit a Sun-like star in the nearest neighboring star system. One of the goals of the Breakthrough initiative is to send spaceships with light sails to the Alpha Centauri system and take a closer look.
But this perspective is not yet reached. And in some ways, this discovery is not so much about the planet as it is about the technology developed to detect it.
The vast majority of discovered exoplanets are giant planets similar in mass to Jupiter, Saturn and Neptune. They are the easiest to find. But as humans on Earth, we are primarily interested in planets like ours.
Earth-like planets in the habitable zone of a star make us excited about life prospects on another planet. But they can also tell us a lot about our own solar system and how solar systems form and evolve in general.
If C1 turns out to be a planet, then the Breakthrough group has succeeded in a vital effort. They are the first to detect an Earth-like planet through direct imaging.
Not only that, but they did it with an 8-meter telescope, on the ground and with a tool specially designed and developed to detect these types of planets in the Alpha Centauri system.
The authors are confident that NEAR can work well, even compared to much larger telescopes. The conclusion of the paper contains a description of the general sensitivity of the instrument. Then they write that “This would be in principle enough to detect an analog planet of Earth around α Centauri A (~ 20 µJy) in just a few hours, which is in line with expectations for ELTs. ”
The E-ELT will have a 39-meter primary mirror. One of its capabilities and design goals is to imagine exoplanets, especially the smallest, the size of Earth, directly.
Of course, the E-ELT will be an extremely powerful telescope that will undoubtedly fuel scientific discovery for a long time, not only in the imaging of the exoplanet, but in a variety of other ways.
Other giant ground-based telescopes will also change the game of exoplanet images.
What took hours to see nearby may take just a few minutes for the E-ELT, the Thirty-Meter Telescope, or the Magellan Giant Telescope to be seen.
NEAR cannot compete with those telescopes and was never meant to do that.
But if these results are confirmed, then NEAR has succeeded where no one else and for a fraction of the price of a new telescope.
In any case, what NEAR has accomplished is probably the future of exoplanet research. Rather than extensive surveys, such as Kepler and TESS, scientists will soon be able to focus on individual planets.
This article was originally published by Universe Today. Read the original article.