Showing posts with label Radio Waves. Show all posts
Showing posts with label Radio Waves. Show all posts

Friday, April 7

Radio Signals From Space


(CNN) -- Astronomers have detected a repeating radio signal from an exoplanet and the star that it orbits, both located 12 light-years away from Earth. The signal suggests that the Earth-size planet may have a magnetic field and perhaps even an atmosphere.

Earth’s magnetic field protects the planet’s atmosphere, which life needs to survive, by deflecting energetic particles and plasma that stream out from the sun. Finding atmospheres around planets located outside of our solar system could point to other worlds that potentially have the ability to support life.

Scientists noticed strong radio waves coming from the star YZ Ceti and the rocky exoplanet that orbits it, called YZ Ceti b, during observations using the Karl G. Jansky Very Large Array of telescopes in New Mexico. The researchers believe the radio signal was created by interactions between the planet’s magnetic field and the star.

A study detailing the findings was published Monday in the journal Nature Astronomy.“We saw the initial burst and it looked beautiful,” said lead study author Sebastian Pineda, a research astrophysicist at the University of Colorado Boulder, in a statement. “When we saw it again, it was very indicative that, OK, maybe we really have something here.”

Magnetic fields can prevent a planet’s atmosphere from being diminished and essentially eroded away over time as particles release from the star and bombard it, Pineda said.

How strong radio waves occur
In order for the radio waves to be detectable on Earth, they must be very strong, the researchers said.  “Whether a planet survives with an atmosphere or not can depend on whether the planet has a strong magnetic field or not,” Pineda said.

Previously, researchers have detected magnetic fields on exoplanets similar in size to Jupiter, the largest planet in our solar system. But finding magnetic fields on smaller planets the size of Earth is more difficult because magnetic fields are essentially invisible.“What we’re doing is looking for a way to see them,” said study coauthor Jackie Villadsen, assistant professor of physics and astronomy at Bucknell University in Pennsylvania, in a statement.

“We’re looking for planets that are really close to their stars and are a similar size to Earth,” she said. “These planets are way too close to their stars to be somewhere you could live, but because they are so close the planet is kind of plowing through a bunch of stuff coming off the star. If the planet has a magnetic field and it plows through enough star stuff, it will cause the star to emit bright radio waves.”

YZ Ceti b only takes two Earth days to complete a single orbit around its star. Meanwhile, the shortest orbit in our solar system is the planet Mercury, which takes 88 Earth days to complete a lap around the sun.  READ MORE...

Wednesday, January 26

Radio Signals From Milky Way

The radio telescope at the Parkes Observatory at sunset near the town of Parkes, Australia, July 15, 2019.  Stefica Nicol Bikes/Reuters



Mysterious radio waves emanating from the center of the galaxy have astronomers stumped.
Four objects have briefly emitted radio signals that don't resemble any known type of star.
Scientists think each of the four signals could come from a new type of object unknown to astronomy.

Ziteng Wang found a needle in an astronomical haystack.

Wang, a physics PhD student at the University of Sydney, was combing through data from Australia's ASKAP radio telescope in late 2020. His research team had detected 2 million objects with the telescope and was classifying each one.

The computer identified most of the stars, and the stage of life or death they were in. It picked out telltale signs of a pulsar (a rapidly rotating dead star), for example, or a supernova explosion. But one object in the center of our galaxy stumped the computer and the researchers.

The object emitted powerful radio waves throughout 2020 — six signals over nine months. Its irregular pattern and polarized radio emissions didn't look like anything the researchers had seen before.

Even stranger, they couldn't find the object in X-ray, visible, or infrared light. They lost the radio signal, too, despite listening for months with two different radio telescopes.

It reappeared suddenly, about a year after they first detected it, but within a day, it was gone again.  READ MORE...