قالب وردپرس درنا توس
Home / Science / Astronomers report first observations of a & # 39; Circumplanetary Disk & # 39; – Science Daily

Astronomers report first observations of a & # 39; Circumplanetary Disk & # 39; – Science Daily



Using the Earth's most powerful radio telescopes, astronomers have made the first observations of a surrounding disk of gas and dust, which is believed to have produced the moons of Jupiter.

The Astrophysical Journal Letters published online today, completes the fascinating history of the planet PDS 70 c, a still-forming gas giant that is about 370 light-years from Earth and was first launched in the last month Images with visible light was revealed.

Atacama Large Millimeter / Submillimeter Array (ALMA) with 66 antennas in Chile, the astronomer of Rice University, Andrea Isella, and colleagues collected millimeter-wave signals indicating the presence of dust grains throughout the star system of PDS 70 c and its sister planet PDS 70 b showed, are still forming.

"Planets are formed by gas and dust around newly formed stars, and if a planet is large enough, it can form its own disk if it collects material in its orbit around the star," said Isella. "Jupiter and its moons, for example, are a small planetary system in our solar system, and it is believed that Jupiter's moons were created from a perimeter disk when Jupiter was very young."

However, most models of planet formation show that radius orbital disks disappear into them for about 1

0 million years, which means that there are no longer circums planetary disks in our solar system for more than 4 billion years. In search of her elsewhere and collecting observational evidence to test planet formation theories, Isella and colleagues are looking for very young star systems where they can directly observe disks and the planets still forming within them. In the new study, Isella and colleagues analyzed the observations made by ALMA in 2017.

"There are a handful of candidate planets discovered on discs, but this is a very new field and they are all still being debated." Isella said. "(PDS 70 b and PDS 70 c) are among the most robust since independent observations were performed using different tools and techniques."

PDS 70 is a dwarf star that is about three quarters of the Sun's mass. Both planets are five to ten times larger than Jupiter, and the innermost, PDS 70 b, orbits the star at a distance of about 1.8 billion miles, which is roughly the distance between the Sun and Uranus. PDS 70 c is one billion miles further in orbit about the size of Neptune.

PDS 70 b was first discovered in 2018 in infrared light images of a planetary hunt instrument called SPHERE at the Very Large Telescope of the European Southern Observatory (VLT). In June, astronomers used another VLT instrument called MUSE to observe a visible wavelength of light, known as H-alpha, emitted when hydrogen falls on a star or planet and becomes ionized.

"H-alpha gives us more security These are planets because it suggests they are still attracting and growing gas and dust," said Isella.

ALMA's millimeter-wavelength observations provide even more evidence.

"They complement the optical data and provide a completely independent confirmation that there is something there," he said.

Isella said that direct observation of planets with circumplanetary disks could allow astronomers to test theories about planet formation.

"There is much that we do not understand, how planets are formed, and now we finally have the tools to make direct observations and answer questions about how our solar system has formed and how other planets could form.

Isella is an assistant professor of physics and astronomy, as well as earth, environmental, and planetary sciences at Rice and co-investigator of the NASA-funded Rice CLEVER Planets project.

Story Source:

Materials provided by Rice University . Original written by Jade Boyd. Note: Content can be edited by style and length.


Source link