Astronomers used NASA’s Chandra X-ray Observatory to detect X-rays from Uranus, revealing the previously unknown scale of this majestic ice giant.
new Find, Published in “JGR: Physics”, which means that X-ray emission has been detected on every planet in the solar system Except for Neptune. More importantly, this discovery may yield new insights into X-ray emitting objects further away, including black holes, supernovae, quasars and neutron stars. This new paper is led by William Dunn, an astronomer at University College London.
Uranus is mainly composed of hydrogen and helium, and has two rings in its orbit above the equator. The planet rotates on its side relative to the plane of the solar system, so it looks a bit like an odd ball (no other planet can do this). In 1986, NASA’s Voyager 2 spacecraft visited Uranus very briefly, so astronomers have been relying on telescopes such as Chandra and Hubble to study the seventh planet of the sun.
Dunn, physicist Affelia Wibisono, University College London (UCL) PhD, and co-author of the study found evidence of X-ray emission from Uranus in Chandra data collected in 2002 and 2017. The 2002 data was collected by Chandra Advanced CCD imaging spectrometer, And the 2017 data comes from Chandra’s High resolution camera, In addition to optical observation. The observed signals are very weak, but they are there.
After confirming the X-rays on Uranus, the challenge now is to determine the cause.
“There are three main ways planets produce X-rays: fluorescence, the scattering of solar X-rays, and auroral radiation,” Wibisono explained. article She writes for the Chandra website.
Uranus, like many other objects in the solar system, including comets, moons, and even the dwarf planet Pluto, can scatter X-rays received by the sun. But this does not seem to be the only source of X-rays from Uranus. As Wibisono pointed out, “Our calculations show that Uranus produces more X-rays than the X-rays produced by the Earth simply scattering the X-rays of the sun.”
The author proposes two different theories to explain emissions.One possibility is that Uranus’ rings are churning X-rays, which is similar to what happened. The ring around Saturn. This process occurs when high-energy charged particles (such as electrons and protons) collide with the ring and emit light in X-rays, known as fluorescence.
Another possibility is that X-rays are produced by Uranus’ aurora, as explained in an article by NASA. statement.
On Earth, we can see colorful lights called “Aurora” in the sky, which occur when high-energy particles interact with the atmosphere. X-rays are emitted in the aurora of the earth and are generated by high-energy electrons after they travel along the planet’s magnetic field lines to their poles and are decelerated by the atmosphere. Jupiter also has aurora. X-rays from the aurora on Jupiter come from two sources: electrons travel along magnetic field lines (as on Earth), and positively charged atoms and molecules rain in Jupiter’s polar regions.
The trouble is, people still know very little about the cause of the aurora on Uranus, so most of them are still speculation. Wibisono admitted: “Further “it needs Chandra and other X-ray telescopes to observe Uranus before we can give a clear answer.”
Uranus is a fascinating object for studying all aspects of distant planets due to its unusual spin axis and irregular magnetic field. With its strange tilt, astronomers can see Uranus at irregular angles, and because its magnetic field is also strangely tilted, astronomers can finally find a connection with the planet’s complex and variable aurora. There is still a lot to learn about this strange and wonderful ice giant.