Astronomers observe the aurora borealis on Uranus for the first time

“astronomer” reveal “twilight” In the infrared wave range “Uranus” I got it for the first time after almost 40 years of trying

Date: November 7, 2023 Facebook Nareit National Institute for Astronomical Research He posted a message stating: Astronomers have discovered the aurora borealis in the infrared spectrum of Uranus for the first time. After nearly 40 years of effort, the discovery was made using data from a giant ground-based telescope called Keck II located on Mauna Kea. Hawaiian Islands, USA, and this research was published in the academic journal Nature Astronomy on October 23, 2023, led by Emma Thomas.

The Keck II telescope is a high quality telescope. It was installed at the highest point of Mauna Kea volcano in the Hawaiian Islands. The United States Keck telescopes are dual telescopes Keck I and Keck II, each of which has a primary mirror with a diameter of about 10 meters, and the primary mirror consists of 36 small hexagonal mirrors that can be grouped together. Therefore the images are of high quality.

The aurora borealis (aurora borealis) occurs when charged particles come from the solar wind. It interacts with the planet’s magnetic field and moves along the magnetic field lines toward the magnetic poles. When entering the planet’s atmosphere, charged particles collide with particles in the atmosphere. As a result, these particles glow. It creates beautiful colored light above the planet’s atmosphere.

The birth of the aurora borealis on Earth results from the collision of charged particles from the solar wind with oxygen and nitrogen atoms. Until the light becomes red, green and blue, it can be seen in areas near the North and South Poles. As for the aurora that occurs on Uranus, it is not directly visible to the human eye as it is on our planet. Because it consists of hydrogen and helium molecules in an atmosphere much lower than Earth’s temperature. When they are stimulated by charged particles from the solar wind, energy is released at ultraviolet and infrared wavelengths.

The aurora on Uranus is in the ultraviolet wavelengths and was first seen in 1986 by NASA’s Voyager 2 spacecraft, which flew by the planet that year. It will take approximately another 40 years before we can say that at infrared wavelengths we can also see the aurora.

The discovery was made on September 5, 2006 by Emma Thomas, a graduate student at the University of Leicester, England, using data from the Keck II Near-Infrared Spectrograph, or NIRSPEC, observing celestial objects at near-infrared wavelengths. Studies on Uranus have found spectral lines from a “trihydrogen cation” or H3+, a molecule of hydrogen gas that decays into a positively charged 3 protons and 2 electrons.

The solar wind collides with the atmosphere of Uranus. This will cause hydrogen gas to decompose into ions. It then forms H3+ molecules and releases energy in the form of infrared radiation. It occurs near the north pole of the star. This can be said to be the “Northern Lights” on Uranus.

Astronomers found that the measured temperatures of Uranus and all the gas giant planets were all about a hundred degrees Celsius higher than in the model. This is unlikely to be a result of the sun’s heat alone. One possible hypothesis is that the high-energy aurora that occurs may be the origin of thermal energy spreading from the magnetic poles. The magnetic field moved toward the equator. As a result, the planet’s temperature became higher than the model calculated.

Normally, the axis of a planet’s magnetic field will have an orientation that corresponds to its axis of rotation. But for Uranus and Neptune, the magnetic axis is tilted from its axis of rotation by 59 degrees and 47 degrees, respectively, so the study of the aurora is related to the direction of the magnetic field. It may help astronomers find new evidence. About the magnetic field distortions that could occur on these two gas planets.

Thank you Facebook NARIT, National Institute for Astronomical Research.