Space and astronomy news
In September 2022, an automated sky survey detected what seemed to be a supernova explosion about one billion light-years away. The Zwicky Transient Facility (ZTF) spotted it and gave it the name AT2022tsd. But something was different about this supernova. Supernovae explode and shine brightly for months, while AT2022tsd exploded brightly and then faded within days.
Continue reading “Can a Dead Star Keep Exploding?”
Measuring cosmic distances is challenging, and astronomers rely on multiple methods and tools to do it – collectively referred to as the Cosmic Distance Ladder. One particularly crucial tool is Type Ia supernovae, which occur in binary systems where one star (a white dwarf) consumes matter from a companion (often a red giant) until it reaches the Chandrasekhar Limit and collapses under its own mass. As these stars blow off their outer layers in a massive explosion, they temporarily outshine everything in the background.
In a recent study, an international team of researchers led by Ariel Goobar of the Oskar Klein Centre at Stockholm University discovered an unusual Type Ia supernova, SN Zwicky (SN 2022qmx). In an unusual twist, the team observed an “Einstein Cross,” an unusual phenomenon predicted by Einstein’s Theory of General Relativity where the presence of a gravitational lens in the foreground amplifies light from a distant object. This was a major accomplishment for the team since it involved observing two very rare astronomical events that happened to coincide.
Continue reading “Astronomers See the Same Supernova Four Times Thanks to a Gravitational Lens”
Throughout recorded history, humans have looked up at the night sky and witnessed the major astronomical events known as a “supernova.” The name, still used by astronomers, referred to the belief that these bursts of light in the “firmament” signaled the birth of a “new star.” With the birth of telescopes and modern astronomy, we have since learned that supernovae are what occur at the end of a star’s lifecycle. At this point, when a star has exhausted its hydrogen and helium fuel, it experiences gravitational collapse at its center.
This leads to a tremendous explosion that can be seen billions of light-years distant, releasing tremendous amounts of energy and blowing the star’s outer layers off. Thanks to an international team of astronomers led by the University of Southhampton, the most powerful cosmic explosion has been confirmed! The stellar explosion, AT2021lwx, took place about 8 billion light-years away in the constellation Vulpecula and was over ten times brighter than any supernova ever observed and 100 times brighter than all the stars in the Milky Way combined!
Continue reading “The Largest Explosion Ever Seen in the Universe”
With the rapid expansion of commercial space, there is a growing number of satellites in orbit around our planet. Most of these are in low-Earth orbit, which is becoming increasingly crowded. This has led some to be concerned about a catastrophic rise of space debris, as well as a growing frustration by astronomers due to the number of satellite sky trails.
Continue reading “20% of Twilight Observations Contain Satellite Passes”
Astronomers have painstakingly built models of the asteroid population, and those models predict that there will be ~1 km sized asteroids that orbit closer to the Sun than Venus does. The problem is, nobody’s been able to find one. Until now.
Astronomers working with the Zwicky Transient Facility say they’ve finally found one. But this one’s bigger, at about 2 km. If its existence can be confirmed, then asteroid population models may have to be updated.
Continue reading “Astronomers Have Discovered a 2-km Asteroid Orbiting Closer to the Sun than Venus”
Astronomers at Caltech’s Zwicky Transient Facility (ZTF) have discovered an asteroid that orbits inside Venus. Though other asteroids have a portion of their orbit inside Venus’, this is the first one with an orbit that is completely inside Venus’ orbit. The new object is named 2020 AV2.
Continue reading “An Asteroid has been Found that Orbits the Sun Closer than Venus”