Astronomers have spotted a mysteriously gargantuan explosion a hundred times more massive than an exploding star and they have no idea what it is.
More than a dozen telescopes from all over the world have recorded the inexplicable event, which was first seen on June 16 in the skies above Hawaii.
Early speculations point to a giant cloud of high-speed particles moving at a rate of 12,000 miles per second and registering a temperature of 16,000 degrees Fahrenheit. However, everything is a wild guess at this point.
No Idea What It Is
Nicknamed "The Cow," the explosion was first spotted using the ATLAS telescope at the Keck Observatory in Mauna Kea, Hi. Scientists believe that the object is located just 200 million light-years from Earth, which is quite near by astronomical standards.
The light coming from the object is unusually bright. Astronomers estimate it to be 10 to 100 times more luminous than a regular supernova, which can generate more light and energy in a flash than the Sun can in its entire lifetime.
Scientists have hailed supernovas the most powerful explosions that can take place in space. The Cow apparently eclipses that.
To add fuel to the perplexing fire, observers have noted that the explosion happened over an exceptionally short amount of time. Usually, it takes a few weeks for a cosmic explosion to reach its brightest point. However, this time the explosion climaxed in two days before the brightness began to dwindle.
"It really just appeared out of nowhere," says Kate Maguire, an astronomer at Queen's University Belfast and a member of the team that mans ATLAS. "There are other objects that have been discovered that are as fast, but the fastness and the brightness, that's quite unusual."
"I've never seen anything like this before in the local universe," adds astrophysicist Stephen Smartt, also part of the ATLAS team.
Following the initial observation in Hawaii, numerous reports have been sent to Astronomer's Telegram, a website for astronomers around the world to send reports of interesting finds. The website's automatic naming system has given it the name AT2018cow, hence the nickname The Cow.
At least 18 telescopes across four continents are said to have been trained on the mysterious object. Robert Rutledge, Editor-in-Chief of Astronomer's Telegram and astrophysicist at Canada's McGill University, says AT2018cow received the biggest number of reports for a single astronomical object over the span of a few days.
Some experts initially suggested that the explosion could have happened within the Milky Way because of its unusual luminosity. It is remarkably bright across all spectrums, including visible light, X-ray, and electromagnetic.
However, a spectroscopic analysis done by astronomers in China reveals that the explosion took place in a galaxy called CGCG 137-068 in the constellation Hercules. The light signature on the object shows it took 200 million light years for the light from the explosion to reach observers on Earth.
It is also possible that the object generated gravitational waves, ripples in the fabric of space-time caused by extremely powerful events. Supernovas are a prime candidate for detecting gravitational waves. Unfortunately, the LIGO detectors are down for maintenance so there is no knowing if AT2018cow produced gravitational waves.
Could It Be A Rare Breed Of Supernova?
When a star explodes in its last hurrah, the explosion is marred by special features called spectral lines, which are light signatures given off at a certain frequency by a specific atom. The object in question does not have spectral lines.
A possible explanation, although untested, is that it could be a Type 1c supernova, a less common type of supernova where a massive star stripped of its outer layer of helium and hydrogen gases collapses to its core. The powerful X-ray and electromagnetic waves also indicate that it could have produced a stream of particles moving at the speed of light.
"This does look like it is quite a rare object," Smartt says. "Just the fact that it's detected over all these wavelengths leaves a lot of rich physics to understand."