The internet is abuzz with the recent discovery of Trappist-1, but the discoveries of the future shouldn't outshine the discoveries of the past. 30 years ago, one of the brightest exploding stars was discovered on February 23, 1987. Since we've now hit the anniversary of this milestone, NASA has been releasing new images and information about one of the most spectacular stellar events ever witnessed.
Thirty years later, and we're still learning about the explosion. According to NASA, “The latest data from these powerful telescopes indicate that SN 1987A has passed an important threshold. The supernova shock wave is moving beyond the dense ring of gas produced late in the life of the pre-supernova star when a fast outflow or wind from the star collided with a slower wind generated in an earlier red giant phase of the star's evolution.”
Supernova 1987A (aka the titanic supernova) sits 160,000 light-years from Earth in the Large Magellanic Cloud, a satellite galaxy of our home galaxy, the Milky Way. The close proximity of the exploding star has given astronomers a better look at each phase of the death of a star.
"Because of its early detection and relative proximity to Earth, SN 1987A has become the best studied supernova ever. Prior to SN 1987A, our knowledge of supernovae was simplistic and idealized. But by studying the evolution of SN 1987A from supernova to supernova remnant in superb detail, using telescopes in space and on the ground, astronomers have gained revolutionary insights into the deaths of massive stars," said a statement issued by the European Space Agency (ESA).
Supernova 1987A exploded with the power of over 100 million suns for several months after it was discovered in 1987. The force of the explosion made Supernova 1987A one of the brightest supernovas witnessed in over 400 years.
Astronomers have discovered that the gas and remnant star material was actually ejected from the dying star 20,000 years before the explosion took place. This material was then carried away from Supernova 1987A by slow-moving stellar winds.
However, as the star continued to die, it turned into a hot body and the stellar winds increased speed, causing slower material to pile up. This caused concentric ring-like structures to form around the supernova, which were then observed by astronomers here on Earth.
"The initial burst of light from the supernova illuminated the rings. They slowly faded over the first decade after the explosion, until the shock wave of the supernova slammed into the inner ring in 2001, heating the gas to searing temperatures and generating strong X-ray emission," said the ESA. Pretty cool, huh?
Today, Supernova 1987A is an expanding cloud of gas and stardust, but scientists are still keeping an eye on it. Supernova 1987A was studied in great detail by the Hubble Space Telescope after the telescope was launched into space in 1990. "Hubble was the first to see the event in high resolution," said the ESA. "Hubble's observations of this process shed light on how supernovae can affect the dynamics and chemistry of their surrounding environment, and thus shape galactic evolution."
But the observation of Supernova 1987A has not been limited to the Hubble Telescope. For the past three decades, Supernova 1987A has become the most studied supernova. NASA'sChandra X-ray telescope has been observing the supernova since the launch of the telescope in 1999, and the European Southern Observatory’s Atacama Large Millimeter/submillimeter Array (ALMA) is also keeping an eye on it.
The ring around Supernova 1987A has begun to fade in recent years. “From about February 2013 until the last Chandra observation analyzed in September 2015 the total amount of low-energy X-rays has remained constant,” NASA said. “These changes provide evidence that the explosion's blast wave has moved beyond the ring into a region with less dense gas. This represents the end of an era for SN 1987A.”
The supernova's 30th "birthday" is going to be celebrated in ways most 30 year olds would dream of. Salvatore Orlando at INAF-Osservatorio Astronomico di Palermo, Italy has released new animation, time-lapse movies, images and a 3D model of the supernova to commemorate the 30th anniversary of the discovery of Supernova 1987A.
NASA is also celebrating the 30th anniversary of the supernova and has uploaded some pretty cool videos of Supernova 1987A on their website, and they're worth a watch. "Astronomers — and the public — can explore SN 1987A like never before," says NASA of the videos.