Tag Archives: Supernova 1987a

Neutron star left over from Supernova 1987A?

The uncertainty of science: Two different teams of astronomers are now suggesting that, based on evidence recently obtained by the Atacama Large Millimeter/submillimeter Array (ALMA), a neutron star is what is left over from the star that caused Supernova 1987A, the only naked eye supernova in the past four hundred years.

Recently, observations from the ALMA radio telescope provided the first indication of the missing neutron star after the explosion. Extremely high-resolution images revealed a hot “blob” in the dusty core of SN 1987A, which is brighter than its surroundings and matches the suspected location of the neutron star.

..The theoretical study by Page and his team, published today in The Astrophysical Journal, strongly supports the suggestion made by the ALMA team that a neutron star is powering the dust blob. “In spite of the supreme complexity of a supernova explosion and the extreme conditions reigning in the interior of a neutron star, the detection of a warm blob of dust is a confirmation of several predictions,” Page explained.

These predictions were the location and the temperature of the neutron star. According to supernova computer models, the explosion has “kicked away” the neutron star from its birthplace with a speed of hundreds of kilometers per second (tens of times faster than the fastest rocket). The blob is exactly at the place where astronomers think the neutron star would be today. And the temperature of the neutron star, which was predicted to be around 5 million degrees Celsius, provides enough energy to explain the brightness of the blob.

They haven’t actually gotten any direct evidence of this stellar remnant, so some healthy skepticism is required. At the same time, the data favors this solution, which means the star did not collapse into a black hole when it exploded.

Astronomers think they have pinned down location of Supernova 1987a’s central star

More than three decades after Supernova 1987a erupted, becoming the first supernova in centuries visible to the naked eye, astronomers finally think they have narrowed the location of the neutron star remaining from that supernova.

Astronomers knew the object must exist but had always struggled to identify its location because of a shroud of obscuring dust. Now, a UK-led team thinks the remnant’s hiding place can be pinpointed from the way it’s been heating up that dust.

The researchers refer to the area of interest as “the blob”. “It’s so much hotter than its surroundings, the blob needs some explanation. It really stands out from its neighbouring dust clumps,” Prof Haley Gomez from Cardiff University told BBC News. “We think it’s being heated by the hot neutron star created in the supernova.”

It will still likely be 50 to 100 years before the dust clears enough for the neutron star itself to be visible.

Timelapse movie of Supernova 1987A’s evolution from 1992 to 2017

Cool movie time! An astronomy graduate student in Toronto has created a movie showing the steady evolution of the shock wave from Supernova 1987A, the first supernova visible to the naked eye since the discovery of the telescope, during the past twenty-five years.

Yvette Cendes, a graduate student with the University of Toronto and the Leiden Observatory, has created a time-lapse showing the aftermath of the supernova over a 25-year period, from 1992 to 2017. The images show the shockwave expanding outward and slamming into debris that ringed the original star before its demise.

In an accompanying paper, published in the Astrophysical Journal on October 31st, Cendes and her colleagues add to the evidence that the expanding remnant is shaped—not like a ring like those of Saturn’s—but like a donut, a form known as a torus. They also confirm that the shockwave has now picked up some one thousand kilometres per second in speed. The acceleration has occurred because the expanding torus has punched through the ring of debris.

The animation, which I have embedded below the fold, uses images produced by an array radio telescopes in Australia.
» Read more