Astronomers making use of the Atacama Large Millimeter/submillimeter Array (ALMA) have discovered new proof that a pretty young neutron star is hiding deep inside the remains of the supernova 1987A (SN 1987A).
This artist’s illustration of SN 1987A shows the dusty inner regions of the exploded star’s remnants (red), in which a neutron star may possibly be hiding. This inner area is contrasted with the outer shell (blue), exactly where the power from the supernova is colliding (green) with the envelope of gas ejected from the star prior to its strong detonation. Image credit: NRAO / AUI / NSF / B. Saxton.
SN 1987A is a stellar explosion that occurred from a star about 20 instances the mass of the Sun.
This supernova was initial observed on February 23, 1987 in a nearby dwarf galaxy, the Large Magellanic Cloud, some 164,000 light-years away.
It was the initial naked-eye supernova to be observed because Johannes Kepler witnessed a supernova more than 400 years ago.
Ever because astronomers witnessed SN 1987A, they have been browsing for a compact object that ought to have formed in the leftovers from the blast.
Because particles recognized as neutrinos have been detected on Earth on the day of the explosion, they anticipated that a neutron star had formed in the collapsed center of the star.
But when they could not locate any proof for that star, they began to wonder irrespective of whether it subsequently collapsed into a black hole alternatively.
Recently, observations from the ALMA radio telescope supplied the initial indication of the missing neutron star soon after the explosion.
Extremely higher-resolution photos revealed a hot blob in the dusty core of SN 1987A, which is brighter than its surroundings and matches the suspected place of the neutron star.
“We were very surprised to see this warm blob made by a thick cloud of dust in the supernova remnant,” mentioned Dr. Mikako Matsuura, an astronomer at Cardiff University.
“There has to be something in the cloud that has heated up the dust and which makes it shine. That’s why we suggested that there is a neutron star hiding inside the dust cloud.”
“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,” mentioned Dr. Dany Page, an astrophysicist at the National Autonomous University of Mexico.
Extremely higher-resolution ALMA photos revealed a hot blob in the dusty core of SN 1987A (inset), which could be the place of the missing neutron star. The red colour shows dust and cold gas in the center of the supernova remnant, taken at radio wavelengths with ALMA. The green and blue hues reveal exactly where the expanding shock wave from the exploded star is colliding with a ring of material about the supernova. The green represents the glow of visible light, captured by the NASA/ESA Hubble Space Telescope. The blue colour reveals the hottest gas and is primarily based on information from NASA’s Chandra X-ray Observatory. The ring was initially created to glow by the flash of light from the original explosion. Over subsequent years the ring material has brightened significantly as the explosion’s shock wave slams into it. Image credit: ALMA / ESO / NAOJ / NRAO / P. Cigan / R. Indebetouw / AUI / NSF / B. Saxton / NASA / ESA / Hubble / Chandra.
According to supernova laptop models, SN 1987A kicked away the neutron star from its birthplace with a speed of hundreds of km per second.
The blob is specifically at the spot exactly where astronomers assume the neutron star would be nowadays.
And the temperature of the neutron star, which was predicted to be about five million degrees Celsius, offers adequate power to clarify the brightness of the blob.
“The neutron star behaves exactly like we expected,” mentioned Dr. James Lattimer, an astronomer at Stony Brook University.
“The supernova’s neutrino signal suggested that a black hole never formed, and moreover it seems difficult for a black hole to explain the observed brightness of the blob. We compared all possibilities and concluded that a hot neutron star is the most likely explanation.”
According to the group, the neutron star is a 25-km (15.five-mile) wide hot ball of ultra-dense matter.
Because it can only be 33 years old, it would be the youngest neutron star ever discovered.
The second-youngest recognized neutron star is positioned in the supernova remnant Cassiopeia A and is 330 years old.
Only a direct image of the neutron star would give definite proof that it exists, but for that astronomers could have to have to wait a couple of additional decades till the dust and gas in the supernova remnant turn out to be additional transparent.
The findings have been published in two papers in the Astrophysical Journal.
Dany Page et al. 2020. NS 1987A in SN 1987A. ApJ 898, 125 doi: 10.3847/1538-4357/ab93c2
Phil Cigan et al. 2020. High Angular Resolution ALMA Images of Dust and Molecules in the SN 1987A Ejecta. ApJ 886, 51 doi: 10.3847/1538-4357/ab4b46