Milky Way’s Youngest Pulsar Found 19,000 Light-Years From Earth
Astronomers have managed to locate the youngest pulsar in the Milky Way, NASA announced yesterday. Dubbed PSR J1846-0258, the pulsar was spotted inside one of our galaxy’s supernova remnants — found 19,000 light-years away from our planet, in the Aquila constellation (The Eagle).
This exciting discovery — first detailed in a study published earlier this year in The Astrophysical Journal — could shed more light into supernova explosions and the new beginnings that arise from the death of a stellar giant.
What Are Pulsars And How Do They Form?
When massive stars reach the end of their life cycle, they go out in a big way. As they run out of fuel, their core collapses and they explode into a supernova, leaving behind a rich material chock-full of chemical elements.
The resulting structure is known as a supernova remnant — a floating mass of leftover debris, the Inquisitr previously reported, that eventually goes on to form something new entirely.
Compressed by gravity, the protons and electrons of these dead stars melt into neutrons, giving birth to neutron stars — city-sized stellar objects packing more mass than the sun.
According to Space, neutron stars have a mass about 1.4 times that of the sun, crammed within a tight space measuring around 12.4 miles (20 kilometers) across.
Highly-magnetized, fast-spinning neutron stars are called pulsars — named so due to their incredibly fast rotation, which makes them appear like light pulses in the sky when observed from Earth.
Emerged from the ashes of exploded stars, these stellar “phoenixes” were first discovered in the 1960s, the Inquisitr recently reported. Since then, astronomers have found more than 2,000 pulsars — with the youngest one in the galaxy now being confirmed.
Youngest Pulsar In The Milky Way
Our galaxy’s youngest pulsar was detected inside a supernova remnant that goes by the name of Kes 75. The pulsar is roughly 500-years-old and was spotted with the help of NASA’s Chandra X-Ray Observatory.
After studying Kes 75 over a period of 16 years — in 2000, 2006, 2009, and 2016 — Chandra uncovered the pulsar nestling within the supernova remnant by picking up its X-ray emissions. The Chandra observations revealed that the superdense star is wrapped by a pulsar wind nebula (PWN) — a magnetized bubble of high-energy particles floating inside the supernova remnant.
“We confirm directly that Kes 75 contains the youngest known PWN, and hence youngest known pulsar,” the study authors wrote in their paper.
A stunning photo of the pulsar was unveiled yesterday by NASA, along with a news release detailing how the object was found.
This brightly-colored remnant is Kes 75, a star 🌟until it exploded in a supernova 💥, 500 years ago. Astronomers used data from @ChandraXRay to confirm that it contains the youngest known pulsar in our Milky Way galaxy. Read about the star's demise: https://t.co/ikAsDTEOIJ pic.twitter.com/wg3Zh7JTja
— NASA (@NASA) October 18, 2018
The photo represents a composite image created from data gathered in 2006 and 2016, details the Chandra X-Ray Observatory website.
“In this composite image of Kes 75, high-energy X-rays observed by Chandra are colored blue and highlight the pulsar wind nebula surrounding the pulsar, while lower-energy X-rays appear purple and show the debris from the explosion,” explained NASA officials.
“The rapid rotation and strong magnetic field of the pulsar have generated a wind of energetic matter and antimatter particles that flow away from the pulsar at near the speed of light.”
The remarkable thing about this pulsar wind nebula is that it’s continuously growing — expanding at a whopping 1 million meters per second, or over 2 million miles per hour. At the same time, its brightness waned by 10 percent between 2009 and 2016, particularly in its northern region — with one of the bright knots inside the PWN growing 30 percent dimmer since 2006.
These rapid changes puzzled the astronomers, who ventured an explanation for the unusual features of the pulsar.
“We suggest that the PWN is expanding into an asymmetric nickel bubble in a conventional Type IIP supernova,” the researchers wrote in the study, showing that the supernova explosion filled the bubble both with radioactive nickel and iron gas.
“Chandra data also give insight into the very heart of the exploded star and the chemical elements it created,” observatory officials wrote yesterday on Twitter.
While the newfound pulsar was formed relatively recently, there are no records of the celestial event that sparked its creation, as no one on Earth saw it happen at the time.
Unlike in other, more famous cases — such as that of the much closer Eta Carinae double star, detailed in a previous Inquisitr article — the explosion that created Kes 75 and PSR J1846-0258 didn’t light up the sky over our planet. As NASA points out, the dense interstellar gas and dust floating in that part of the Milky Way “would have rendered it too dim to be seen from Earth several centuries ago.”