Home Radio waves Flashing star stuns with flashes of light

Flashing star stuns with flashes of light

0

Scientists have spotted what appears to be an incredibly dense star that is unlike anything ever seen – and they suspect it could be an exotic *astrophysical* object that hasn’t been known to exist until now. than a theory.

The object, first spotted in the WA outback using the Murchison Widefield Array Telescope, fired huge bursts of energy about three times per hour when viewed from Earth for two months in 2018, researchers said.

This may be the first known example of what is called an “ultra-long-period magnetar*”, they said. These are a variety of neutron stars – the collapsed compact core of a massive star that exploded in a supernova* – that are strongly magnetized and spin relatively slowly, as opposed to rapidly spinning neutron stars called pulsars. which appear to be Earth flashing on and off within milliseconds or seconds.

“It’s incredibly wonderful that the universe is still full of surprises,” said radio astronomer Dr Natasha Hurley-Walker at the Curtin University station of the International Center for Research in Radio Astronomy (ICRAR), lead author of the study. published this week in the journal Nature.

The object can continuously emit strong radio waves from its north and south poles. As this beam swept across the line of sight from Earth’s vantage point*, it seemed to turn on every 18 minutes and 11 seconds for about 30-60 seconds, then turn off again. It’s an effect similar to a lighthouse, with a rotating light that appears to flicker on and off from the perspective* of a stationary observer*.

It was discovered as part of a larger research effort mapping celestial* sources of radio waves.

“This is an entirely new type of source that no one has ever seen before,” Dr. Hurley-Walker said. “And although we know that the Milky Way must be full of slowly rotating neutron stars, no one expected them to be able to produce a bright radio emission like this. It’s a dream come true to find something so totally unexpected and amazing.

It is located relatively close to Earth in cosmic terms, about 4200 light-years away – the distance light travels in a year, or 59.5 trillion kilometers.

“It’s incredibly bright when turned on – it’s one of the brightest radio sources in the sky,” said study co-author Tyrone O’Doherty, PhD student Curtin ICRAR who has found the object.

It falls into a category called “transients” – astrophysical objects that appear to light up for limited durations. “Slow transients” like a supernova can suddenly appear and then disappear a few months later as the stellar explosion dissipates*. Pulsars are “fast transients”, which flash rapidly. The transients between these two extremes had remained elusive* until now.

Neutron stars, including pulsars, are among the densest objects in the universe. They are about 12 km in diameter – equivalent to the size of a city – but with more mass than our sun. A neutron star with an extreme magnetic field, a magnetar, could potentially power the radio pulses, the researchers said.

As for why its rotation is so slow, it could be very old and has slowed down over time, according to astrophysicist Curtin ICRAR and study co-author Dr. Gemma Anderson.

“This is more likely to be first of its kind rather than one of a kind,” Dr. Anderson said.

It could also be another type of dead star called a white dwarf or something completely unknown, according to Dr. Hurley-Walker.

Researchers haven’t detected it since 2018.

“We are now monitoring this object using many different radio telescopes in the hope that it will reignite,” Dr Anderson said.

GLOSSARY

  • exotic: different, exciting, foreign, unknown
  • astrophysics: relating to the branch of physics dealing with astronomical phenomena
  • magnetar: neutron star with a much stronger magnetic field than other neutron stars
  • supernova: star whose luminosity increases considerably after a huge explosion
  • advantage: position, view, point of view
  • perspective: perspective, way of seeing something
  • Stationary: don’t move, still, still
  • celestial: in the sky or space as observed in astronomy
  • dissipates : disappear, vanish, evaporate, dissolve
  • elusive: hard to find, slippery, hard to catch
  • close: similar, akin, close to, comparable

FURTHER READING

Launch of the most powerful space telescope in the world

Mysterious object spied on the moon

A black hole swallows a neutron star

QUICK QUIZ

  1. Where was the object first spotted and with what type of telescope?
  2. The flashing light effect is similar to that created by what type of man-made structure on Earth?
  3. What are transients?
  4. What is the approximate diameter of a neutron in a neutron star?
  5. In what year was the neutron star last detected?

LISTEN TO THIS STORY

CLASS ACTIVITIES
1. Identify key details
This report goes into great detail to explain different facts and theories about the object. Read the article carefully, highlighting only the most important pieces of information. Next, make a point-by-point list of key details that scientists believe to be true about the object.

Time: allow 20 minutes for this activity
Curriculum links: English; Science

2. Extension
What did this news article leave you wondering?

Write down three questions that you hope scientists will find the answer to, related to the subject of this story.

Time: allow 10 minutes for this activity
Curriculum links: English; Science

VCOP ACTIVITY
Grammar and VCOP
The glossary of terms helps you understand and learn the ambitious vocabulary used in the article. Can you use the words shown in the glossary to create new sentences? Challenge yourself to include other VCOP elements (vocabulary, connectors, openings and punctuation) in your sentence(s). Take another look at the article, can you find any other Wow words not described in the glossary?