Hi, Jasmine here. I'm this year's summer programs assistant. This week, I'm excited to share with you what I think are some of the most fascinating objects in the universe - neutron stars.

Neutron stars start their lives with a bang! When a star that is much more massive than our Sun runs out of fuel at the end of its life, its core collapses and its outer layers are blown off into space in a spectacular explosion called a supernova. What the star becomes next depends on how much mass it started with. The most massive stars become black holes while slightly less massive stars become neutron stars. But don’t let the neutron star’s more well-known cousin, the black hole, capture all of your attention! Neutron stars are fantastically bizarre objects in their own right.
 
A typical neutron star has a radius of about 10 kilometers and is roughly 1.4 times as heavy as our Sun. That’s as heavy as half a million Earths! Imagine squeezing all that mass into an area that’s barely the size of Vancouver. What you end up with is some incredibly dense matter – a teaspoon of the stuff is as heavy as Mount Everest, Earth’s tallest mountain.

Of course, if you actually wanted to collect a teaspoon of neutron star matter, you might run into some trouble. As you approach a neutron star, you would get caught in its super strong gravitational field and be pulled to its surface so fast that even the atoms that make up your body would be ripped apart. If you somehow survived your descent, the million-degree surface temperatures would immediately vaporize you. But don’t feel too gloomy. Even if you were able to survive on the surface of a neutron star, the crust is estimated to be 10 billion times stronger than steel, so you’d probably have a hard time scooping it up with a normal teaspoon anyway.

Luckily scientists who study neutron stars don’t have to visit them – they listen for them. That’s how Dame Jocelyn Bell Burnell first discovered pulsars, a type of neutron star, in 1967 when she was a doctoral student at the University of Cambridge. She noticed a strange, repeating radio signal coming from an area of the sky in the constellation Vulpecula. Bell Burnell and her advisor Antony Hewish jokingly named it LGM-1, for “little green men”, but Bell Burnell quickly ruled out aliens when she saw a similar signal coming from another part of the sky.











Image Credit: Wikimedia Commons

A pulsar spews out a steady beam of light from each its magnetic poles. Like a cosmic lighthouse, these beams sweep across the universe, swinging in and out of our view as the pulsar spins. To astronomers on Earth, it looks like a signal that is blinking on and off. Different pulsars spin at different speeds. The fastest spinning pulsar, discovered by Jason W. T. Hessels of McGill University, rotates 716 times per second. Even high-speed blenders don’t spin that fast! In case you were wondering, the Vitamix 5200 blender only rotates a measly 475 times per second.
 
Magnetars are another type of neutron star. Most neutron stars have magnetic fields trillions of times stronger than Earth’s, but magnetars have magnetic fields that are another 1000 times stronger. If you were on Earth, a magnetar would be able to pull your keys out of your pocket from as far away as the Moon! These intense magnetic fields can cause starquakes, rupturing the magnetar’s surface and releasing powerful blasts of gamma rays that can affect Earth’s upper atmosphere despite being thousands of light-years away.












An artist’s impression of magnetar SGR1935+2154  
Image Credit: ESA

Magnetars might be the key to the solving the mystery of the millisecond-long radio blips astronomers detect all over our sky. Up until recently, these fast radio bursts (FRBs) have always come from distant galaxies but in late April, a magnetar named SGR1935+2154 in our galaxy unleashed a burst of high-energy radio waves that scientists think look like an FRB. This discovery suggests that magnetars may be the source of some FRBs, but what’s puzzling is that the burst was less energetic than fast radio bursts seen in distant galaxies. The magnetar hypothesis also has trouble explaining why some FRBs appear to repeat.

There is still a lot that we don’t understand about neutron stars, but what I think is one of the best things about the universe is that there’s so much out there just waiting to be discovered. Check out the playlists to learn more about these extreme and enigmatic objects.

Junior Astronomer Playlist (kids 8-12)
TimeActivity
30mins.

Be a space detective and figure out who – or what – is behind the exploding stars that all neutron stars begin as.

Ask yourself: How do you think scientists are like detectives?

3mins.

Discover more about the weird physics of neutron stars. 

Ask yourself: What are you curious to learn more about neutron stars?

3mins.

What happens if you get too close to a neutron star? Go on a road trip through spacetime with Chuck, the galactic crash test dummy, to find out.

Ask yourself: Would you ever want to take a vacation on a neutron star?

5mins.

Watch Jocelyn Bell tell the story about how she discovered pulsars  and learn about how pulsars got their name.

Ask yourself: If you discovered a mysterious new object in space, what would you name it?

120mins.

 

Become a pulsar hunter and help scientists discover new pulsars hidden in radio data.

Ask yourself: Why do you think scientists want to study pulsars?

Senior Astronomer Playlist (teens 13-15/adults)
TimeActivity
35mins.

Be a space detective and figure out who – or what – is behind the exploding stars that all neutron stars begin as. Then, watch this TED-Ed video to discover more about the lifecycle of a neutron star.  

Ask yourself: How do you think scientists are like detectives?

10mins.

Watch Jocelyn Bell tell the story about how she discovered pulsars. Read this National Geographic article about Jocelyn Bell to dig deeper.

Ask yourself: What do you think will be the next great discovery in astronomy?

15mins.

Have you ever wondered what pulsars sound like? Watch this lecture given by astrophysicist Dr. Victoria Kaspi from the 26:36 mark to find out! Be sure to stay to listen to the choir of pulsars living in the globular cluster Terzan 5 beginning at 30:57.

If you’re curious about what a pulsar looks like, check out the first ever map of a pulsar’s surface made using data from NASA’s NICER mission.

Ask yourself: What are you curious to learn more about neutron stars?

5mins.

Scientists have just found what they believe to be the youngest neutron star yet discovered. Meet the baby star here.

Ask yourself: Do you have any ideas about what a neutron star might look like as it gets older?

120mins.

 

Become a pulsar hunter and help scientists discover new pulsars hidden in radio data. Learn more about this citizen science project here and start classifying radio data here.

Ask yourself: Why do you think scientists want to study pulsars?