What’s Inside A ‘Dead’ Star?

What’s Inside a ‘Dead’ Star?

Matter makes up all the stuff we can see in the universe, from pencils to people to planets. But there’s still a lot we don’t understand about it! For example: How does matter work when it’s about to become a black hole? We can’t learn anything about matter after it becomes a black hole, because it’s hidden behind the event horizon, the point of no return. So we turn to something we can study – the incredibly dense matter inside a neutron star, the leftover of an exploded massive star that wasn’t quite big enough to turn into a black hole.

Our Neutron star Interior Composition Explorer, or NICER, is an X-ray telescope perched on the International Space Station. NICER was designed to study and measure the sizes and masses of neutron stars to help us learn more about what might be going on in their mysterious cores.

When a star many times the mass of our Sun runs out of fuel, it collapses under its own weight and then bursts into a supernova. What’s left behind depends on the star’s initial mass. Heavier stars (around 25 times the Sun’s mass or more) leave behind black holes. Lighter ones (between about eight and 25 times the Sun’s mass) leave behind neutron stars.

Neutron stars pack more mass than the Sun into a sphere about as wide as New York City’s Manhattan Island is long. Just one teaspoon of neutron star matter would weigh as much as Mount Everest, the highest mountain on Earth!

These objects have a lot of cool physics going on. They can spin faster than blender blades, and they have powerful magnetic fields. In fact, neutron stars are the strongest magnets in the universe! The magnetic fields can rip particles off the star’s surface and then smack them down on another part of the star. The constant bombardment creates hot spots at the magnetic poles. When the star rotates, the hot spots swing in and out of our view like the beams of a lighthouse.

Neutron stars are so dense that they warp nearby space-time, like a bowling ball resting on a trampoline. The warping effect is so strong that it can redirect light from the star’s far side into our view. This has the odd effect of making the star look bigger than it really is!

NICER uses all the cool physics happening on and around neutron stars to learn more about what’s happening inside the star, where matter lingers on the threshold of becoming a black hole. (We should mention that NICER also studies black holes!)

Scientists think neutron stars are layered a bit like a golf ball. At the surface, there’s a really thin (just a couple centimeters high) atmosphere of hydrogen or helium. In the outer core, atoms have broken down into their building blocks – protons, neutrons, and electrons – and the immense pressure has squished most of the protons and electrons together to form a sea of mostly neutrons.

But what’s going on in the inner core? Physicists have lots of theories. In some traditional models, scientists suggested the stars were neutrons all the way down. Others proposed that neutrons break down into their own building blocks, called quarks. And then some suggest that those quarks could recombine to form new types of particles that aren’t neutrons!

NICER is helping us figure things out by measuring the sizes and masses of neutron stars. Scientists use those numbers to calculate the stars’ density, which tells us how squeezable matter is!

Let’s say you have what scientists think of as a typical neutron star, one weighing about 1.4 times the Sun’s mass. If you measure the size of the star, and it’s big, then that might mean it contains more whole neutrons. If instead it’s small, then that might mean the neutrons have broken down into quarks. The tinier pieces can be packed together more tightly.

NICER has now measured the sizes of two neutron stars, called PSR J0030+0451 and PSR J0740+6620, or J0030 and J0740 for short.

J0030 is about 1.4 times the Sun’s mass and 16 miles across. (It also taught us that neutron star hot spots might not always be where we thought.) J0740 is about 2.1 times the Sun’s mass and is also about 16 miles across. So J0740 has about 50% more mass than J0030 but is about the same size! Which tells us that the matter in neutron stars is less squeezable than some scientists predicted. (Remember, some physicists suggest that the added mass would crush all the neutrons and make a smaller star.) And J0740’s mass and size together challenge models where the star is neutrons all the way down.

So what’s in the heart of a neutron star? We’re still not sure. Scientists will have to use NICER’s observations to develop new models, perhaps where the cores of neutron stars contain a mix of both neutrons and weirder matter, like quarks. We’ll have to keep measuring neutron stars to learn more!

Keep up with other exciting announcements about our universe by following NASA Universe on Twitter and Facebook.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

Vote for Your Favorite Astronaut Picture: Tournament Earth 2021

It is that time of year again…Tournament Earth is back! This year, NASA Earth Observatory has chosen a new theme for the tournament: astronaut photography. Choose your favorite image here.

For more than 20 years, astronauts have been shooting photos of Earth from the International Space Station that highlight the planet’s beauty, complexity, and vulnerabilities. So which are the most unforgettable ones? Over the next five weeks (March 8-April 13), you can help decide.

How can you get involved? It’s easy as 1…2…3!

1. Read and Vote.

Not sure which image to vote for because they are ALL so captivating? Read the intriguing stories behind the images to help you decide! You can access the stories by clicking on the image headlines on the voting page: https://earthobservatory.nasa.gov/tournament-earth

For instance, the Stars in Motion image is actually a compilation of 72 photographs. And some of the night lights around Bangkok, Thailand, actually show fishing boats as well as city lights.

2. Fill out your bracket.

Think you know which photo will win it all? Fill out a #TournamentEarth bracket with your predictions and challenge friends! Then share your predictions with NASAEarth on our blog, Twitter, Facebook, Instagram, or right here on Tumblr!

We can’t offer a trip to the Moon, but bragging rights are forever if you can pick the champion. Download a more print-friendly version of the bracket here.

3. View the results…and vote again!

Tournament Earth will have five rounds, and round one is currently underway. Voting for the following rounds begins on Tuesdays and will be open for six days. We will update our social media channels (including right here on Tumblr!) with the newest matchups. Check this space to see how your favorite images did. Then vote until we crown a champion on April 13, 2021.

See all of the images and vote HERE. Follow @NASAEarth on social media for updates.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

829 notes View Post

doctarjaferson

3 years ago

Édouard Debat-Ponsan, La fille de Jephté. 1876, oil on canvas.

Musée des Beaux-Arts

6 notes View Post

doctarjaferson

2 years ago

I hope you’re all being gentle with yourself

1K notes View Post

doctarjaferson

3 years ago

sometimes losing people makes u find urself

11K notes View Post

doctarjaferson

1 year ago

13K notes View Post

doctarjaferson

4 years ago

Best Study Tips To Get Better Grades (According to me)

Need study tips? Are you struggling to keep up in class? When you study you don't feel you learn much or anything at all? Getting better grades? Being more prepared than others?

Well. Me too.

So I did these things.

1- SING OUT LOUND! No, Wait! My brother does that. It's Read Out Loud

Be YOUR OWN TEACHER. Why? Good question, perhaps one of the reason can be MY TEACHER LEAVES THINGS OUT.

- Speaking the content out loud helps you to understand it better. Reciting out the words in YOUR OWN WORDS helps a lot. You learn aspects and even learn it far better than when you read a book. - When you speak the lesson or chapter out loud you are processing it as you speak. Think of it like you are giving a speech. Don't you want your speech to be as effective as possible? And how do you make it so effective? By getting authentic information of course!

2-Flash notes.

Make flash notes. The best time to make them is as soon as a new chapter starts. If you are an Edexcel or Cambridge student, I'm sure you will understand just how important the specification is. Even the books has topics at the start of every chapter.

Use each point to make relevant notes on the specifications, this way you can easily know which main points of the topic if stated. Making these flash notes also help you revise and learn as you make them.

Let me know if you wish to know how to best make Flash Notes.

I will make sure to use an example and help you make them as well as link sites to help you better.

3-Practice Makes Perfect Or So They Say.

Hold it! Stop! Don't hit that back button just yet. This is annoying. So annoying but so desperately needed. You can't get good at Math with doing only one question a day. You need to practice, practice and practice. Study the concept, the method, relevant keywords. Know it so well you can dream of them and write them in your sleep. YOU NEED IT.

Math - those one-page questions need to be practiced at least 3-4 times until you learn it well enough. It seems like a lot of effort, and at times too much to handle and Math is like that but from a person with experience, doing just one question a day can take you up the ladder of improvement. Physics - questions need a to be revised and checked, especially those that voice out the same question. The question maybe same but they may have a different method of getting the answer. Chemistry - REVISE THE EQUATIONS. Think of the equations as the key aspect to breathing. One single thing wrong you lose a mark. AND EVERY MARK COUNTS. Biology - KEY TERMS. Key terms are so important, you have no idea. You cannot go in a Biology exam without those terms. At times the teachers won't even tell you those terms, So, those terms are so important you have no idea.

If you want to understand this better, do let me know. I will do my best to help you understand it better.

4-Past Papers.

Once while doing a paper I was quite confident I would pass, until I got my paper back. Not only was my score low, but it was low due to certain answers not accepted by the paper. How come? They were the same points my teacher had told me about. Everything she taught, then why the low grade? Simple, because she never mentioned the answers that will be accepted in the paper. Some of the answers were never taught in class. Often times teachers do not mention certain points that are relevant to the papers and so students lose marks.

By attempting the papers, you understand what the examiner is looking for and how to best attempt the questions.

Tip: Pay attention to the reject part of the marking scheme. They help you understand the paper pattern and how best to assess the paper.

5-Make Note of The Hard Questions.

When you see that one question with at least 6-7 or 10-12 marks. NOTE THEM DOWN. Why? Simple they aid you when you need them most. Best example I have for you if the most recent one I did.

When studying for Chemistry Unit 5, those questions with even 5 marks that seem really important and you have not done in class before, have them in a note book. This lets you know what can and will come in the paper and how you must asset them.

Say that question where you must find the sides of the shape in Math. Trigonometry questions, find base from plane, those find the “X” question and many more. If you cannot solve them or have trouble solving them and are taking a long time. NOTE THEM DOWN.

Have it in a notebook, with question and answer. Make it so when you come to revise later you can understand and figure out a way to gain those marks more easily.

I hope all this helps.

124 notes View Post

doctarjaferson

1 month ago