#pulsars

[aloyxwrites]

did you know it was a woman who first discovered pulsars (and helped us study black holes)? and that they gave the nobel prize to her supervisor instead?

jocelyn bell burnell, 1967.

she finally got a $3m prize in 2018 and gave it all away to help underrepresented students become physicists!!

(i randomly discovered this while listening to an audiobook about the universe)

[skycrorg]

🌀⚡🔭 Millisecond pulsars were supposed to be well understood — until now. A new study reveals these ultra-fast spinning stars broadcast radio waves from far beyond their magnetic poles, reaching a turbulent boundary at the edge of their magnetic reach. The findings reshape how we think about the most precise natural clocks in the cosmos. Read the full story at SKYCR.ORG.

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[sciencespectrum]

How do pulsars spin so perfectly in the vast universe?

Pulsars are one of the most fascinating objects in the universe 🌠. Imagine a star collapsing into an incredibly dense neutron star, which spins hundreds of times per second and sends beams of light into space like a cosmic lighthouse 🌟. But how do scientists actually measure these circular rotations, and why is their rhythm so precise? 🌀

Radio telescopes are the main tools used to detect pulsars 📡. Every time a beam of radiation is directed towards Earth, it creates a pulse that we can measure. By carefully recording the time between these pulses ⏱️, scientists can calculate the speed of the pulsar's rotation with incredible accuracy - even down to fractions of a millisecond! Some pulsars are so stable that they rival the accuracy of atomic clocks ⏲️✨.

The secret to their impeccable timing lies in their extreme density and physics. Neutron stars are made up mostly of neutrons, which are packed more tightly than atomic nuclei 💫. This rigid structure reduces wobble. Strong magnetic fields guide the radiation emissions steadily, while the laws of angular momentum keep them spinning smoothly 🧲🔄. Unlike objects on Earth, there is almost no friction in space, so pulsars can maintain their rhythm for millions of years! 🌌

Scientists use these precise cosmic clocks for amazing purposes. They test Einstein's theory of general relativity 🪐, explore the interstellar medium 🌬️, and even help spacecraft navigate through the galaxy 🚀. The next time you look up at the stars, remember that these little spinning giants are keeping perfect time in the cosmic symphony 🌠🎶.

[kittyit]

I Changed Astronomy Forever. He Won the Nobel Prize for It.

Growing up in a Quaker household, Jocelyn Bell Burnell was raised to believe that she had as much right to an education as anyone else. But as a girl in the 1940s in Northern Ireland, her enthusiasm for the sciences was met with hostility from teachers and male students. Undeterred, she went on to study radio astronomy at Glasgow University, where she was the only woman in many of her classes.

In 1967, Burnell made a discovery that altered our perception of the universe. As a Ph.D. student at Cambridge University assisting the astronomer Anthony Hewish, she discovered pulsars — compact, spinning celestial objects that give off beams of radiation, like cosmic lighthouses.

[fullyunsourced]

The incredible power of pulsars

In 1967, astrophysicist Jocelyn Bell found the first signs of extraterrestrial intelligence using a radio telescope array. It picked up a signal coming from space that was a series of pulses exactly every 1.337 seconds. It couldn't be coming from Earth, because the signal source tracked to something in the sky, instead of following Earth's movement.

Well it wasn't quite extraterrestrial life, but it certainly was something extraterrestrial! Bell had discovered a pulsar. Her work would eventually lead to her supervisor, Antony Hewish, receiving a Nobel Prize in Physics (but rather controversially, not Bell herself).

At first, Bell and Hewish didn't really identify the source of the signal, but they certainly didn't believe it could be ETs. They still named their signal "LGM-1", for "Little Green Men". After finding a second pulsing signal, they dropped the ET idea entirely.

Pulsars are just one of those space things that makes my head spin. It's a neutron star that's rotating at an incredible rate while emitting beams of radiation from its magnetic poles. Think of a stellar lighthouse, but spinning faster than you can imagine.

The fastest known pulsar spins at 43,000 revolutions per minute, nearly a quarter the speed of light! Not bad for something maybe up to 32 kilometers in diameter.

A neutron star forms when a collapsing massive star isn't quite big enough to go supernova. When a gigantic star which is spinning slowly collapses, that angular momentum doesn't go away. All that mass shrinks down into the radius of a neutron star, leaving it spinning much, much faster.

The beam is caused by the star's rotation. The rotating magnetic field of the star concentrates protons and electrons on the star, which then turns into a beam at each of the magnetic poles. Emitting this beam costs the star a bit of rotational energy, so eventually the pulsar slows to the point that the beam stop and it's just a boring neutron star.

We do have a use for pulsars! We have better atomic clocks now, but pulsars are an extremely regular timekeeper too. They can be used as a secondary timekeeping source. You can also watch that radiation beam for any gravitational interference, handy for finding things like black holes that can't be observed directly.

There are also things like binary pulsars. Concepts in general relativity (something to do with time being affected by gravity) can be studied by seeing how the beams are mutually affected by the twin stars.

One more creepy thing about pulsars: That regular clock function they have sometimes just.. doesn't work as expected. It speeds up again! It's a 'glitch', where the pulsar speeds up for whatever reason. We don't know why. There are also anti-glitches, where it unexpectedly slows down.

Best guess: The star's core synchronizes with the movement of the crust, where they normally move independently. This transfers some momentum to the crust, which speeds it up.

[to-search-again]

Jocelyn Bell Burnell, who discovered pulsars, at the Mullard Radio Astronomy Observatory at Cambridge University, taken for the Daily Herald newspaper in 1968.

[bytetrending]

New Approach Unlocks Milli-Hertz Gravitational Wave Frontier

Unlocking the Milli-Hertz Universe: A New Era in Gravitational Wave Detection For years, gravitational waves astronomy has revolutionized our understanding of the cosmos. Current detectors like LIGO and Virgo primarily operate at high frequencies, revealing spectacular events such as black hole mergers. However, a vast region of lower frequencies – the milli-Hertz range (mHz) – remains largely…

New Approach Unlocks Milli-Hertz Gravitational Wave Frontier

[mysticalblizzardcolor]

Listen to: Pulsars by John Martini Music

Pulsars

from

Surface of the Sun (Synth Mode Music)

by

John Martini Music