Meet the Woman Who Discovered the Composition of the Stars

In 1925, Cecilia Payne put forth her Ph.D thesis addressing one of the most fundamental topics in all of astrophysics: the composition of the stars.

The 25-year-old had entered her field somewhat by chance. After feeling uncertain about which science track to pursue at Cambridge, Payne happened to attend a lecture at which Arthur Eddington relayed the findings of a recent expedition. He announced that his observations of a solar eclipse proved Einstein’s Theory of General Relativity, which had been published years earlier without physical evidence. After this brush with the thrill of astrophysics, Payne was hooked.

Eddington ultimately helped lead Payne’s foray into astronomy. But it was difficult for women to advance in British academia, so Payne moved to the United States and became a graduate fellow at Harvard College Observatory.

In the years that followed, Payne was able to decode the stellar spectra and determine chemical components of stars. Her findings—that they were almost entirely comprised of hydrogen and helium, with only 2% of their mass coming from other, heavier elements—flew in the face of conventional wisdom. Until then, scientists believed the composition of the Earth and stars were similar.

The determination was so revolutionary that when Payne showed her supervisor, Harlow Shapley, he consulted a colleague at Princeton who replied that the result was impossible, despite the fact that no flaws could be found in her work. As a precautionary measure, Payne included a line in her thesis that stated the results were “almost certainly not real.”

But of course, they were. In time, Payne’s colleagues, the field of astrophysics, and the world came to recognize her achievement, though that didn’t mean her struggle for acknowledgment was over. It took until 1956 for Payne to be made a full professor (the first female at Harvard to receive that title) and chair of the Astronomy Department. She was awarded the Henry Norris Russell Prize by the American Astronomical Society in 1976.

During her acceptance speech for the award, Payne said: “The reward of the young scientist is the emotional thrill of being the first person in the history of the world to see something or to understand something ...The reward of the old scientist is the sense of having seen a vague sketch grow into a masterly landscape.”

[h/t American Museum of Natural History]

How Often Is 'Once in a Blue Moon'? Let Neil deGrasse Tyson Explain

From “lit” to “I can’t even,” lots of colloquialisms make no sense. But not all confusing phrases stem from Millennial mouths. Take, for example, “once in a blue moon”—an expression you’ve likely heard uttered by teachers, parents, newscasters, and even scientists. This term is often used to describe a rare phenomenon—but why?

Even StarTalk Radio host Neil deGrasse Tyson doesn’t know for sure. “I have no idea why a blue moon is called a blue moon,” he tells Mashable. “There is nothing blue about it at all.”

A blue moon is the second full moon to appear in a single calendar month. Astronomy dictates that two full moons can technically occur in one month, so long as the first moon rises early in the month and the second appears around the 30th or 31st. This type of phenomenon occurs every couple years or so. So taken literally, “Once in a blue moon” must mean "every few years"—even if the term itself is often used to describe something that’s even more rare.

[h/t Mashable]

Neutron Star Collision Sheds Light on the Strange Matter That Weighs a Billion Tons Per Teaspoon
Two neutron stars collide.
Two neutron stars collide.

Neutron stars are among the many mysteries of the universe scientists are working to unravel. The celestial bodies are incredibly dense, and their dramatic deaths are one of the main sources of the universe’s gold. But beyond that, not much is known about neutron stars, not even their size or what they’re made of. A new stellar collision reported earlier this year may shed light on the physics of these unusual objects.

As Science News reports, the collision of two neutron stars—the remaining cores of massive stars that have collapsed—were observed via light from gravitational waves. When the two small stars crossed paths, they merged to create one large object. The new star collapsed shortly after it formed, but exactly how long it took to perish reveals keys details of its size and makeup.

One thing scientists know about neutron stars is that they’re really, really dense. When stars become too big to support their own mass, they collapse, compressing their electrons and protons together into neutrons. The resulting neutron star fits all that matter into a tight space—scientists estimate that one teaspoon of the stuff inside a neutron star would weigh a billion tons.

This type of matter is impossible to recreate and study on Earth, but scientists have come up with a few theories as to its specific properties. One is that neutron stars are soft and yielding like stellar Play-Doh. Another school of thought posits that the stars are rigid and equipped to stand up to extreme pressure.

According to simulations, a soft neutron star would take less time to collapse than a hard star because they’re smaller. During the recently recorded event, astronomers observed a brief flash of light between the neutron stars’ collision and collapse. This indicates that a new spinning star, held together by the speed of its rotation, existed for a few milliseconds rather than collapsing immediately and vanishing into a black hole. This supports the hard neutron star theory.

Armed with a clearer idea of the star’s composition, scientists can now put constraints on their size range. One group of researchers pegged the smallest possible size for a neutron star with 60 percent more mass than our sun at 13.3 miles across. At the other end of the spectrum, scientists are determining that the biggest neutron stars become smaller rather than larger. In the collision, a larger star would have survived hours or potentially days, supported by its own heft, before collapsing. Its short existence suggests it wasn’t so huge.

Astronomers now know more about neutron stars than ever before, but their mysterious nature is still far from being fully understood. The matter at their core, whether free-floating quarks or subatomic particles made from heavier quarks, could change all of the equations that have been written up to this point. Astronomers will continue to search the skies for clues that demystify the strange objects.

[h/t Science News]


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