NASA’s Chandra Finds Source of Star’s Mysterious Outbursts

science & techNASA

NASA’s Chandra Finds Source of Star’s Mysterious Outbursts

the gist

A giant, unstable star called AT 2016blu, in the galaxy NGC 4559 about 30 million light-years away, brightens sharply about every 113 days. Astronomers recorded at least 27 such bursts between 2012 and 2026. X-ray data from the Chandra observatory has now revealed why: a hidden companion, either a stellar-mass black hole or a neutron star, orbits the star every 113 days and pulls material off it. The star weighs at least 33 times the Sun and is a luminous blue variable, a hot massive star prone to eruptions. Its flares look like supernovae but leave the star intact, earning it the label supernova impostor. This is the first X-ray detection of such a star and the first with a compact companion.

how it works

On each 113-day orbit the companion swings close to the massive star and strips gas from its swollen outer layers. The sudden release of material brightens the system, then it fades until the next close approach. Chandra caught the system at the right time to see the X-rays from the companion.

so what

It solves a 15-year puzzle and shows that some of these erratic stars are in fact binaries, where a close encounter on each orbit triggers the outburst. That helps explain how massive stars lose mass and may point to how black hole and neutron star pairs form.

fun fact

Eta Carinae, the best-known luminous blue variable, produced a giant eruption in the 1840s that briefly made it the second-brightest star in the sky.

Credit: NASA

Image: NASA

source: NASA ↗

historyThe Public Domain Review1909 · United States

D. W. Griffith’s A Corner in Wheat (1909)

the gist

In 1909 D. W. Griffith made a 14-minute film about a speculator who corners the wheat market and doubles the price of bread. A farmer sows his field while a 'Wheat King' gambles in the Chicago wheat pit; bakers raise the loaf from five cents to ten and the poor line up for bread. Griffith cut back and forth between the farm, the feast and the breadline, a technique called parallel editing, so audiences saw both ends of the economy at once. The film drew on Frank Norris's stories and on a real scheme: months earlier Chicago financier James Patten had cornered wheat, sent bread prices up and made about $5 million, roughly $185 million today.

how it works

To corner a market, a trader buys up most of the available supply and the futures contracts that promise more. Anyone who has to deliver the commodity must then buy from the cornerer at whatever price is demanded. The trader profits until the stock is released or the scheme collapses.

so what

A century on, it still shows how markets can be rigged by someone who controls supply, and how the people at either end, farmers and eaters, pay for it. It also helped establish editing as a way to argue a point, not just tell a story.

the bigger pattern

Corners have recurred whenever supply could be locked up, from the Hunt brothers' attempt on silver in 1979 to 1980 to the 'Black Friday' gold panic of 1869. Many such schemes end by collapsing, and the response is often new rules on speculation.

fun fact

In the film the Wheat King dies by falling into a grain elevator and being buried in the wheat he hoarded, an ending borrowed from Norris's novel The Octopus.

more on this

background

A Corner in Wheat is a 1909 American short silent film which tells of a greedy tycoon who tries to corner the market in wheat, destroying the lives of the people who can no longer afford to buy bread. It was directed by D. W. Griffith and adapted by Griffith and Frank E. Woods from a novel and a short story by Frank Norris, titled The Pit and "A Deal in Wheat". Griffith may have had a real-life inspiration: six months earlier, James A. Patten had actually cornered the market in wheat, and in some cities, the price of bread doubled from five cents to ten, just as in the movie.

In 1994, A Corner in Wheat was selected for preservation in the United States National Film Registry by the Library of Congress as being "culturally, historically, or aesthetically significant".

From Wikipedia: A Corner in Wheat (CC BY-SA 4.0) ↗

see

D. W. Griffith, Public domain, via Wikimedia Commons

G. W. Bitzer (cinematographer) under employment of the Biog…, Public domain, via Wikimedia Commons

DS Pugh, CC BY-SA 2.0, via Wikimedia Commons

Image: The Public Domain Review

source: The Public Domain Review ↗

12 min

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Usman Khawaja refuses to answer Sandpapergate question about Pat Cummins | 7.30

from ABC News In-depth

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A new autobiography by former Test cricketer Usman Khawaja has made explosive revelations about the Australian Test team's 2018 ball-tampering saga in South Africa.

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