Tag Archives: supernova

The Supernova That Wasn’t: A Tale of 3 Cosmic Eruptions

Combining images taken with the Hubble Space Telescope over more than 20 years, a team of UA researchers has discovered that Eta Carinae, a very massive star system that has puzzled astronomers since it erupted in a supernova-like event in the mid-19th century, has a past that’s much more violent than they thought. The findings help rewrite the story of how this iconic and mysterious star system came to be and present a critical piece of the puzzle of how very massive stars die. (more…)

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The Supernova That Cried Wolf

A luminous supernova in a galaxy 67 million light years away from us has finally exploded for good, a UA-led team of astronomers has discovered. This event sheds light on how massive stars end their lives.

Astronomers have announced that a massive star, which they have watched repeatedly mimic a supernova since 2009, has finally exploded for real.

The report was presented at the American Astronomical Society meeting in Long Beach, Calif. by Jon Mauerhan of the Steward Observatory at the University of Arizona, in collaboration with Nathan Smith, also of the UA, and Alex Filippenko of the University of California, Berkeley.

The result is of special interest because it provides new critical information on the final death throes of massive stars in the years leading up to their explosion. The work has been accepted for publication in the Monthly Notices of the Royal Astronomical Society. (more…)

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Exploding Star Missing From Formation of Solar System

A new study published by University of Chicago researchers challenges the notion that the force of an exploding star prompted the formation of the solar system.

In this study, published online last month in Earth and Planetary Science Letters, authors Haolan Tang and Nicolas Dauphas found the radioactive isotope iron 60 — the telltale sign of an exploding star—low in abundance and well mixed in solar system material. As cosmochemists, they look for remnants of stellar explosions in meteorites to help determine the conditions under which the solar system formed. (more…)

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Supernovae of the Same Brightness, Cut From Vastly Different Cosmic Cloth

Berkeley Lab researchers make historic observation of rare Type 1a Supernova

Exploding stars called Type 1a supernova are ideal for measuring cosmic distance because they are bright enough to spot across the Universe and have relatively the same luminosity everywhere. Although astronomers have many theories about the kinds of star systems involved in these explosions (or progenitor systems), no one has ever directly observed one—until now.

In the August 24 issue of Science, the multi-institutional Palomar Transient Factory (PTF) team presents the first-ever direct observations of a Type 1a supernova progenitor system. Astronomers have collected evidence indicating that the progenitor system of a Type 1a supernova, called PTF 11kx, contains a red giant star. They also show that the system previously underwent at least one much smaller nova eruption before it ended its life in a destructive supernova. The system is located 600 million light years away in the constellation Lynx. (more…)

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How Megakaryocytes Get so Big — and The Bad Things That Happen When They Don’t

Yale researchers have discovered how megakaryocytes — giant blood cells that produce wound-healing platelets — manage to grow 10 to 15 times larger than other blood cells.

The findings, to be published March 13 in the journal Developmental Cell, also hint at how a malfunction in this process may cause a form of leukemia. (more…)

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Echoes From an Exploding Star

*Astronomers watch a delayed broadcast of a powerful stellar eruption.*

Astronomers are watching the astronomical equivalent of streaming live video of a spectacular outburst from the unstable, behemoth double-star system Eta Carinae, which initially was seen on Earth nearly 170 years ago.

Dubbed the “Great Eruption,” the outburst lasted from 1837 to 1858 and caught the attention of sky-watchers at the time, including the British astronomer Sir John Herschel. He did not have the benefit of the imaging cameras and spectrographs that modern astronomers use to learn about stars, so we only have a historical record of the star’s visual brightness. (more…)

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Star Explosion Leaves Behind a Rose

About 3,700 years ago, people on Earth would have seen a brand-new bright star in the sky. It slowly dimmed out of sight and was eventually forgotten, until modern astronomers later found its remains, called Puppis A. In this new image from NASA’s Wide-field Infrared Survey Explorer (WISE), Puppis A looks less like the remains of a supernova explosion and more like a red rose.

Puppis A (pronounced PUP-pis) was formed when a massive star ended its life in a supernova, the most brilliant and powerful form of an explosion in the known universe. The expanding shock waves from that explosion are heating up the dust and gas clouds surrounding the supernova, causing them to glow and appear red in this infrared view. While much of the material from that original star was violently thrown out into space, some of it  remained in an incredibly dense object called a neutron star. This particular neutron star (too faint to be seen in this image) is moving inexplicably fast: over 3 million miles per hour! Astronomers are perplexed over its absurd speed, and have nicknamed the object the “Cosmic Cannonball.” (more…)

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