Discover Top Posts Tagged with #type ia

Supernova Remnant 0509-68.7 [N103B]

The remnant is the small, reddish dust cloud in the upper right corner. It lies 160,000 light years from Earth, in a galaxy known as the Large Magellanic Cloud. The mass of stars in the lower left corner is part of the star cluster NGC 1850. (NASA.gov)

#supernova remnant #type ia #Supernova Remnant 0509-68.7 #N103B #large magellanic cloud #hubble #NASA/ESA #Astronomy #space blog #NGC 1850 #galaxy #dying star #supernova #mine

Could a new type of supernova eliminate dark energy?

"Imagine you had a box of candles that you thought were all identical to one another: you could light them up, put them all at different distances, and immediately, just from measuring the brightness you saw, know how far away they are. That’s the idea behind a standard candle in astronomy, and why type Ia supernovae are so powerful.

But now, imagine that these candle flames aren’t all the same brightness! Suddenly, some are a little brighter and some are a little dimmer; you have two classes of candles, and while you might have more of the brighter ones close by, you might have more of the dimmer ones far away. That’s what we think we’ve just discovered with supernovae: there are actually two separate classes of them, where one’s a little brighter in the blue/UV, and one’s a little brighter in the red/IR, and the light curves they follow are slightly different. This might mean that, at high redshifts (large distances), the supernovae themselves are actually intrinsically fainter, and not that they’re farther away."

Back in the 1990s, scientists were quite surprised to find that when they measured the brightness and redshifts of distant supernovae, they appeared fainter than one would expect, leading us to conclude that the Universe was expanding at an accelerating rate to push them farther away. But a 2015 study put forth a possibility that many scientists dreaded: that perhaps these distant supernovae were intrinsically different from the ones we had observed nearby. Would that potentially eliminate the need for dark energy altogether? Or would it simply change ever-so-slightly the amount and properties of dark energy we required to explain modern cosmology? A full analysis shows that dark energy is here to stay, regardless of the supernova data.

#dark energy #supernova #supernovae #type Ia #white dwarf #chandrasekhar #limit #physics #astrophysics #universe #expansion #acceleration #cosmology

The Milky Way’s most recent supernova was hidden... until now!

"Close to the galactic center, the supernova remnant G1.9+0.3 was first discovered in the radio thanks to the Very Large Array (VLA), with its origin unknown. The fact that it was so small on the sky, despite being at a distance of 25,000 light years, brought up the possibility that this was a very young supernova: perhaps the youngest of all supernovae in the Milky Way. Follow-up observations took place in the 2000s with the Two-Micron All-Sky Survey in the infrared and with the Chandra X-ray observatory, where a wonderful surprise came to light: this supernova remnant was expanding at an incredible pace!

In 1604, Kepler’s supernova went off, the last Milky Way supernova visible to naked-eye skywatchers here on Earth. Yet since the development of radio and X-ray astronomy, other, more recent supernova remnants in our galaxy have been found. They’ve only been invisible to the naked eye because of the galactic gas and dust that blocks their visible light. In 1984/5, the VLA discovered the most recent known remnant near the galactic center, and follow-up observations showed a rapid expansion. The most recent data not only dates this remnant to be only 110 years old, but it teaches us that it’s a Type Ia supernova that formed from the merger of two white dwarfs. The standard model — of one white dwarf accruing matter from a binary companion — may not only be a minority of Type Ia events, perhaps it doesn’t occur at all.

#supernova #milky way #type ia #astronomy #stars #supernovae #white dwarf #colliding #merger #space #VLA #chandra #nasa

Cosmic Light Bulbs

The brilliant explosions of dead stars have been used for years to illuminate the far-flung reaches of our cosmos. The explosions, called Type Ia supernovae, allow astronomers to measure the distances to galaxies and measure the ever-increasing rate at which our universe is stretching apart.

But these tools aren’t perfect. In the cosmic hardware store of our universe, improvements are ongoing.…

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#GALEX #Type Ia #White Dwarf

Astronomers Search for Trigger of Nearby Supernova

New data from NASA’s Chandra X-ray Observatory is helping astronomers determine what caused SN 2014J to explode, revealing information about the environment around the star before it exploded.

Cambridge, Massachusetts – New data from NASA’s Chandra X-ray Observatory offer a glimpse into the environment of a star before it exploded earlier this year, and insight into what triggered one of the…

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#Chandra X-ray Observatory #NASA #SN #Type Ia

Using NASA’s Hubble Space Telescope, a team of astronomers has spotted a star system that could have left behind a “zombie star” after an unusually weak supernova explosion.

Type Ia supernovae are events that happen in binary star systems consisting of a "compact object" (usually a white dwarf, the burned-out husk of a formerly sunlike star) and an "evolved star" such as a red giant. If the stars are sufficiently close to one another, the red giant may transfer gas from its outer envelope onto the white dwarf. When a sufficient amount of gas accumulates on the white dwarf, violently detonates, causing an explosion so catastrophic that it destroys the white dwarf entirely. Type Ia's are important cosmic "standard candles" because it is thought they all shine with the same amount of light, enabling us to estimate large distances throughout the Universe.

Theory predicts that sometimes, the explosion energy is right on the hairy edge of "destructive", and leaves behind a remnant in a rare event called a "Type Iax". New Hubble Space Telescope observations might just have seen one of these weak supernovae before it exploded, giving us new insights into the conditions that result in a Type Iax. The results are to be published in the 7 August issue of Nature.