How Dangerous are Nearby Supernovae to Life on Earth?

A composite image of SN 1987A from Hubble, Chandra, and ALMA. Image Credit: By ALMA (ESO/NAOJ/NRAO)/A. Angelich. Visible light image: the NASA/ESA Hubble Space Telescope. X-Ray image: The NASA Chandra X-Ray Observatory - http://www.eso.org/public/images/eso1401a/, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=30512379

Life and supernovae don’t mix.

From a distance, supernovae explosions are fascinating. A star more massive than our Sun runs out of hydrogen and becomes unstable. Eventually, it explodes and releases so much energy it can outshine its host galaxy for months.

But space is vast and largely empty, and supernovae are relatively rare. And most planets don’t support life, so most supernovae probably explode without affecting living things.

But a new study shows how one type of supernova has a more extended reach than thought. And it could have consequences for planets like ours.

Continue reading “How Dangerous are Nearby Supernovae to Life on Earth?”

Astronomers Chart the Influence of Dark Matter and Dark Energy on the Universe by Measuring Over 1,500 Supernovae

Artist view of a supernova explosion. Credit: NASA

In 2011, the Nobel Prize in physics was awarded to Perlmutter, Schmidt, and Reiss for their discovery that the universe is not just expanding, it is accelerating. The work supported the idea of a universe filled with dark energy and dark matter, and it was based on observations of distant supernovae. Particularly, Type Ia supernovae, which have consistent light curves we can use as standard candles to measure cosmic distances. Now a new study of more than 1,500 supernovae confirms dark energy and dark matter, but also raises questions about our cosmological models.

Continue reading “Astronomers Chart the Influence of Dark Matter and Dark Energy on the Universe by Measuring Over 1,500 Supernovae”

Astronomers Just saw the Most Powerful Gamma-ray Burst Ever Recorded

Artist’s impression of a gamma-ray burst. Credit: ESO/A. Roquette

Gamma-ray bursts (GRBs) are one of the most mysterious transient phenomena facing astronomers today. These incredibly energetic bursts are the most powerful electromagnetic events observed since the Big Bang and can last from a few milliseconds to many hours. Whereas longer bursts are thought to occur during supernovae, when massive stars undergo gravitational collapse and shed their outer layer to become black holes, shorter events have also been recorded when massive binary objects (black holes and neutron stars) merge.

These bursts are characterized by an initial flash of gamma rays and a longer-lived “afterglow” typically emitted in X-ray, ultraviolet, radio, and other longer wavelengths. In the early-morning hours on October 14th, 2022, two independent teams of astronomers using the Gemini South telescope observed the aftermath of a GRB designated GRB221009A. Located 2.4 billion light-years away in the Sagitta constellation, this event was perhaps the closes and most powerful explosion ever recorded and was likely triggered by a supernova that gave birth to a black hole.

Continue reading “Astronomers Just saw the Most Powerful Gamma-ray Burst Ever Recorded”

Can Astronomers Predict Which Stars Are About to Explode as Supernovae?

In a recent study submitted to High Energy Astrophysical Phenomena, a team of researchers from Japan discuss strategies to observe, and possibly predict precursor signatures for an explosion from Local Type II and Galactic supernovae (SNe). This study has the potential to help us better understand both how and when supernovae could occur throughout the universe, with supernovae being the plural form of supernova (SN). But just how important is it to detect supernovae before they actually happen?

Continue reading “Can Astronomers Predict Which Stars Are About to Explode as Supernovae?”

Recent Supernovae Produced Giant Cavities in the Orion Nebula

This image of the Orion Nebula shows the puzzilng Barnard's Loop feature, a structure made of gas first identified in 1898, Image Credit: Michael Foley

The Orion Nebula is a well-known feature in the night sky and is visible in small backyard telescopes. Orion is a busy place. The region is known for active star formation and other phenomena. It’s one of the most scrutinized features in the sky, and astronomers have observed all kinds of activity there: planets forming in protoplanetary disks, stars beginning their lives of fusion inside collapsing molecular clouds, and the photoevaporative power of massive hot stars as they carve out openings in clouds of interstellar gas.

But supernova explosions are leaving their mark on the Orion Nebula too. New research says supernovae explosions in recent astronomical history are responsible for a mysterious feature first formally identified in the night sky at the end of the 19th century. It’s called Barnard’s Loop, and it’s a gigantic loop of hot gas as large as 300 light-years across.

Continue reading “Recent Supernovae Produced Giant Cavities in the Orion Nebula”

Astronomers Find a Star That Contains 65 Different Elements

This is an image of M80, an ancient globular cluster of stars. Since these stars formed in the early universe, their metallicity content is very low. This means that gas giants like Jupiter would be rare or non-existent here, while brown dwarfs are likely plentiful. Image: By NASA, The Hubble Heritage Team, STScI, AURA - Great Images in NASA Description, Public Domain, https://commons.wikimedia.org/w/index.php?curid=6449278
This is an image of M80, an ancient globular cluster of stars. Since these stars formed in the early universe, their metallicity content is very low. This means that gas giants like Jupiter would be rare or non-existent here, while brown dwarfs are likely plentiful. Image: By NASA, The Hubble Heritage Team, STScI, AURA - Great Images in NASA Description, Public Domain, https://commons.wikimedia.org/w/index.php?curid=6449278

Have you ever held a chunk of gold in your hand? Not a little piece of jewelry, but an ounce or more? If you have, you can almost immediately understand what drives humans to want to possess it and know where it comes from.

We know that gold comes from stars. All stars are comprised primarily of hydrogen and helium. But they contain other elements, which astrophysicists refer to as a star’s metallicity. Our Sun has a high metallicity and contains 67 different elements, including about 2.5 trillion tons of gold.

Now astronomers have found a distant star that contains 65 elements, the most ever detected in another star. Gold is among them.

Continue reading “Astronomers Find a Star That Contains 65 Different Elements”

A Recently Discovered Double Binary System is Unstable. Stars Could Collide, Leading to a Supernova

Artist view of an orbiting binary star. Credit: ESO/L. Calçada

Multiple star systems are very common in the Milky Way. While most of these systems are binary systems consisting of two stars, others contain three, four, or even six stars. These systems tend to be pretty stable since unstable systems tend to break apart or merge fairly quickly, but sometimes you can get a kind of meta-stable system. One that lasts long enough for stars to evolve while still being stable in the end. And that end could be a supernova.

Continue reading “A Recently Discovered Double Binary System is Unstable. Stars Could Collide, Leading to a Supernova”

We can Probably Find Supernovae Enhanced by Gravitational Lensing, We Just Need to Look

Using the microlensing metthod, a team of astrophysicists have found the first extra-galactic planets! Credit: NASA/Tim Pyle

Gravitational lensing provides an opportunity to see supernovae and other transients much farther than we normally can. A new research proposal outlines a plan to use a comprehensive catalog of strong gravitational lenses to capture these rare events at extreme distances.

Continue reading “We can Probably Find Supernovae Enhanced by Gravitational Lensing, We Just Need to Look”

Nearby Supernovae Exploded Just a few Million Years Ago, Leading to a Wave of Star Formation Around the Sun

Artist's illustration of the Local Bubble with star formation occurring on the bubble's surface. Scientists have now shown how a chain of events beginning 14 million years ago with a set of powerful supernovae led to the creation of the vast bubble, responsible for the formation of all young stars within 500 light years of the Sun and Earth. Credit: Leah Hustak (STScI)

The Sun isn’t the only star in this galactic neighbourhood. Other stars also call this neighbourhood home. But what’s the neighbourhood’s history? What triggered the birth of all those stars?

A team of astronomers say they’ve pieced the history together and identified the trigger: a series of supernovae explosions that began about 14 million years ago.

Continue reading “Nearby Supernovae Exploded Just a few Million Years Ago, Leading to a Wave of Star Formation Around the Sun”

Nearby Supernovae Were Essential to Life on Earth

Distant past supernovae could be linked by cosmic ray particles to climate change on Earth and changes in biodiversity. Courtesy: Henrik Svensmark, DTU Space.
Distant past supernovae could be linked by cosmic ray particles to climate change on Earth and changes in biodiversity. Courtesy: Henrik Svensmark, DTU Space.

It’s almost impossible to comprehend a supernova explosion’s violent, destructive power. An exploding supernova can outshine its host galaxy for a few weeks or even months. That seems almost impossible when considering that a galaxy can contain hundreds of billions of stars. Any planet too close to a supernova would be completely sterilized by all the energy released, its atmosphere would be stripped away, and it may even be shredded into pieces.

But like many things in nature, it all comes down to dose.

A certain amount of supernova activity might be necessary for life to exist.

Continue reading “Nearby Supernovae Were Essential to Life on Earth”