Tag Archives: stars

Watch A Four-Year Timelapse of A Mysterious Cosmic Explosion Captured By the Hubble Telescope (Video)

Back in January of 2002, astronomers witnessed a huge explosion from the star V838 Monocerotis, a red variable star about 20,000 light years away from our Sun.

At first, they thought it was a typical supernova (the explosion of a dying star), but after watching the explosion dim then brighten twice over a period of only a few months (supernovas will usually only dim after the initial bright explosion), astronomers really weren’t sure what they were dealing with.

Check out a time-lapse of the explosion from 2002-2006 below (full screen highly suggested).

So what exactly is going on with this explosion? Well, there are five possibilities that have been proposed so far:

  1. The explosion was a supernova, just a very unique one with a multi-outburst pattern, which would explain the multiple brightening and dimming events. Most scientists agree that the large size and young age of the stars in that region makes this explanation unlikely, however.
  2. The explosion was a thermal pulse. When moderately-sized stars run out of fuel, they explode (in a supernova), leaving behind a dense core of hydrogen and helium. Sometimes this hydrogen and helium core can be re-ignited, illuminating the layers of ejected star material from the supernova explosion. Again, however, the star’s young age makes this possibility unlikely.
  3. Another theory also proposes a helium flash, but one that occurred as a result of thermonuclear processes in a massive supergiant star. Supergiants can be large enough for an outer layer of helium to ignite and start the fusion process without the whole star being destroyed. This theory fits with the star’s age, but it doesn’t seem that V838 Monocerotis had enough mass for this process occur.
  4. Planetary capture: when a star grows to large proportions, it can start consuming nearby planets. The friction generated when a very large planet gets pulled apart by the star’s gravity can produce enough energy to spark deuterium fusion, which releases massive amounts of energy (like what we see in the time-lapse).
  5. The explosion was a result of a mergeburst. Sometimes, in clusters of younger stars (where orbits can be very unstable), two main-sequence stars can collide, creating an explosion similar to the one in the video. The relatively young age of the stars near V838 Monocerotis make this a reasonable possibility, and this hypothesis has also been supported by computer modeling.

It’s awesome to study the stars and find out exactly why they act the way they do, but sometimes explanations can be elusive. So while we search for answers, we should also make sure we take the time to simply enjoy watching this mesmerizing cosmic phenomenon.

(h/t Gizmodo)

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Astronomers Just Witnessed A Massive Cosmic Explosion… 12 Billion Years After It Happened

Supergiants are massive stars with huge amounts of energy, which causes them to expand rapidly. However, all stars eventually reach a limit, after which the gravity of the core is no longer able to hold the star together.

The explosion that follows is known as a supernova (or sometimes a hypernova, if it’s big enough). As the outer portions of the star explode off, the core collapses upon itself.

Nebulas are the remnants of a supernova explosion. This is the Crab Nebula. Click to enlarge

If a star is large enough, the extreme amount of energy produced by this inward collapse forces the star’s core to release high-energy gamma particles. These gamma bursts are the most powerful event so far discovered in the universe. But just how powerful is that?

Well, in just 10 seconds, these gamma ray bursts release more energy than our Earth’s sun will during the entire 10 billion years of its expected lifespan.

On April 19th, in the Davis Mountains of West Texas, the ROTSE-IIIb telescope (owned by Southern Methodist University in Dallas) detected the rare phenomenon in a corner of the sky.

Click to enlarge

The gamma ray burst, classified as GRB 140419A by NASA’s Gamma-ray Coordinates Network, came from a supernova that happened 12.1 billion years ago, not long after the Big Bang (estimated to have occurred 13.8 billion years ago).

Gamma ray burst have only recently been observed. Not only are they at extremely high frequencies, but they also have the shortest wavelengths on the electromagnetic spectrum, making them more difficult to detect. It wasn’t until the 90s that we created a telescope with the technology to detect gamma radiation.

The discovery was published in Science Daily earlier this month. You can read the full story here.

NOTE: The feature image is an artist rendering of a gamma burst. It is, however, based on detailed scientific study of the event.

How to Watch the First Ever Camelopardalid Meteor Shower Tonight (Live Stream)

Starting at around 11 p.m. Eastern time tonight, the Camelopardalid Meteor Shower will be peaking in the night sky. The meteors are the debris left behind by the comet P/209 LINEAR almost two centuries ago.

On May 23/24, Earth will be passing through this trail of debris, which is why the meteors will be visible to us here on Earth tonight for the first time ever. The comets will appear to be coming from the constellation Ursa Major (the Big Dipper).

Astronomers are predicting that the shower could be pretty spectacular, with some estimating as many as 200 meteor sightings per hour. The shower will peak between 2 and 4 a.m. Eastern time tomorrow morning.

If visibility in your area is limited, not to worry. Slooh will be live-streaming the whole event- you can check it out below:

 

What It Looks Like When Two Neutron Stars Rip Each Other Apart to Form a Black Hole (Video)

A neutron star is what’s left behind when a massive star (typically 8-30 times the size of our Sun) explodes into a supernova. These supergiant stars get so large that they are no longer able to remain stable under their own intense gravity, collapsing in on themselves.

The gravity is so massive that it exceeds the strength of the atomic forces within particles, causing them to eject protons and electrons. The ball of neutrons they leave behind is so dense that a teaspoonful of the material would weigh as much as Mount Everest!

A neutron star (the tiny white dot in the middle) surrounded by the remnants of the supernova explosion that created it. Click to enlarge (Photo: NASA/Andrew Fruchter)

Neutrons stars have a “mass threshold”- if they take on too much mass, even the neutrons themselves will collapse. When two of these extremely dense neutron stars collide, the extra mass they add to one another causes their massive gravitational forces to tear each other apart.

They go into a blindingly-fast death spin, ejecting massive amount of material while merging into a doughnut like structure with a black hole at its center. The entire process takes just 20 milliseconds (that is 1/50th of a second, if you’re wondering).

Check out a simulation of the amazing phenomenon courtesy of NASA:

Now You Have No Excuse To Miss the Lyrid Meteor Shower Tonight

Once a year, Earth experiences the Lyrid meteor shower as it passes through a region of cosmic debris left behind by a comet known as Comet Thatcher, which orbits the sun once every 415 years leaving behind fresh debris each time.

This year, that’ll be happening tonight. The shower is expected to be at its peak in the early morning hours of Tuesday (4/22/14). If you’re in an area where the weather inhibits sky visibility, Space.com will be providing two webcasts of the event via NASA and slooh.com.

No word yet on whether or not you can wish on a shooting star you see via live stream…

How to find the lyrid meteors in the night sky
How to find the lyrid meteors in the night sky

Here’s some pictures of last year’s Lyrid meteor shower (click an image to enlarge):

 

View the full gallery from Space.com here.

 

 

Blowing the Top Off a Mountain to Build a Telescope So Big It Can See Signs of Life On Other Planets

In a few short weeks, engineers in the Chilean Coastal Ranges of the Andes Mountains in South America will be blowing off the top of Cerro Armazones.  Standing at 10,000 feet, it’s one of the tallest peaks in the region. Here’s Gird Hudepohl, the head engineer for the project:

“We will take about 80ft off the top of the mountain to create a plateau – and when we have done that, we will build the world’s biggest telescope there.”

Cerro Armazones, future site of the world’s largest telescope (Image: Wikimedia Commons)

The Coastal Ranges region is extremely arid, which increases visibility since water vapor in the air obscures a telescope’s vision (this is also why telescopes at high elevations have much better vision than those closer to sea level).

This isn’t Hudepohl’s first rodeo. He works for the European Southern Observatory and was in charge of the demolition of another nearby peak (Cerro Paranal) which is now home to one of the world’s most advanced observatories.

The observatory at Cerro Paranal is equipped with four VLTs (Very Large Telescopes), each the size of “a block of flats” and each equipped with an 8m wide primary mirror (thats more than 24 feet).

Here’s some pictures of the European Southern Observatory (click an image to enlarge):

The new telescope, however, will be bigger than all four of those VLTs combined. The E-ELT (European Extremely Large Telescope- they’re not very creative with the names obviously) will be equipped with a massive 39m (128ft) primary mirror made up 800 segments, each 1.4 meters in diameter but only a few centimeters thick. Each segment must be calibrated with microscopic precision for the telescope to function correctly.

When it’s finished (projected completion is 2025), the telescope will be housed in a 74m (~243ft) dome and weigh in at almost 3,000 tons. The project has a price tag of $1.34 billion.

Artist rendering of the completed E-ELT

The telescope is obviously extremely expensive, but the potential benefits it will provide are well worth it. Here’s Cambridge University astronomer Professor Gerry Gilmore explaining why the E-ELT will be such a major breakthrough:

“[Right now] we can see exoplanets but we cannot study them in detail because – from our distant perspective – they appear so close to their parent stars. However, the magnification which the E-ELT will provide will mean we will be able to look at them directly and clearly. In 15 years, we should have a picture of a planet around another star and that picture could show its surface changing colour just as Earth does as the seasons change – indicating that vegetation exists on that world. We will then have found alien life.”

Read the full story from The Guardian here.