Tag Archives: Wavelength

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.

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Mind-Blowing Video: What Don’t You See When You Look at the Sun?

The Sun is composed of a number of different compounds and elements which exist at different temperatures and therefore emit radiation with different wavelengths (this is explained in more depth below the video).

All of the light we see with our eyes is electromagnetic radiation that falls within the “visible spectrum”, meaning that the photons, or light particles, have a wavelength between 400 and 700 nanometers (a nanometer is 1 billionth of a meter).

The range of wavelengths within the sun in 250-2500 nanometers. This video shows you all of the the other forms of radiation that our eyes can’t see.

Since all photons travel at the speed of light (roughly 30million m/s or 670,616,629mph), a photon with a longer wavelength must have a shorter frequency (how many waves pass a point in a given time).

For example, imagine you have two waves traveling past a line you have drawn: one wave that has a wavelength of one meter and another that has a wavelength of two meters. If they travel at the same speed, two of the one-meter waves will pass your line in the time it takes one full two-meter wave to pass it, so we say the shorter one has twice the frequency. In fact, multiplying the wavelength and frequency of any photon will give you the speed of light.

Frequency and temperature are directly proportional so different materials release photons with different frequencies, depending on how hot the material is. Here’s a great chart that shows the relationships between wavelength, frequency and temperature. Click to see full size.

For more information, visit the project’s page on NASA’s website by clicking the image below.