adapted from What Is a Supernova?
by NASA
A supernova is the explosion of a star. It is the largest explosion that takes place in space.
Where Supernovas Take Place
Supernovas are often seen in other galaxies. But supernovas are difficult to see in our own Milky Way galaxy because dust blocks our view. In 1604, Johannes Kepler discovered the last observed supernova in the Milky Way. NASA's Chandra telescope discovered the remains of a more recent supernova. It exploded in the Milky Way more than a hundred years ago.
How Supernovas Form
A supernova happens where there is a change in the core, or center, of a star. This change can occur in two different ways. The first type of supernova happens in binary star systems. Binary stars are two stars that orbit the same point. One of the stars steals matter from its companion star. Eventually, that star accumulates too much matter. Having too much matter causes the star to explode, resulting in a supernova. The second type of supernova occurs at the end of a star's lifetime. As the star runs out of fuel, some of its mass flows into its core. Eventually, the core is so heavy that it cannot withstand its own gravitational force. The core collapses, which results in the giant explosion of a supernova.
Why Scientists Study Supernovas
A supernova burns for only a short period of time, but it can tell scientists a lot about the universe. One kind of supernova has shown scientists that we live in an expanding universe. Scientists also have determined that supernovas play a key role in distributing elements throughout the universe. When the star explodes, it shoots elements and debris into space. In fact, many of the elements we find here on Earth are actually made in the core of stars.
How NASA Scientists Look for Supernovas
NASA scientists use different types of telescopes to look for and study supernovas. Some telescopes are used to observe light from the explosion. Others record data from the X-rays and gamma rays that are also produced. Both NASA's Hubble Space Telescope and Chandra X-ray Observatory have captured images of supernovas.
What You Can Do to Help
You do not have to be a scientist, or even have a telescope, to hunt for supernovas. For example, in 2008 a teenager discovered a supernova. Then in January 2011, a 10-year-old girl from Canada discovered a supernova while looking at night sky images on her computer. The images, taken by an amateur astronomer, just happened to include a supernova. With some practice and the right equipment, you could find the next supernova.
7
Which sentence from the passage best supports the idea that supernovas are rarely seen in the Milky Way Galaxy?
A.
But supernovas are difficult to see in our own Milky Way Galaxy because dust blocks our view.
B.
For example, in 2008 a teenager discovered a supernova.
C.
A supernova happens where there is a change in the core, or center, of a star.
D.
In 1604, Johannes Kepler discovered the last observed supernova in the Milky Way.
1 answer
1 answer