26 August 2011
Nearby Supernova Rocks Astronomical World
Posted by Dan Satterfield
The image above shows a Type Ia Supernova and it is very nearby at only 21 million light years (That’s nearby to astronomers you know ;)). It’s hard to express just how big this news is, because no other supernova has been seen this early after the star exploded, and telescopes around the world are now taking spectra of the light from it. Here’s one example of how big it is- The Hubble Space Telescope will be turned toward it on Friday or Saturday.
So what you say, that’s what it’s for!
Hubble is for doing observations that can only be done from space, and if you’re an astronomer who was lucky enough to get time on the telescope, it will be set months in advance! For NASA to even consider interrupting the schedule on 48 hours notice is the meteorological equivalent of three category 5 hurricanes approaching land, all at once! It’s the geological equivalent of the Japan tsunami/quake.
Why it’s so important.
Take a 100 watt light bulb outside and walk away from it. If you know it is a 100 watt bulb, you can tell just by looking about how far away it is in general. Now, get some good measuring equipment and you can tell almost exactly how far away it is. The math is very simple because you know how much light that 100 watt bulb is putting out, no matter how far away it is. The light-bulb in this case is called a standard candle.
Type 1 supernovas are standard candles!
They put out the same amount of light no matter how far away they are. Just measure how bright is looks and compare that with how bright it should be and plug the numbers into a simple equation and you know how far away it is! Having distance allows you to start getting even more info like the mass of the star, and how fast it is moving away from us due to the expansion of the universe. The fact that supernovas of the type Ia variety are standard candles allows astronomers to make measurements that can confirm theories on how fast the universe is expanding now and how fast it was expanding in the past.
Supernovas, have been (and still are) the holy grail in the search to explain what dark matter and dark energy (which make up most of the universe) are. The 1998 discovery that the expansion of the universe is increasing in speed, was made using supernova’s detected by telescopes.
Want to know more??
So do I.
Bad Astronomer Phil Plait can take over where I left off. You can also Google Adam Riess, High Z team, and read the book The 4% Universe.