The Horsehead Nebula, aka Barnard 33. It’s about 1500 light years from Earth. If you want to visit, I suggest leaving now to avoid the weekend rush.
A flare star is a variable star that can undergo unpredictable dramatic increases in brightness for a few minutes. It is believed that the flares on flare stars are analogous to solar flares in that they are due to magnetic reconnection in the atmospheres of the stars. The brightness increase is across the spectrum, from X rays to radio waves. Most flare stars are dim red dwarfs, although recent research indicates that less massive brown dwarfs might also be capable of flaring.
This movie taken by NASA’S Galaxy Evolution Explorer shows one of the largest flares, or star eruptions, ever recorded at ultraviolet wavelengths. The star, called GJ 3685A, just happened to be in the Galaxy Evolution Explorer’s field of view while the telescope was busy observing galaxies. As the movie demonstrates, the seemingly serene star suddenly exploded once, then even more intensely a second time, pouring out in total about one million times more energy than a typical flare from our Sun.
Image credit: NASA/JPL-Caltech
Supernova explosion (artist’s impression)
One of the most massive cosmic explosive events in the universe is a supernova. A supernova is the violent death of a luminous supergiant star. These blindingly bright star bursts occur at the end of a star’s lifetime, when its nuclear fuel is exhausted and it is no longer supported by the release of nuclear energy.
If the star is particularly massive, then its core will collapse and in so doing will release a huge amount of energy. This will cause a blast wave that ejects the star’s envelope into interstellar space. Astronomers originally classified supernovae into two “types”, I and II. Type I had no hydrogen emission lines in their spectra whereas Type II exhibited hydrogen emission lines. Later it was realized that there were in fact three quite distinct Type I supernovae, now labelled Type Ia, Type Ib and Type Ic.
Supernovae play a fundamental role in a great cosmic recycling program. We believe that almost all of the elements in the Universe that are heavier than hydrogen and helium are created either in the centres of stars during their lifetimes or in the supernova explosions that mark the demise of larger stars.
Image Credit: freeara
The term meteor actually refers to the streak of light caused by a piece of space debris burning up in the atmosphere. The pieces of debris are called meteoroids, and remnants of the debris that reach Earth’s surface (or another planet’s) are called meteorites.
When a small meteoroid enters the Earth’s atmosphere, it goes from traveling through a vacuum to traveling through air. Traveling through a vacuum is effortless — it takes no energy. Traveling through air is another story:
Earth’s atmosphere is full of matter, which creates a great deal of friction on a traveling object. When the meteoroid hits the atmosphere, the air in front of it compresses incredibly quickly. This causes friction and it generates enough heat to raise the meteoroid’s surface to its boiling point, so the meteoroid is vaporized, layer by layer.
The friction breaks the molecules of both the meteoroid material and the atmosphere into glowing ionized particles, which then recombine, releasing light energy to form a bright “tail.”