Astronomy Online

Posts Tagged ‘astronomy interesting facts’

There must be a lot of astronomy facts right? Consider that there are somewhere around 1 x 10 ^22 stars in the universe, that’s a one followed by 22 zeros. Think about this, there are planets orbiting many of those stars. Then consider all the moons that orbit the planets, the comets and asteroids, the galaxies these stars form, the nebulae and black holes and everything else out there. It’s a lot to consider. This article, which presents astronomy facts, certainly won’t contain every astronomy fact. Walked is here, however, is interesting.

Let’s take a look at this subset of astronomy facts – the brightest stars as seen from Earth. Let’s ignore the sun, it’s too close. It’s so bright as seen from Earth that it washes out all the other stars in the sky during a phenomenon called “daylight”. Keep in mind that in the scale for the magnitudes given, lower numbers are brighter. The sun would be about -26.73, while the full moon is -12.6. And now to the top five.

#5 goes to Vega, Arabic for vulture. As seen from Earth its magnitude is .03. Just because a star looks brighter from Earth doesn’t mean it’s really brighter. Our sun, for example, appears brighter than any other star, even though it’s not one of the brightest in the universe.  That’s because it’s so close.

#4 goes to Rigel Kentaurus, or foot of the centaur. It’s about four light years from Earth with a magnitude of -.01.

At #3, remember this is set in stone as one of the many astronomy facts we have, is Arcturus. The name means guardian of the bear in Greek. This star is 37 light years from us.

#2 is Canopus. Of these top five Canopus, a Greek name for the pilot of the vessel Argo made famous in the stories about Jason and the Argonauts, is the brightest. But it’s 313 light years from Earth so it’s just second on this list as seen from Earth. It has a -.62 magnitude as seen by humans on this planet.

#1 is Sirius, meaning scorching in Greek. It’s also called the Dog Star because it’s the brightest star in the constellations Canis Major (the Big Dog). At only 9 light-years away from Earth it is the second closest in these top five. But from Earth it has a magnitude of -1.44. That makes it easily the brightest star as seen in the night sky.

There are many more astronomy facts out there. But consider it next time you see the stars in the night sky.