According to modern theories, every object in the Universe today started out as a cloud of gas. These nebulae are building blocks, and using things like gravity and fusion, go on to create all the stars and planets, black holes, galaxies, globular clusters, and everything else in the cosmos. The zodiac sign Sagittarius is a centaur, raising up his bow ready to fire. Located between Ophiuchus and …Capricornus, Sagittarius contains the center of the Milky Way galaxy. Slightly up and to the right of his bow sits a tiny smudge of light, faintlySagittarius visible to the naked eye. That tiny smudge is the Lagoon Nebula, a cloud of gas measuring 110 light years across. Estimates put the Lagoon Nebula between 4,000 and 6,000 light years away from the Earth. Even though the nebula is visible to the naked eye, it is still very faint. For this reason ancient astronomers weren’t aware of its existence. It was discovered in 1747 by Guillaume Le Gentil. The nebula itself is composed mostly of hydrogen, and is classified as an emission nebula and an H II region. Many of the stars inside the Lagoon Nebula give off huge amounts of energy. This energy is put into the surrounding gas, causing it to ionize. We are able to see the nebula because the ionized gas that it is composed of gives off its own light. Inside the Lagoon Nebula astronomers are finding some very interesting structures. O-type stars are some of the rarest stars in the Universe. They are the biggest stars in our classification system, and are mostly hidden inside nebulae. These enormous stars have such strong gravity that fusion going on in their cores happens orders of magnitude faster than other stars. Where most stars last billions of years, O-type stars live brilliantly short lives measured in millions of years, putting out huge amounts of energy. — by Emil Ivanov http://buff.ly/1aVi5Ez Found at http://buff.ly/1aVi5EB

About these ads

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s