You may have seen a picture of a nebula before without actually knowing the term. So, what exactly is a nebula? A nebula is a huge cloud of combined gas and dust in space. They are sometimes considered nurseries, because oftentimes they are the location where stars are created and born.
Nebulae, which is the plural form more than one of nebula, form when gas, like hydrogen and helium, as well as molecules, particles, ions, and electrons are pulled together by gravity. Some of the gas and dust particles group together to create common regions that have similar densities.
In areas that become more dense, stars can form out of the collapsing material. There are a few different kinds of nebula formations. Many nebulae have no clear beginning or end, and no clear boundaries. It is illuminated by a pulsar which was created by the supernova. Nebulae are often the sites of star formation. In fact, all stars, planets, and solar systems are formed from nebulae.
A nebula may lie undisturbed for many millions or billions of years as it waits for just the right conditions. Eventually, the gravity from a passing star or the shock wave from a nearby supernova explosion may cause swirls and ripples within the cloud. Matter begins to coalesce into clumps and grow in size.
As these clumps get larger, their gravity increases. Gravity continues to pull in matter from the nebula until one or more of the clumps reach critical mass. The clumps are forming protostars. As gravity squeezes even tighter, the core temperature eventually reaches 18 million degrees. At this point, nuclear fusion begins and a star is born. The solar wind from the star will eventually blow away all of the excess dust and gas. Sometimes other smaller clumps of matter around the star may form planets.
This is the beginning of a new solar system. Several nebulae have been found to be stellar nurseries. The Eagle Nebula, and the Orion Nebula are both sites of active star formation. There are a few nebulae that can be seen with the naked eye and many more that can be detected with a good pair of binoculars. A telescope is required to bring our fine details.
Unfortunately, the human eye is not sensitive enough to bring out the rich colors of most nebulae. It is the photograph that does the most justice to these incredible objects. Until recently, time exposures on film were the best way to bring a nebula's true colors. Today, digital photography has simplified the process. New tools like the Hubble space telescope are giving us views of nebulae that have never been seen before. Areas of active star formation have been identified in many galaxies that were once thought to be inert.
Perhaps the most well known nebulae is the Orion Nebula, also known as M It is one of the very few that can be seen with the naked eye. It is a bright emission nebula over 30 light-years in diameter. The nebula is illuminated by a group of stars at its center known as the trapezium. Another popular favorite is the Lagoon Nebula, M8. It is much larger than the Orion Nebula, reaching over light-years across the heavens. The Trifid Nebula, M20, is one of the most colorful.
This reflection nebula contains a combination of elements that render it in rich hues of red, blue, and pink. The video is a great introduction into the intersection between astrophotography and astrophysics — describing how the beautiful images we see are the results of different physical processes in the distant Universe, and how we can share this knowledge through the correct classification of labels used when describing images, filters, and objects.
But sometimes I think they are not able to exploit fully what they see on those outstanding images. That is why I prepared this video the first in a series combining Astrophysics and amateur Astronomy , to let them and the general public understand that the colours have a physical meaning.
He is a recognised expert in the study of how the gas is converted into stars in nearby galaxies and how this affects galaxy evolution. He also provides support for visiting astronomers to the AAT. He is a globally-recognised science communicator, with visibility in Spanish and Australian printed, broadcast, and social media one of the Top most-followed astrophysicists in Twitter. He is also a passionate amateur astronomer that uses his own equipment for capturing the beauty of the Cosmos.
Amateur Astronomy Astrophotography Astrophysics Nebulae.
0コメント