Sunday, January 31, 2016

Black Holes

Black Holes

Black holes are an object in space that contains the density thought to be infinite enough to create a gravitational field great that light cannot escape it's gravity beyond a certain point known as the even horizon.

Black holes are formed by a hyper giant star collapsing in on itself. This is when the radiation force of a star is less than of that of it's gravitational force thus causing the core to allow the star to collapse in on itself or implode. When a hyper giant implodes, sometimes it can have a very high density and become a black hole. These objects can hold massive amounts of other bodies around them. In spiral galaxies, these black holes are known to be located at the center and they contain stars in which they orbit around the black hole. These black holes usually have millions to trillions of stars orbiting them.

Black holes can also destroy objects atomically. When a body gets too close to the black hole, the gravity by the black hole will get stronger relative to the body getting closer to the black hole and the black hole will either rip it apart from atom to atom or it will become super heated plasmatic material. Depending on the size of the black hole and the mass, these can/will occur. 

Though, these black holes sound like they don't have a death cycle, they do, but it hasn't been achieved yet. Hawking Radiation is the idea, from Stephen Hawking, that quantum field theory can explain that a black hole can lose energy over time and shrink and then eventually be spread out into cloud of material rather than a dense object. They have used the center of the galaxy's black hole, Sagittarius A, to observe this idea and have looked at the magnetic field of the black hole and the first photo every released was in early 2016. This is a great initial result stating that black holes do emit radiation with the studies done previously can conclude Hawking Radiation to be a real thing.

Saturday, January 23, 2016

Our Solar System



Our Solar System


     Our solar system is composed of many materials and planets. The Sun is the main component of our solar system and makes up 99.84% of our solar mass. On the other hand, the gas giants make up 90% of the .14% left of our solar system and the terrestrial planets make up 0.02% (along with the other materials found).

     Our solar system is unique in that Earth is the only known planet to have life on it. Other than that, it is unique to it's signature of planets. Our planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune, is what makes up the planetary orbitals around our Star called the Sun (Sol).

     The terrestrial planets (non gas giants) are composed of mostly iron and silicates. Only Mars and Earth are known to have a small percentage of water on them compared to Mercury and Venus, in which Mercury is too close to the Sun and too hot to retain water, Venus is too hot due to the Green house effect, it cannot retain liquid water. Mercury has a surface temperature at night side -280*F and 800*F on the side facing the sun. It has a 7* elliptic orbit and has an 88 Earth-day orbital period. Venus is known to be in the habitable zone of our star, but since the thick atmosphere traps in most of the heat on its surface, it retains a heat of 750*F. The atmosphere has very reflective clouds of sulfuric acid, making it difficult to see the surface with visible light from outside of it. It has a orbital period of 224 days. Earth is the most unique planet in our solar system in that it contains life, a magnetic field which is created from tectonic activity and has a hydrosphere with life inside of it. Mars could have had life on it once, as predicted by the surface of it showing erosion scars on the surface.

     Our gas giants, Jupiter being the biggest, is made mostly of hydrogen and are said to have an iron core due to how our other planets where created. These planets formed from the outside of the terrestrial planets because they were far enough to have the gas be cool enough to collect in large amounts. The story is the same with the other gas giants, they all are said to contain rings, but Saturn's is the most relevant out of the bunch.

Saturday, January 16, 2016

Types of Stars in the Milky Way galaxy

Types of Stars in the Milky Way galaxy


     There are estimated about 100 billion to 400 billion according to solar mass as estimated by scientists who believe that because the Milky way is 100 billion solar masses, there should be around 100 billion that average out, or go by the reason that most of the stars are yellow dwarfs or red dwarfs so there could be more than 100 billion with estimation.

     Our sun is a yellow dwarf star, our star is very important to Earth but not important compared to the interesting stars found in our galaxy. A yellow dwarf star has 80%-100% of the star, sol, our sun's, mass. This is one of the most common stars in the Milky Way galaxy. The most common, however, are the red dwarf stars. They are estimated to make up 80% of our galaxy, though, because of their low luminosity, it is hard to see them with the human eye on Earth. In 1990, the Hubble space telescope was launched into orbit around Earth at a low altitude. This telescope has contributed to the findings of the red dwarf stars that make up our galaxy by having instruments being able to detect multiple waves of the electromagnetic spectrum. According to NASA, the space telescope has made 1.2 million observations, some of which, are very impressive.

     The biggest star observed in our galaxy is UY Scuti. It is part of the Scutum constellation and it is about 2.4 billion kilometers ( 1,708 solar radii, 15.6 AU, 1.5 billion miles) in diameter with a volume of about 5 billion times that of our sun. It is about 9,500 lightyears (2.9 kiloparsecs) away from our Earth. If it were placed in our solar system where are Sun is, it is said that it would engulf everything up to Jupiter. Though this is the biggest star in our galaxy, there are more interesting things that exist within our galaxy. Imagine, having a magnetic iron bar and the bar would spin at an angle and the speed of the spin would be around 2000 revolutions per second while floating in the air. There is such a thing that exists within our galaxy. These are called pulsars. Pulsars are a neutron star that spin very quickly, about thousands of times per second and at their magnetic poles, shoot out particles of electromagnetic radiation. Neutron stars, by themselves, are about 20km in diameter on average with the mass of 1.4 times that of our Sun. The objects are so dense that if you were to stand on a Neutron Star, you would weigh 2 x 10 to the 11th power times more. Pulsars are a special kind of neutron stars, as to how a square is a special type of rectangle.

     There are stars, though, that have are so bright, that if Earth where the same distance from the Sun (1 AU) but had the Sun replaced by another, everyone, including people on the dark side, would be blinded by the light. There are many stars like this, but non other like R136a1. This is a Wolf-Rayet star, or stars that emit very high levels of ionized helium, nitrogen or carbon. This star has the most mass out of any star observed in our galaxy with 265 times the mass of our Sun. It is -91,200 solar luminosity ( our sun is -27.74). Solar luminosity is measured by how bright a star is. The lower the number is, the more visible on Earth it is. The higher the number, the less visible on Earth the star is. It is also the hottest star, at 50,000K (49726.85 C, or 89540.33 F). This is the most massive star in our galaxy (Do not confuse mass with density). If you were to stand on the star, you would weigh 10 times the weight you do on Earth. This is a very young star and is considered a main sequence star. This star is very rare and is a great find to look for during the night.

Friday, January 8, 2016

Nebulae

Astronomical Discoveries #1 - Nebulae


a.     This picture above is the Eta Carina Nebula. This is a formation made by a star that has reached the end of it's life cycle, in which it will either go into nova, the process in which small stars release it's outer "shell" of materials, supernova, when bigger stars collapse in its own gravity and release all of it's material, or a hypernova, in which huge stars collapse into itself and produces gamma rays from the release. It is said that it could make a pulsar or a black hole.

1.     What is a nova?
         A nova is the ejection of gas and materials from a star due to the star's inability to support itself from the forces of gravity. Radiation forces from the star from fusion in the star push outward while gravity pulls inward. When the elements inside of the star start fusing into heavier elements is when the radiation force is weaker than the gravitational force (i.e. H -> He -> Li and etc.).

2.     What is a nebula?
        A nebula is a collection of the released gas and material. It is said known that our solar system was made from a nebula made by a star that had gone supernova, not nova or hypernova. The Eta Carina Nebula will have new stars and possibly new systems from the nebula.

3.     What will happen to our solar system?
        Our star is considered a yellow dwarf star, it is a small star compared to other stars like UY Scuti and Betelgeuse. Our star will expand out and engulf the inner planets with the probability of Earth being in that list. It will not "explode", the outer shell of the star will eject it's material and it will spread outward in the outer solar system. What will be left will be a white dwarf with the mass of half our sun. If the Earth does survive, it will lose it's original orbit and be in the outer solar system or not in the system from it's velocity.