Mega parsec (Mpc) is a unit that consists of 1 million parsec, where 1 parsec is equal to 3.26 light years. Distance indicators are used to measure distances of objects brighter than Cepheid stars. Hubble’s Law is the relationship between the distances of galaxies; the further away the galaxy is the faster its moving. Spiral Galaxy is where there is a central hub surrounded by a disk of stars, gas and dust in a spiral pattern. Elliptical Galaxy is a round ball shape galaxy which consisting of almost a trillion stars in them. Irregular Galaxies are small galaxies that have no fixed shape. Barred Spiral Galaxy is a galaxy that has a nucleus which has a shape of a bar from which the spirals arms extend. Star Burst Galaxy is galaxies that are undergoing
It is easy to flip to the index of an astronomy textbook to discover that, say, the Sun lies 150 million kilometers away from Earth. It is far more difficult (if not impossible), however, to picture this distance in the human mind. In this exercise, we will learn to access the often unpalatable distances encountered in astronomy by simply scaling the huge distances to more recognizable, pedestrian numbers. So long as every distance within the system of interest is scaled by the same factor, we retain the meaningful information about relative distances between objects.
Just under seven years ago, astronomers using the Hubble space telescope presented results they hoped would help answer one of the most contentious issues in astronomy of the 20th century – the question of the distance scale of the universe. But there was some unease when the result was announced. According to the report, other galaxies were close enough that, extrapolating backwards from their current rate of recession and making adjustments for the influence of gravity, they all would have been together (that is, the Big Bang would have occurred) as recently as 8 billion years ago. Unfortunately, there was strong evidence already in place that some stars were at least 12-15
b. The farther away a galaxy is the faster it appears to be moving away.
The farther away a star is, the less its parallax. The light year is a unit used to express stellar distance, which is the distance light travels in a year, which is approximately 9.5 trillion kilometers (5.8 trillion miles). The parallax angles are very small. Proxima Centauri is the parallax angle nearest to the star. It is less than one second or arc, which equals 1/3600 of a degree. A human finger is roughly 1 degree wide. The distances to stars are so large that conventional units such as kilometers or astronomical units are often too cumbersome to use.
R* is the average rate of formation for suitable stars. A suitable star must have an appropriate temperature (i.e. not too hot or cold). It is possible to use the average rate for the galaxy. This can get a bit hazy, as the
1. Describe how MinuteClinic puts the following promotion strategies to work for them: stressing tangible cues, using personal information sources, creating a strong organizational image, and engaging in post-purchase communication. What else could they try?
It is easy to flip to the index of an astronomy textbook to discover that, say, the Sun lies 150 million kilometers away from Earth. It is far more difficult (if not impossible), however, to picture this distance in our mind. In this exercise, we will learn to access the often unpalatable distances encountered in astronomy by simply scaling the huge distances to more recognizable, familiar numbers. So long as every distance within the system of interest is scaled by the same
Scientists using NASA's Hubble Space Telescope have discovered that the i halo of gas enveloping the Andromeda galaxy, our nearest massive neighbor, is about six times larger and 1,000 times more massive than previously measured. The dark, nearly invisible halo stretches about a million light-years from its host galaxy, halfway to our own Milky Way galaxy. One of the most common types of galaxies in the universe.
12. From a humans point of view the galaxies are all moving away from earth.
There are various methods of determining the distances of stars. Some of them include the variable stars theory, parallax method, use of color and the expanding universe theory, just to mention a few. The method that is the most common and can easily be explained is parallax, which is well explained through illustration. When one holds an object high up front so that it blocks your front view and close one eye in different turns, the item appears to move in relation to the item in front. When both eyes are open one may get an idea of how far the object may be and the distance is obtained by the length of direction change, and this theory is known as parallax.
Out of the four options, light-years measure the greatest distance. The distance in the other units would be too large. It is easier to read measurements when using a unit that can scale a larger area.
The only difference is that instead of sound waves, it is light waves that are moving away. In 1912 when Vesto Slipher discovered that all objects in the sky were moving away from Earth. (Cain). Back in 1912, it it was thought that these objects were in the Milky Way, over a century later, humanity knows that these objects are galaxies and they are thousands/millions of light years away. Twelve years later in 1924, Edwin Hubble discovered that these stars were actually outside the galaxy.
Our sun is halfway through its life cycle and based on the studies of the stars, when it reaches the last stages of its life it will go supernova destroying Earth, but that won’t happen in about 5 billion years.
A galaxy, also called a nebula, consists of billions of stars, interstellar gas, dust, and dark matter which are all bound to form a massive cloud in which we live in. Although it cannot be very well explained, dark matter makes up at least 90% of a galaxy’s mass.
This observation means that it has taken every galaxy the same amount of time to move from a starting position to its current position. This observation is called "Hubble's Law," named after Edwin Hubble (1889-1953) who discovered this in 1929. Edwin Hubble’s evidence supports the expansion of the universe and suggests that the universe was once compacted. Third, if the universe was insanely hot as the Big Bang suggests, scientists should be able to find some of this heat left over. In 1965, Arno Penzias and Robert Wilson discovered a 2.725 degree Kelvin Cosmic Microwave Background radiation which infuses the observable universe. This is thought to be the remnant that scientists were looking for. Finally, the discovery of great amounts of Helium and Hydrogen lead to support the Big Bang Theory. (LaRocco)