There are 88 constellations at present. There is a remarkable accumulations of bright stars, which are to be seen as impressive figures in the sky. These figures develop however only from the perspective of the earth's surface. Those stars, which belong to a constellation, are usually hundreds of light-years far from each other. If one could observe it from an another perspective ( side look - e.g. from the Virgo), then one would see to the fact that the stars are found to be apparently far away from each other. An apparent displacement of the observed stars is to be seen which is caused from an another point of view. 
 

CCD 

The astronomical photography developed to semiconduct detectors from the conventional photo plates. This is called CCD - Charge Coupled Devices. Under the use of computers one gets to undreamt of possibilities and good quality in the area astrophotography. 

Cosmology

is the science of the universe as an entire uniform. The instruments for this are mathematics, physics and the astronomy. The cosmologist cannot make comparisons since the universe is one entire large scale of structure. Even the long periods of the development in the universe cause problems.
 

Black holes 

are a forecast of general relativity theory by Albert Einsteins, their possible existence were already discussed by Laplace around 1800 . The force of gravity (attraction) are so strong in a black hole, that it gobbles up every matter. The space curvature is so strong that even light cannot escape any longer. The time ends here.  Within a black hole our usual conceptions of space and time collaps. Time transforms into space and space into time. Principally any body can transform itself into a black hole, however one would have to compress it enormously. If we would transform for example our sun into a black hole (which is fortunately in our present time such realizations hardly possible), then one would have to press it together from its present diameter of 1,4 million kilometers to 6 kilometers. According to the theory of the stellar evolution, black holes are the final stage of very massive blue stars. It is  therefore assumed that there are many black holes along the Milky Way, which weigh however typically only some solar mass. In some double star systems one could prove with large probability that such black holes exists. It is assumed that  extremely massive black holes are to be found in the central areas of many galaxies. Only by thus, very unusual characteristics and extremely high luminosities of some galaxy can be explained. In the case of the so-called quasars and Seyfert galaxies, the luminosity of the galaxy nucleus can achieve more than hundred times of the luminosity of all stars of the galaxy. 

These enormous energy quantities can be set free, if one would stream in gas in a black hole of one hundred million solar masses. Before the gas is swallowed by the black hole, 10% of its rest energy according to Einstein's famous formula E=mc2 can be transformed into energy.. 

The energy is several times higher per gramm mass according to that what the fusion reactor can archieve inside the sun. Since black holes are active only for a small fraction of their lifetime in the galaxy nuclei,  they absorb and produce high luminosity gas from their environments, there still exist a multiple of galaxies with passive black holes besides those which are less active. 

An extreme hypothesis means that possibly even all eliptical galaxies and spiral galaxies with Bulges contain a massive black hole. In co-operation with an American astronomers team, members of the university of Munic have searched dynamic notes over the existence of such extremely massive black holes in passive close galaxy nuclei. Black holes are proven to exist in result of the movement of the stars in their direct proximity. Due to the extreme attraction of a black hole , the nearer the stars approach the hole , the faster they move. 
One can determine a black hole successfully only if sufficient high spatial resolutions are archieved. For this reason observations with the Hubble space Telescope and the Canada France Hawaii Telescope were carried out. These two telescopes provide at present the highest image quality and spatial resolution. Through these investigations, it was found out that even normal and passive galaxies can contain massive black holes. The small compact eliptic galaxy M 32, a companion of the Andromeda Galaxy is an example of the galaxy which probably contains a black hole of approximately one million solar masses. Even Andromeda probably accommodates a black hole of some ten million sun masses. 

The S0-Galaxie NGC 3115, which is close with harmless appearence is an extreme case. An enormouse black hole of a billion solar masses is to be found in its core. Indeed it is suggested that each galaxy contains a black hole in the center, the mass of the black holes is probably proportional to that of the galaxy mass. This relatively typical galaxy cluster contains approximately hundred elliptical, S0- and spiral galaxies and over thousand dwarf galaxies. As far as that can be determined, the total number of galaxies observable in the universe , amounts to more than one billion galaxies. The light, which we receive from the furthest  galaxies, was sent more than 12 billion years ago, only about two billion years after the Big Bang. 
 
 

Black hole 
meant that very high attraction (intense high gravitation effects) exists in the object, from which nothing - not even light - can escape. Therefore they look black. They are the end product of the development of a sun, which possessed more than 5 solar masses. In fact Black holes are stars with enormous mass in the last stage of their existence. Pierre La Place predicted the existence of black holes in the 18. century. His theory was then used as basic of quantum mechanics. 

Karl Schwarzschmidt supplied 1916 with the mathematical bases for the theory of the black holes. However when a star has used its combustibles, a gravitational collapse occurs. A sun with more than 5 sun masses determines  its existence with supernova - explosion and turns sometimes to a black hole, which indicates an inconceivable density on smallest space. In the proximity of black holes, the time passes more slowly than comparatively on the earth. They distort time and space (- - > see space-time curvature ). Our sun does not possess 5 solar masses and will die in approximately 4.500.000.000 years.This means the end of the earth and its existence. 
Would an airplane fly in the black hole, it would happen to enter again a universe through  a Hypetunnel (wormhole) with a white hole (the opposite part of the black hole --> only matter donor). Another possibility is that the airplane would be pressed together to billions of cubicmillimeter through this tremendous gravitation during its entrance. 
Black or white holes are  usually to be found in connection with a double star, which are  the sources of x-ray. 
All bodies, which are attracted in the core are compressed to minimum volume that possess  a very high specific weight. 
In a theory, it means that the attracted bodies could be shifted for example  into a parallel universe. Even the connection to another black hole at astronomical distance ( Hypetunnel (wormhole)) is not improbable. 
Black holes can also be developped  from large neutron stars. In this case the word star is used for sun. They do not send any electromagnetic radiation - and can therefore not be "seen". The first black hole was found at the beginning of 1970 in the source of x-ray double sun Cygnus X-1. Steven Hawking explanations says that even black holes radiates. 
 

The local group 

The Andromeda Galaxy is found at a distance of 2 million light-years away from the Milky Way. All other galaxies are dwarf galaxies and companions of these main galaxies. Beside our Milky Way, there are further 30 galaxies  (Andromedanebel M31 M33 etc. - which belong to the local group)   among them only 3 spiral galaxies - they are the Milky Way -  the Andromeda nebula (it is not  a nebula - but a galaxy) and the Triangulum galaxy. All others are either irregular or dwarf elipse galaxies, which move around the large spiral galaxies. 
 
 

The Virgo heap is one of the next galaxy clusters. Its distance amounts to approximately 50 million light-years. The galaxies are so close in the center of the Virgo heap,  that it often comes to collisions or near-miss.  These Spiral galaxies have a very a small chance of survival. 
 
 

All natural punctiform source of light in the sky, seen in daily life by naked eyes, are called stars. But the term star is reserved  for other stars in the astronomy. Thus one of the most important realizations of the modern astronomy is expressed, in other words, it means that almost every lights seen in the night sky are distant suns. 

Solar system-traditionally: Our system consist of the sun, the nine planets and their moons, the comets, asteroids and meteoroids. More generally (not officially): A solar system is a bound system through gravitation which consists of single , double or multiple star and also lighter bodies bounded to it. This definition covers our solar system with the sun, it is a single star. Star is used in the sense of modern astrophysics as synonym for sun since the terms double sun, multiple sun  are not so common. 

 
 

Planet 

In the antiquity is the planet a wanderer, i.e. in the course of the days it noticeably change its position compared to fixed stars. At that time were  Mercury, Venus, Earth, Mars, Jupiter and Saturn well known. According to the antique definition , the sun and the moon are also to be taken into account. With the discovery of other planets (Uranus, Neptun and Pluto) of our sun as well as the special-solar planets, the term would have to be redefined. e.g. as follows: The planets are bodies, which circle another body with more than 1.6E29 kg (0,08 solar masses) mass and possesss itself a mass between 1E23 kg (Pluto) and 2E28 kg (10x Jupiter). Lighter bodies would be then the Asteroids, heavier bodies would be  the brown dwarves. 
 

Pole reversal 
The magnetic field around the earth begins in 100 km height and reaches approximately 50000 km in the universe. It is a protection against the solar wind, which also causes the polar light. A reversal pole of the magnetic field take place every 100,000 years. The reasons  are completely unclear. 
 

Radiations in space 
These are the following:  Electromagnetic waves are divided into wavelength - in the electromagnetic spectrum: 
Radiowaves wavelength 1 m or more 
Microwaves wavelength a few centimeter 
Infrared radiation wavelength of 0.0001 centimeters 
visible light wavelength of 0.000005 centimeters 
Ultraviolet radiation wavelength still shorter than light 
X-ray - wavelength still shorter than light 
Gamma-ray wavelength still more shorter than light 
 

Units 
1 Megaparsec MPC = 1000000PC = 3260000 light-years 
1 Parsec PC = 3.26 light-years = 30000 billion km 
1 Kiloparsec kpc = 1000 PC 
1 light-year Lj (Lightyear) is the distance, at which light beams take to cover in one year,  thus 9400 billion km is a Lj. The light moves at 299792,458 km/second in the vacuum. 
Astronomical units:1 AE = 149,600,000 km 

The Andromedanebula - which is the next galaxy and found to be 2.2 million light-years far away from us, that are 675 kpc.
 
 

Planetary nebula (fog) 

The term is developped historically, since many smaller planetary nebulas ressemble somehow like the sight of a pale lighting disc, when observed through the telescope. Therefore the term does not have to do anything with planets. At the end of its life, a massive star, lose parts of its mass like expansion of a gas bubble. All what remains inside the inner part is a hot white dwarf (100000 degrees). The gas bubbles fluoresces by its ultraviolet light. The gas bubbles shines in individual emission lines. The Andromedanebula is a historically grown name. Originally it is meant that, a fog is formed through out of gas and dust. 
 
 
 

Solar eclipse. 

Only the corona of the sun can be seen by the perspective of the earth while a solar eclipse occurs - the sun disk is covered completelly by the moon.  If the diameter of the sun or the moon would be smaller or larger,  or would be the distance of the moon or sun to the earth smaller or larger  - it would not come to the "coincidence", which covers the sun disk exactly. This is not a coincidence. 
 
 

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