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1) A supernova is an explosion, triggered by the collapse and explosion of a massive star. There are two types of supernova explosion in the universe, called Type I and Type II. The remains of the core of a star that has gone supernova is a neutron star. These stars give off radio waves called pulsars. When a huge star goes supernova, the gravity of the core becomes so strong that even light cannot escape it. This is called a Black hole.
On occasion, throughout the centuries, astronomers have been puzzled by the appearance of, as they phrased it, new stars in the sky. For instance, in July 1054 AD, Chinese astronomers noted the appearance of a \'\'guest star\'\' (as they called it) in the constellation Taurus. The guest star was visible in broad daylight for three weeks, and was visible at night for two years before it faded into invisibility.
Astronomers also study supernovae because they are rare, luminous, and fairly brief events. There are only about one per century in our galaxy.
2) Normal forces give us the sensation of having weight. If we remove the supporting force, we have the sensation of “apparent weightlessness.” For example, a skydiver feels weightless before opening the parachute and in and the unlikely event of an elevator breaking loose, you would also experience weightlessness. Certain amusement park rides are designed to remove the supporting force and induce a feeling of weightlessness.
Galileo correctly concluded that in free fall, all objects must fall at the same rate. While in orbit our astronauts are constantly falling. Since everything around them is also falling and everything falls at the same rate, they have a continuing experience of weightlessness.
Some of the very real effects to the human body of this "apparent weightlessness" include:1. Loss of bone mass (similar to osteoporosis)
2. Reduced total blood volume, particularly loss of red blood cells
3. Giddy, light-headed feeling
4. Space sickness with nausea and vomiting
5. Decrease of heart size
6. Nasal congestion
7. Muscle weakness
3) To determine the movement of a star through the universe, scientists use a method called red shift. There are 3 different types of red shift and two are used to find the movement of stars. The Doppler Red shift results from the relative motion of the light emitting object and the observer. If the source of light is moving away from you then the wavelength of the light is stretched out, i.e., the light is shifted towards the red. These effects, individually called the blue shift, and the red shift are together known as Doppler shifts.
The other red shift used to find the motion of stars is the Cosmological Red shift. This is a red shift caused by the expansion of space. The wavelength of light increases as it traverses the expanding universe between its point of emission and its point of detection by the same amount that space has expanded during the crossing time.
4) Sunspots are regions on the solar surface that appear dark because they are cooler than the surrounding photosphere. They are believed to be caused by intense magnetic fields interfering with the bubbles of hot gas. They are only dark in a relative sense; a sunspot removed from the bright background of the Sun would glow quite brightly. The largest sunspots observed have had diameters of about 50,000 km, which makes them large enough to be seen with the naked eye. Sunspots often come in groups with as many as 100 in a group, though sunspot groups with more than about 10 are relatively rare. Sunspots develop and persist for periods ranging from hours to months, and are carried around the surface of the Sun by its rotation.
Solar flares emit radiation that includes x-rays and ultraviolet rays, charged particles called protons and electrons, and powerful particles with no electric charge, called neutrons. This radiation surge may damage electrical power systems, interfere with telecommunications, wreck high-tech ship navigation systems, harm an astronaut in space, or create the spectacular Northern and Southern lights, aurora.
5) The Big Bang Theory is the dominant scientific theory about the origin of the universe. It states that the universe was created between 10 and 20 billion years ago from the random, cosmic explosion of a subatomic ball that hurled matter and energy
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Physical cosmology, Galaxy, Supernova, Astronomy, Redshift, Big Bang, Star, European Southern Observatory, Cosmic microwave background, Universe, Metric expansion of space, Hubble Space Telescope
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