1.
What is a Star?
Correct Answer
B. A very big collection of matter,mostly gas compressed to incredible pressure and heat by gravity.
Explanation
A star is a very big collection of matter, mostly gas, that is compressed to incredible pressure and heat by gravity. This compression causes the gas to undergo nuclear fusion, releasing energy in the form of light and heat. The immense pressure and heat in the core of a star create the conditions necessary for nuclear reactions to occur, primarily the fusion of hydrogen atoms to form helium. This process is what powers a star and allows it to emit light and heat.
2.
What does a star form from? (first stage)
Correct Answer
C. A stellar nebula
Explanation
A star forms from a stellar nebula. A stellar nebula is a cloud of gas and dust in space, composed mostly of hydrogen and helium. Gravity causes the nebula to collapse and condense, creating a dense core called a protostar. As the protostar continues to gather mass, it heats up and begins nuclear fusion, becoming a star. A black hole, quasar, and supernova are all different astronomical phenomena that do not directly relate to the formation of a star.
3.
What is the red shift?
Correct Answer
B. Galaxies and stars are moving away from us. (The universe is expanding)
Explanation
The red shift refers to the phenomenon where galaxies and stars appear to be moving away from us, indicating that the universe is expanding. This is supported by the observation that the light emitted by these celestial objects is shifted towards longer wavelengths, towards the red end of the spectrum. This is a key piece of evidence for the Big Bang theory, which suggests that the universe originated from a single point and has been expanding ever since.
4.
What is a Pulsar?
Correct Answer
A. A highly magnetic, rotating star that releases a beam of radiation.
Explanation
A pulsar is a highly magnetic, rotating star that releases a beam of radiation. Pulsars are formed from the remnants of massive stars that have exploded as supernovae. The intense magnetic field of a pulsar causes it to emit beams of electromagnetic radiation, which can be observed as regular pulses of light. These pulses are often detected in the radio wavelength, but can also be observed in other forms of energy such as X-rays and gamma rays. Pulsars are important astronomical objects as they provide valuable insights into the physics of extreme conditions and the behavior of matter under intense gravitational fields.
5.
Why is a black hole called "black"?
Correct Answer
C. Because it absorbs all the light that hits it, reflecting nothing.
Explanation
A black hole is called "black" because it absorbs all the light that hits it, reflecting nothing. This means that no light can escape from a black hole, making it appear black.
6.
What is a White Dwarf Star?
Correct Answer
A. A faint star of enormous density.
Explanation
A white dwarf star is a faint star of enormous density. This means that it is a star that appears dim but has a very high mass packed into a small volume. White dwarfs are the remnants of stars that have exhausted their nuclear fuel and collapsed under their own gravity. The collapse causes the star to become incredibly dense, with the mass of the star compressed into a size similar to that of Earth. Despite their small size, white dwarfs can still be extremely hot and luminous, but they are faint compared to other stars.
7.
What is the fourth stage in the life cycle of an average star?
Correct Answer
B. Planetary Nebula.
Explanation
The fourth stage in the life cycle of an average star is the planetary nebula. During this stage, the star has exhausted its nuclear fuel and begins to shed its outer layers, forming a glowing shell of gas and dust called a planetary nebula. This process occurs when the star's core collapses and heats up, causing the outer layers to expand and create a beautiful nebula. Eventually, the remaining core will cool down and become a white dwarf, marking the final stage in the star's life cycle.
8.
When is an average star created?
Correct Answer
C. In the second stage.
Explanation
In the second stage, an average star is created. This suggests that the process of star formation occurs in multiple stages, with the second stage being the point at which an average star is formed. The other options provided (the first stage, during the Red Shift, and when a black hole forms) are not mentioned as the specific stage at which an average star is created, indicating that they are not the correct answer.
9.
What is a Nova?
Correct Answer
A. A nuclear explosion caused by a growth of hydrogen onto the surface of a white dwarf star.
Explanation
A nova is a nuclear explosion that occurs on the surface of a white dwarf star due to the accumulation of hydrogen. As the hydrogen builds up on the surface of the star, it undergoes a thermonuclear reaction, causing a sudden increase in brightness and the release of a large amount of energy. This explosion is known as a nova.
10.
What is a Quasar?
Correct Answer
C. A star-like object that may send out radio waves and other forms of energy.
Explanation
A quasar is a star-like object that may send out radio waves and other forms of energy. Quasars are extremely luminous and distant objects found in the center of galaxies. They are powered by supermassive black holes and emit enormous amounts of energy across the electromagnetic spectrum, including radio waves. The term "star-like" refers to their appearance in the night sky, as they resemble stars, but they are not actual stars.