Stars form and undergo a complex life cycle over billions of years.
What is the name given to the massive interstellar cloud of gas and dust that serves as the birthplace of stars?
Which fundamental force is responsible for the inward collapse of a molecular cloud that leads to the formation of a protostar?
Complete the sentence: During the main sequence phase of a star like our Sun, hydrogen nuclei undergo nuclear fusion / fission / decay to form helium nuclei, releasing energy.
X-rays and infrared radiation are emitted from the surface of an active star and travel across the vacuum of space to an orbiting telescope. Which statement correctly describes the time taken for these two types of radiation to travel this distance?
X-rays have a much shorter wavelength than infrared radiation. Complete the sentence: Compared with the frequency of infrared radiation, the frequency of X-rays is smaller / the same / greater.
A hot young protostar and a cooler star of the same surface area both emit thermal radiation. Compare the rate of infrared radiation emitted by the hotter protostar with that of the cooler star, and give a reason for your answer.