6.7 Astronomy Research Paper

9.7 Option – Astrophysics
1. Our understanding of celestial objects depends upon observations made from Earth or from space near the Earth 1) Discuss Galileo’s use of the telescope to identify features of the Moon.
The Tuscan physicist, mathematician and philosopher Galileo Galilei constructed one of the earliest telescopes which he pointed towards the heavens. Galileo observed the moons of Jupiter, the phases of Venus and the rough features of the moon. This new evidence conflicted with the Ptolemaic model and the idea of perfect ‘heavenly’ bodies. 2) Discuss why some wavebands can be more easily detected from space
Selective absorption by the Earth’s atmosphere of some wavelength bands affects how and where we study EM radiation
Elements above iron are formed by neutron capture in the extreme conditions of a supernova. 5) Explain how the age of a globular cluster can be determined from its zero-age main sequence plot for an H-R diagram
Globular clusters form a close by group of stars that are usually born at the same time. The largest/brightest stars move off the main sequence first. When you see a cluster with no large luminous main sequence stars you can conclude that the cluster is very old. The point on the main sequence where the star plot turns off onto the red giant branch is known as the turn-off point. The earlier the turn-off point, the older the star cluster is. 6) Explain the concept of star death in relation to:
Planetary nebula: Glowing gas that surrounds a central star, they’re formed when a star 8 solar masses or less has finished fusing helium surrounding a core of carbon and oxygen. The star becomes unstable but its small size cannot fuse heavier elements. It pulsates and throws outer material into space. The gas glows as it is being radiated by the remaining part of a star which eventually turns into a white
It’s composed of mostly oxygen and carbon. Its surface is white due to the small surface area compared to the amount of heat being radiated. It’s formed from a planetary nebula.
Neutron stars/Pulsars: Formed from a supernova, it has a mass of 1.4 - 3 solar masses. Gravity forces electrons and protons to merge and form a continuous type of extremely dense star; a neutron star, made entirely of Neutrons. It may have a diameter of 10 – 20km. Because it’s smaller it spins very fast, it can have a period of a few milliseconds. It is detected with radio waves by the fast pulsations it gives off every time it spins.
Black holes: If the remnant of a supernova core is more than five solar masses it will collapse into a neutron star and then a black hole. Black holes are referred to as a singularity as they have unlimited density and no real dimensions. The gravity is so strong that not even light can escape; the point at which that happens is called the ‘event horizon’. They are detected by witnessing their effects on planets