Lesson 5 & 6: Nova and Supernova |
In Lesson 5 & 6, we will explore Novae and Supernovae. The word nova in latin literally means “new star”. Ancient civilisation called it nova which means the creation of new star. While it appear to the naked eye that a new star has been created, in the contrary, nova is caused by star near the end of its life! Image Credit: ESA/Hubble & NASA Acknowledgement: Gilles Chapdelaine / CC BY 3.0 |
When two stars are sufficiently close to one another, gravitational forces pull materials from one star to the other. Gas (mostly hydrogen) are transferred from the larger companion star to the dense hot white dwarf. The increase in hydrogen on the surface of the white dwarf ignites and start a nuclear fusion in a runaway manner and triggers a large explosion. Image Credit: NASA/CXC/M.Weiss |
Supernova is the largest explosion in space (more massive than a nova). It is equivalent to 1028 megaton bomb or a few octillion nuclear bomb! (1 octillion is 1 followed by 27 zeros!) The explosion is so bright that it can briefly outshine the entire galaxy, from which it occurs. Image Credit: NASA, ESA, J. Hester and A. Loll (Arizona State University) |
Supernovae play a key role in enriching the interstellar space with higher mass elements. Elements from carbon, oxygen, nitrogen to heavy elements such as silicon, calcium and iron are blasted to space. These higher mass elements were later use to form new stars, solar systems and planets. Image Credit: Judy Schmidt / CC BY 2.0 |
Page background: Image Credit: NASA, ESA, HEIC, and The Hubble Heritage Team (STScI/AURA)