Importance

Mapping the universe

Type la supernovae are landmarks in the universe and are essential to mapping it’s layout. Charting our universe is important as it has revealed information regarding the universe's expansion rate and the evolution of galaxies.

Type Ia supernovae are known as "standard candles" because they are measurable and have a known luminosity. They all peak at intrinsic (similar) brightness and, therefore, serve as landmarks for astronomers mapping space. By observing their brightness, scientists can infer their distance from Earth; the dimmer the light, the further the supernova.

They make these maps by monitoring redshift, a key concept in understanding the universe's expansion. Redshift occurs when light wavelengths are stretched (the Doppler effect) due to increasing distance between the Earth and the supernova and this causes the wavelengths to move towards the red end of the spectrum. By studying this redshift, scientists can determine how far a supernova is from us and gain insights into the universe's expansion rate. Using data from numerous supernovae, scientists formulate an average, constructing three-dimensional maps of the universe that depict galaxy distribution, cosmic structure, and the expansion rate. In summary, mapping the universe is crucial to unravelling its history and making predictions about its formation.

Figure 2. Diagram demonstrating red shift caused by Doppler effect

Discoveries

Supernovae have been fundamental to discovering various parts of the solar system, such as the formation of elements, cosmic structure formations, and dark energy. Supernova remnants, also known as SNRs, fuse with space debris to make up almost all the matter heavier than iron in our solar system. Studying SNRs helps scientists explain element synthesis and nuclear physics. Supernovae are sites of intense atomic reactions, where elements heavier than iron are synthesized through nucleosynthesis and r-process. Observations of the elements that supernovae comprise provide valuable insights into the origin of elements in the universe

Moreover, given that almost all celestial bodies are made up of elements heavier than iron, understanding and tracking the life of supernovae give insight into cosmic structure formations and the life cycles of stars. Astronomers can use the data collected from these observations to prove theories based on space’s evolution.

Furthermore, the distance measurement of a supernova relative to the Earth plays a crucial role in the theory of dark energy. The hypothetical dark energy would counteract the gravitational pull of galaxies, leading to an accelerated expansion instead of deceleration. Two independent teams of astronomers studied supernovae and discovered that the universe's expansion rate is accelerating rather than slowing down. The primary evidence was based on the observation that Type Ia supernovae are farther away than expected due to accelerated expansion. While this evidence supports the existence of dark energy, the theory remains unproven.

Figure 3. Shows the redshift due to the distance of Earth to a supernova; comparing the expected ratio due to the laws of physics (blue line) to the actual data (green line), the difference is the proof for dark energy theory.

Figure 2. Diagram demonstrating red shift caused by Doppler effect

Figure 3. Shows the redshift due to the distance of Earth to a supernova; comparing the expected ratio due to the laws of physics (blue line) to the actual data (green line), the difference is the proof for dark energy theory.

Have any Questions?

Ask us in class or on the Q&A page!

Figure 2. Diagram demonstrating red shift caused by Doppler effect

​

Figure 3. Shows the redshift due to the distance of Earth to a supernova; comparing the expected ratio due to the laws of physics (blue line) to the actual data (green line), the difference is the proof for dark energy theory.