Home » For educators » Science Cases » The Stars » Supernovae Detection in Nearby Galaxies - https://cesar-tools.cosmos.esa.int/web/index.php?Section=Supernovae_Detection (Printable version, go to full version) Supernovae Detection in Nearby Galaxies
The telescope is going to systematically monitor several hundreds of spiral galaxies that lie less than 300 million light years from our Milky Way, in hopes of capturing the rise in light from a supernova outburst. Supernovae of type-Ia are very important astrophysical objects because of their use as absolute distance indicators. Supernovae Type IaType Ia supernovae are thought to be interacting binary star systems in which a white dwarf star is obtaining mass via an accretion disk from the star companion. As the white dwarf accretes more and more matter and goes over the Chandrasaekar limit (1.4 solar masses), a thermonuclear explosion results. Since this critical limit of 1.4 solar masses consistently sets the amount of material in the blast, these types of supernovae are more useful as standard candles than other types. Early detection of supernovae explosions is important to get vital spectroscopic information for type classification while the system is still bright and spectroscopy still possible.
Is also important the observation of the outburst maximum light, which gives information about its distance. Assuming the luminosity can be established for the type Ia supernovae, its absolute magnitude is then known. Observation of its apparent magnitude yields the distance to it and the galaxy in which it resides by the so-called distance modulus, m - M = 5 log d - 5, where m and M are the apparent and absolute magnitudes, and d is the distance in parsecs to the supernova and host galaxy. Supernovae Monitoring Program
Earliest possible observations are desired as the supernova fades from maximum light during the weeks after the outburst. Early detection of supernovae candidates requires systematical vigilance. The appearance of a supernova in any one galaxy is an extremely rare occurrence, but by monitoring many galaxies, the likelihood of discovery increases.
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