Wayne State University

Aim Higher

Study of Supernovae

Professor David Cinabro

Supernovae are stars that explode when they reach the end of their life. For about one week a single star glows as bright as an entire galaxy of billions of stars, before it fades into eternal darkness. What is most amazing is that one class of supernova, type Ia's, produce a well known amount of light. Thus they can be used as a distance measure. By measuring the distance to supernova as a function of time we are able to measure the expansion history of the universe. This reveals that some mysterious force, called Dark Energy, is pushing the universe apart towards a cold, dark, lifeless future.

The Sloan Digital Sky Survey Supernova Search uses the 2.5 meter telescope at the Apache Point Observatory in New Mexico to search for and study supernova and study cosmology. Professor Cinabro is a member of this project and has special interest in measuring the rate of type Ia supernova which reveals the history of the rate of star formation in the universe, the effects of the galaxy host on the type 1a supernova trying to answer the question if brighter supernova occur in young star forming galaxies, and studying other sorts of supernova that arise when stars run out of fuel, collapse, and explosively rebound.

Professor Cinabro is also a member of the Large Synoptic Survey Telescope project. This is a plan to build an 8.5 meter telescope in Chile which will comprehensively survey half of the sky every other night. It will provide an incomparable sample of transient celestial phenomena, including a definitive sample of supernova.

For more information on this reserch, visit :
The Sloan Digital Sky Survey Supernova Search: http://sdssdp62.fnal.gov/sdsssn/sdsssn.html
The Large Synoptic Survey Telescope: http://www.lsst.org/lsst_home.shtml


Study of Neutron Stars

Professor Edward Cackett

Neutron stars are fascinating objects. They are formed in a supernova explosion at the end of a star's life: what is left after the explosion is a tiny, incredibly dense star. They have a mass a little more than that of our Sun, yet are crammed into sphere only about 20-30 km across.  This makes the very centres of neutron stars more dense than atomic nuclei! On Earth, we cannot reproduce those conditions experimentally, which makes neutron stars a unique astrophysical laboratory to study the most dense observable material in the Universe.  What neutron stars are made of is a vital question that underpins our knowledge of the way fundamental physics works - how does matter behave when it is compressed to such extreme densities?

Dr. Cackett uses world-leading X-ray satellites to observe neutron stars in binary systems where a star similar to the Sun and a neutron star orbit each other.  In such systems the gravity of the neutron star can pull matter from the companion, which then spirals down onto the neutron star forming a hot disk of gas (an 'accretion disk') around it.  Dr. Cackett studies this accretion process and its effects on the neutron star in order to learn about the nature of these superdense objects.

For more information about this research, visit
The Chandra X-Ray Observatory website:  http://chandra.harvard.edu/xray_sources/neutron_stars.html