The JHI are pleased to announce a scientific conference to honour the life's work of our own Don Kurtz! The conference, Understanding the roles of rotation, pulsation and chemical peculiarities in the upper main sequence, will be held in the English Lake District from 11-16th September 2016. For more information, please visit the conference website
The stellar astrophysics group studies the formation of stars and their planetary systems, the properties of stars, and how stars effect their environments. We pursue observational programmes in the X-ray, ultraviolet, optical, infrared, mm and radio bands using ground-based (e.g. JCMT, eMerlin) and space-borne observatories (Kepler, Herschel, XMM-Newton). By combining photometric, spectroscopic and imaging observations we unravel the interactions between the stars and their environments, and the processes within the stars themselves. We additionally pursue theoretical and computational studies of how Sun-like stars form in collapsing clouds, and how low-mass stars, brown dwarfs and planets form in protostellar discs.
Asteroseismology is the study of oscillations and pulsations in a star using a collection of observational techniques. These pulsations provide a unique view into the interiors of stars. Professor Donald Kurtz applies the techniques of Asteroseismology to see beneath the surfaces of the stars, a place Sir Arthur Eddington thought was “less accessible to scientific investigation than any other region of the Universe”. Professor Kurtz is co-author of the fundamental textbook, Asteroseismology (Springer Publishers, 2010, 866 pages).
Circumstellar Matter and Interacting Binaries
Many stars eject copius quantities of gas and dust, particularly in the late and early stages of their lives. By studying this material we trace the events in the stars leading to the ejection. We also examine a number of fundamental processes, including nebula shaping, shock interactions, and dust formation and chemistry. Binary stars make up perhaps 40% of the "bright lights" in our night sky. In many cases the stars of a binary system interact and exchange matter via gravitational transfer and an accretion disc. This disc can out-shine the stars as frictional and tidal effects convert orbital angular momentum to light. By observing the effects of eclipses on the light curve and correlating this with the x-ray spectra we can learn a considerable amount about the structure of and activity on the disc.
Star Formation and Exoplanets
Stars form within the cores of cold, dense clouds of interstellar gas and dust. When gravity dominates over turbulent, thermal, and magnetic support, the cores of these clouds collapse to form stars. The stellar masses range from a few times the mass of Jupiter, the largest planet in our Solar System, up to a few hundred times the mass of our Sun. We investigate the initial conditions of star formation using observations from ground-based (e.g. JCMT, PdBI) and space-borne observatories (e.g.Herschel), and radiative transfer modelling. We also explore the physics of protoplanetary discs that relate to the formation of giant exoplanets, brown dwarfs and low-mass stars, and develop novel computational hydrodynamics and radiative transfer methods.
The Sun is the closest star to Earth and therefore we understand it in more detail than any other star. To compare the activity of the Sun with the activity of other stars that are much farther away we must look to large-scale solar phenomena. The study of the solar-stellar connection has been pursued using observations of flares on rapidly rotating Sun-like stars.
Header Image : Simulated Nanoparticle (Marco Pinna, Joe Smerdon), Solar disk with SDO (NASA UClan SDO archive), V838 Monocerotis (NASA/STScl), NGC7424 (Gemini Observatory), M74 (NASA Hubble Space Telescope) NASA,and ESA ; and solar plume courtesy of SOHO /EIT consortium
Author: SPS Eyres, Last Updated: 11 November 2005, 10:35