Lester, John
Contact Information
3359 Mississauga Road North
Mississauga, Ontario
L5L 1C6
Research
I am interested in the physical processes that occur in the atmospheres of individual stars. While stellar atmospheres are often used as tools for the study of "macro" topics, such as the evolution of the Galaxy or the extragalactic distance scale, and these applications interest me too, I am more intrigued by the "micro" astrophysics that takes place in the stellar atmosphere, which is an extremely complex boundary layer between the stellar interior and space. There are fundamental physical processes occurring in this environment that are still poorly understood because the scale, temperatures, pressures, velocities and magnetic fields cannot be recreated in terrestrial laboratories. My approach to these problems is primarily observational, although I also employ modeling.
Publications
Tycner, C., Lester, J. B., Hajian, A. R., Armstrong, J. T., Benson, J. A., Gilbreath, G. C., Hutter, D. J., Pauls, T. A. and White, N. M., "Properties of the H-alpha-Emitting Circumstellar Regions of Be Stars", Astrophysical Journal, vol. 624, pp. 359-371, 2005.
Tycner, C., Hajian, A. R., Armstrong, J. T., Benson, J. A., Gilbreath, G. C., Hutter, D. J., Lester, J. B., Mozurkewich, D. and Pauls, T. A., "The Circumstellar Envelope of zeta Tauri through Optical Interferometry", Astronomical Journal, vol. 27, pp. 1194-1203, 2004.
Caron, G., Moffat, A. F. J., St-Louis, N., Wade, G. A. and Lester, J. B., "The Lack of Blue Supergiants in NGC 7419, A Red Supergiant-Rich Open Cluster with Rapidly Rotating Stars", Astronomical Journal, vol. 126, pp. 1415-1422, 2003.
Tycner, C., Hajian, A. R., Mozurkewich, D., Armstrong, J. T., Benson, J. A., Gilbreath, G. C., Hutter, D. J., Pauls, T. A. and Lester, J. B., "A Method for Internal Calibration of Optical Interferometer Data and Application to the Circumstellar Envelope of gamma Cassiopaei", Astronomical Journal, vol. 125, pp. 3378-3388, 2003.
Tycner, C. and Lester, J. B., "Simulating Spectrophotometric Fluctuations of p-Mode Oscillations in Solar-like Stars", Publications of the Astronomical Society of the Pacific, vol. 114, pp. 330-339, 2002.
Hamilton, D. and Lester, J. B., "A Technique for the Study of Stellar Convection: The Visible Solar Flux Spectrum", Publications of the Astronomical Society of the Pacific, vol. 111, pp. 1132-1143, 1999.
Short, C. I. and Lester, J. B. "Modeling the Violet Spectral Region of Cool Stars: Line and Continuous Opacity", Astrophysical Journal, vol. 469, pp. 898-905, 1996.
Sigut, T. A. A. and Lester, J. B., "Infrared Rydberg Emission Lines in Early-Type Stars: I. Mg II", Astrophysical Journal, vol. 461, pp. 972-992, 1996