Lester, John

Ph.D. | Professor | AstronomyEarth and Space Science

Contact Information

Phone: 
905 828 3818
Fax: 
905 828 5425
Room: 
DV4035
Mailing Address: 
3359 Mississauga Road
City: 
Mississauga
Province: 
Ontario
Postal Code: 
L5L 1C6
Picture of John Lester

Research

I study the physical processes that occur in the atmospheres of individual stars. Stellar atmospheres are often used as tools for the study of "macro" topics, such as the evolution of the Milky Way or the distance to other galaxies, and these applications interest me too. However, I am more intrigued by the astrophysics that takes place in the stellar atmosphere, which is an extremely complex boundary layer between the dense stellar interior and near vacuum of space. There are fundamental physical processes occurring in this environment that are still poorly understood because the size, temperatures, pressures, velocities and magnetic fields cannot be recreated in terrestrial laboratories. My approach to these problems is a combination of observation and computer modeling.

Publications

Neilson, H. R. and Lester, J. B., "Spherically symmetric model stellar atmospheres and limb darkening. II.  Limb-darkening laws, gravity-darkening coefficients and angular  diameter corrections for FGK dwarf stars",  /Astronomy & Astrophysics/, vol. *556*, Article A86, 8 pages, August  2013.

Neilson, H. R. and Lester, J. B., "Spherically-symmetric model stellar atmospheres and limb darkening. I.  Limb-darkening laws, gravity-darkening coefficients and angular  diameter corrections for red giant stars", /Astronomy & Astrophysics/, vol. *554, Article A98, 10 pages, June 2013.

Lester, J. B, Dinshaw, R. and Neilson, H. R., "Indicators of Mass in Spherical Stellar Atmospheres", /Publications of the Astronomical Society of the Pacific/, vol. *125*, 24 pages, 2013.

Neilson, H. R. Lester, J. B., "Using limb darkening to measure fundamental parameters of stars", /Astronomy \& Astrophysics/, vol. *544*, Article 117, 7 pages, 2012.

Neilson, H. R. Lester, J. B., "Limb darkening in spherical stellar atmospheres", /Astronomy & Astrophysics/, vol. *530*, Article 65, 8 pages, 2011.

Lester, J. B., Review of "The Colors, Bolometric Corrections and Effective Temperatures of the Bright Stars'' by Johnson (1964)", /RevMexAA (Serie de Conferencias)/, vol. *39*, pp. 77-82, 2011.

Neilson, H. R., Ngeow, Chow-Choong, Kanbur, Shashi M. and Lester, J. B., "Testing Mass Loss in Large Magellanic Cloud Cepheids Using Infrared and  Optical Observations. II. Predictions and Tests of the OGLE-III  Fundamental-Mode Cepheids", /The Astrophysical Journal/, vol. *716*, pp. 1136-1150, 2010.

Neilson, H. R., Ngeow, Chow-Choong, Kanbur, Shashi M. and Lester, J. B., "Testing Mass Loss in Large Magellanic Cloud Cepheids  Using Infrared and Optical Observations", /The Astrophysical Journal/, vol. *692*, pp. 81-90, 2008.

Neilson, H. R. and Lester, J. B., "On the Enhancement of Mass Loss in Cepheids due to  Radial Pulsation.  II. The Effect of Metallicity", /The Astrophysical Journal/, vol. *690*, pp. 1829-1838, 2008.

Lester, J. B. and Neilson, H. R., "SAtlas: Spherical Versions of the Atlas Stellar Atmosphere Program", /Astronomy \& Astrophysics/, vol *491*, pp. 633-641, 2008. 

Neilson, H. R. and Lester, J. B.,"Determining Parameters of Cool Giant Stars by Modeling  Spectrophotometric  and Interferometric Observations Using the SAtlas  Program", /Astronomy & Astrophysics/, vol. *490*, pp. 807-810, 2008.

Neilson, H. R. and Lester, J. B., "On the Enhancement of Mass Loss in Cepheids due to Radial Pulsation", /Astrophysical Journal/, vol. *684*, pp. 569-587, 2008.

 

Other

Education: 
B.A. - Northwestern University (1967)
M.S. - University of Chicago (1969)
Ph.D. - University of Chicago (1972)
Postdoctoral Research - Harvard-Smithsonian Center for Astrophysics (1972-76)