A search for nearby red dwarfs

Dr. Lepine's research focuses of the search for stars located within only a few hundred parsecs of the Sun. This is small by astronomical standards, with our own Galaxy's spiral disc extending over more than 25,000 parsecs in diameter. In this immensity, the nearby stars are important because they can be studied from much closer, providing much more details than very distant objects. A complete census of the nearby stars is also like a blood test of the Galaxy, telling us which types of stars exist in the Universe and what their relative numbers are. It turns out that stars like our Sun (also known as "G" stars) are relatively uncommon, while stars smaller and cooler than the Sun (also known as "red dwarfs" or "M" stars, like the star Proxima Centauri) are very abundant.

Collaborators: Kelle Cruz (Hunter College), Ian Neill Reid (Space Telescope Science Institute), Michael M. Shara (AMNH), John Thorstensen (Dartmouth College).

A search for nearby white dwarfs dwarfs

White dwarfs are the fading remnants of dead stars. They have stopped burning hydrogen, and shine only from their residual heat. About the size of planet Earth, they pack as much mass as the Sun. They have a very hot, bright surface, but are not very luminous because they are much smaller than regular stars; as a result, they are quite faint on the sky, and are fairly difficult to find. I have been searching for white dwarfs in the SUPERBLINK catalog of stars with large proper motions, looking for stars that are both blue and faint (which means they are hot, but are not very luminous). We are now planning to observe these stars with a spectrograph, to look for the telltale spectral signatures of white dwarfs.

Collaborators: Pierre Bergeron, Marie-Michele Limoges, Alessandros Gianninas (all from Universite de Montreal)

A search for binary stars in the Galactic halo

In construction

Targets for planets: the best place to search for exoplanets

In construction