Patrick Durrell and John Feldmeier study both nearby and distant galaxies using ground-based and space-based telescopes. They are both particularly interested in intracluster stars, stars that lie between the galaxies in a galaxy cluster. Some samples of their research are given below:
VICS: The VIrgo IntraCluster Star project
Using the Hubble Space Telescope, Dr. Durrell and Dr. Feldmeier are part of a 13-member international team of scientists that have taken a 37-orbit exposure near the center of the Virgo Cluster of galaxies. The goal here was to measure the properties of intracluster red giant stars through the imaging. By a lucky coincidence, a small dwarf galaxy was discovered in the field (seen on the left), offering the first chance to study the stellar population of a dwarf galaxy in a galaxy cluster
Using Planetary Nebulae to Study Galaxies and Galaxy Clusters
Planetary Nebulae are an ending phase of a star's life, where they become very bright in just a narrow emission lines of specific colors. This makes them relatively easy to detect and study. Once they are found, extragalactic planetary nebulae can help find the distances to nearby galaxies, and to measure the velocities of stars around galaxies. On the left is an image of the famous galaxy pair M51. The colored points refer to planetary nebulae whose radial velocities have been measured. A tidal "tail" of planetaries can be seen as the red and oranges structure on the upper left side of this image.
Galactic and Stellar Astronomy
Studying Open and Globular Clusters of our Galaxy
Dr. Durrell studies open and globular star clusters in our Milky Way Galaxy. By measuring the brightnesses and colors of these stars, astronomers can determine the age and chemical content of these stars, and gain clues as to how our Galaxy was formed. On the left is an image of the globular cluster NGC 6093.
Studies of Stellar Variability
Dr. Feldmeier studies stars that vary in brightness. By studying which stars vary and which stay constant in brightness, astronomers can learn about the interiors of stars and search for extra-solar planets. On the left is a light curve of the RR Lyrae variable star CL Boo.