Talk Details

Monday, May 5, 2014 - 11:00am

David Martinez-Delgado (ZAH/ARI):

"The search for faint dwarf galaxies in the Local Volume with tiny telescopes"

Abstract. The L-CDM paradigm predicts a large number of dwarf galaxies in the Local Volume, only a small fraction of which have so-far been discovered. It is thus of broad interest for galaxy formation theory to carry out a full inventory of the numbers and properties of dwarfs, both satellites and isolated. Small aperture (10-15 cm) telescopes, combined with the new generation of commercial CCD cameras, can be valuable instruments for finding faint dwarf companions around the Local Group spirals. The short focal ratio of these telescopes allows these stellar systems to be traced as unresolved, diffuse light structures -- a similar approach was successfully used to discover stellar tidal streams around nearby spirals. In this talk, I discuss this new project to search for faint nearby satellites with amateur telescopes. I also present our first discovery: DGSAT I, a probable isolated dwarf spheroidal galaxy projected on a halo field of M31, that was previously missed by surveys based on resolved star counts and on the H-I radio line.