1. Light Curves of the Dwarf Nova U Gem: A Diagnostic of Accretion Disk Evolution Larry Molnar Calvin College Grand Rapids, Michigan

2. Outline Calvin-Rehoboth Twin Telescopes Project Dwarf Novae U Gem Preliminary Light Curves

3. Calvin-Rehoboth Twin Telescope Project NSF-CCLI funding Two 16” OGS telescopes –One in Grand Rapids, MI Hands-on experience for students Development platform for remote site –One in Rehoboth, NM (35.5N,108.6W) Unattended robotic operation High throughput

9. Dwarf Novae White dwarf + red dwarf Red dwarf fills Roche Lobe Angular momentum loss leads to mass transfer via an accretion stream, and formation of an accretion disk Disk conditions do not permit steady-state

10. U Gem Brightness: 10-14 magnitude Mass ratio: 0.25 Orbital period: 4.24 hours Outburst time scale: 3-4 months Inclination: hot spot is eclipsed by red dwarf

38. Conclusions U Gem data demonstrate capabilities of new system Comparison of eclipses before and after outburst are consistent with accretion disk radius increasing gradually through the quiescent phase