I had a conversation with Ana Bonaca (Harvard) early today about the sky emission lines in sky fibers in Hectochelle. We are trying to understand if the sky is at a consistent velocity across the device. This is part of calibrating or really self-calibrating the spectrograph. It's confusing though, because the sky illuminates a fiber differently than the way that a star illuminates a fiber. So this test only tests some part of the system.
At the Brown-bag talk, Bob Johnson (Virginia) spoke about exo-moons and in particular exo-Ios. Yes, analogs of Jupiter's moon Io. The reason this is interesting is that Io interacts magnetically and volcanically with Jupiter, producing an extended distribution of volcanically produced ions in Jupiter's magnetic field. It is possible that transmission spectroscopy of hot Jupiters is being polluted by volcanic emissions of very hot moons! That would be so cool! Or hot?