2016-07-07

binary stars, Nyquist, and TESS

At MPIA Galaxy Coffee, I learned about star-formation rates and dust in galaxy disks from Sarah Leslie (MPIA) and about galaxy nuclear star cluster formation from Nicolas Guillard (MPIA). Afterwards, I had a long conversation with Simon J. Murphy (Sydney) about his work on asteroseismic binary stars. I asked him to try doing some experiments towards building a (less approximate) likelihood for asteroseismic binary signals. We also talked about super-Nyquist frequency determination, and also his (very clever) idea for improving TESS by having the satellite disrupt its periodic sampling of stars each time it points back at Earth to downlink. This breaks the pure periodicity of the time sampling (in the spacecraft frame) and therefore delivers more information, without overly complexifying spacecraft operations or data analyses.

Late in the day I thought about weighing stars in Gaia using the “lensing” of unbound star trajectories. I am not sure it is possible, but it is interesting to think about.

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