Researchers have pieced together Hubble images of jets from newborn stars into timelapse movies that reveal the interstellar fluid mechanics responsible for the formation of stars like our sun. These jets stream out clumps of matter that has fallen on the new star. When faster moving eddies impact slower ones, bow shocks can form, much like shockwaves running before an airplane. See more HD video of these jets and bow shocks here. #
In early June, NASA’s Solar Dynamics Observatory recorded a stunning coronal mass ejection, in which larger than usual quantities of cool (relatively speaking) plasma erupted from the surface of the sun and rained back down along magnetic field lines. Plasma is an ionized gas-like state of matter subject to the same laws that govern more familiar fluids like water or air, with the additional caveat that, being electrically conductive, plasmas also obey Maxwell’s equations. #
NASA’s Solar Dynamics Observatory has found evidence of Kelvin-Helmholtz waves in the sun’s corona. These waves, which occur between two fluids of different densities or moving at different speeds, are similar to the iconic waves surfers ride. Researchers suspect that this turbulent motion may help explain why the corona is 1,000 times hotter than the surface of the sun. #
This high-resolution photo of our sun shows the structure of calcium plasma on the surface of the sun. Plasmas are governed by the same physics as our familiar earthbound fluids but are also extremely sensitive to magnetic fields. Their branch of fluid dynamics is often referred to as magnetohydrodynamics (MHD), where the Navier-Stokes equations have to be solved in conjunction with Maxwell’s equations. (via Bad Astronomy)
When a fluid in a gravitational field is heated from below, it can develop a Rayleigh-Benard instability which causes the formation of convection cells as in the video above. The hexagonal shape of the cells is due to the boundary conditions of the fluid. It’s possible to form other shapes like spirals. The same mechanism drives the formation of granules on the photospheres of stars like our sun.
Celebrating the physics of all that flows. 