A velocity field is given by V = xi + x(x 1)(y + 1)j ,where u and are in ft/s and x and y are in feet. Plot the streamlinethat passes through x = 0 and y = 0. Compare this streamlinewith the streakline through the origin.
Steller and Galactic Astronomy Notes: 2/16/2016 Chapter 16: Star Birth Stellar Nurseries o Where do Stars form Stars form in dark clouds of dusty gas in interstellar space. The gas between the stars is called the interstellar medium. It is high in density (300 molecules per cubic centimeter) and cold(10-30K). The clouds are made of 70% H for2, 28% He and 2% other stuff. Most of the matter is in the form of molecules. Tiny solid particles of interstellar dust block our view to stars behind it. Long wavelength infrared light passes the clouds easily. Observing the infrared light from a cloud can reveal the newborn star embedded inside it. This will let us see new stars as they are being born. Brighter regions have more stars forming o Why do Stars form Gravity must overcome thermal energy to cause the stars to collapse into a star. A molecular cloud must contain at least a few 100 solar masses for gravity to overcome pressure Emissions from molecules in a cloud prevent a pressure buildup A cloud must have even more mass to begin collapsing