Answer to Question 1
Neutrinos travel directly out of the Sun to the Earth in about 8 minutes. Neutrino detectors can detect these, confirming the nuclear reactions happening in the Sun's core.
Answer to Question 2
An interstellar cloud, disturbed in some way, begins to gravitationally collapse. It heats up as it collapses, and spins faster. (If the spinning is too great it may defeat the entire process, as the protostar tears itself apart.) Eventually the core of the cloud is hot enough that it develops a definite glowing edge (photosphere), and begins to resemble a star. When the core temperature reaches 10 million K and nuclear fusion of hydrogen into helium begins, it is officially a star. When the outward pressure equalizes with gravity, the star enters the main sequence. Collisions between galaxies can set up a shock wave to initiate collapse, as can the shock waves from supernovae and the density wave moving through the spiral arms of the galaxy.
Bones of the Face and Skull (Lateral View)
Placing an endotracheal tube in the trachea with direct visualization by laryngoscopy.
Medial view of sagittal section
Posteroinferior view of skull
Right lateral view of several articulated thoracic vertebrae