What causes a gravitational field around an object?

Si una estrella no tiene paralaje medible, ¿qué puedes inferir?

A50.0g sample of liquid water at 0.0 c ends up as ice at -20.0 c. how much energy is involved in this change?

An object becomes electrically charged when: electrons are created in it electrons from it are destroyed electrons are transferred to it protons from it are destroyed protons are created in it