Jacob Robert Emden (4 March 1862 – 8 October 1940) was a Swiss astrophysicist and meteorologist. He is best known for his book, Gaskugeln: Anwendungen der mechanischen Wärmetheorie auf kosmologische und meteorologische probleme (Gas spheres: Applications of the mechanical heat theory to cosmological and meteorological problems), published in 1907. It presents a mathematical model of the behaviour of polytropic gaseous stellar objects under the influence of their own gravity, known as the Lane-Emden equation.