The Taurus molecular cloud (TMC-1) is an interstellar molecular cloud in the constellations Taurus and Auriga. This cloud hosts a stellar nursery containing hundreds of newly formed stars. The Taurus molecular cloud is only 140 pc away from Earth, making it possibly the nearest large star formation region. It has been important in star formation studies at all wavelengths.
Taurus molecular cloud (Herschel Space Observatory)
A molecular cloud, sometimes called a stellar nursery (if star formation is occurring within), is a type of interstellar cloud, the density and size of which permit absorption nebulae, the formation of molecules (most commonly molecular hydrogen, H2), and the formation of H II regions. This is in contrast to other areas of the interstellar medium that contain predominantly ionized gas.
Astronomer Henk van de Hulst first theorized hydrogen could be traceable in interstellar space using radio signals.
Plaque commemorating the discovery of 21-cm radiation from the Milky Way
Left to right: Jan Oort, Hendrik C. van de Hulst, Pieter Oosterhoff. Jan Oort had a pivotal role in the research that lead to the discovery of molecular clouds.
Penzias and Wilson with the Holmdel horn antenna used to detect microwave emissions from the Big Bang
