hip-81497

Its story

42 Herculis is an M-type red giant 414 light-years away, one of dozens of cool, swollen stars dotting the classical figure of Hercules. Its atmosphere barely reaches 3,500 degrees, hence that deep red that sets it apart from the youthful blues of neighbouring constellations. It shines this way because it has already crossed the final threshold of its evolution and ballooned its envelope to hundreds of solar diameters.