Sh2-64, also known as Westerhout 40 (W40), is a prominent HII region and active star-forming complex.  Sh2-64 is an important site for the study of early stage stellar evolution and formation.  It is located within the Serpens-Aquila Rift about 1,400 light years distant^[1].  Steward Sharpless included this remarkable object in his catalog of HII regions as the 64th entry^[3].

The image above was acquired using an optical wavelength filter set (LRGB).  A wide-field astrograph (RH200) was used to display the central HII region, as well as the surrounding star fields and dust clouds which are prominent in this area of the Milky Way.

A dense molecular cloud of dust and gas overlaying the core of Sh2-64 (W40) optically obscures it from view^[1,2].  Observations utilizing instruments such as the infrared Spitzer Space Telescope^[4] are able to penetrate the obscuring clouds and reveal nebular details, embedded evolving protostars, and young massive O and B type stars located within this remarkable object^[2].