The bright blob of hydrogen gas cataloged as N88A is seen at the right. It measures a mere 3 light years across. Emerging from the cool, dusty interstellar medium in a nearby irregular galaxy known as the Small Magellanic Cloud , N88A hides hot young stars at its core. The false-color Hubble Space Telescope image was recorded in the characteristic “H-alpha” light emitted by hydrogen atoms as they are ionized by the young star's energetic ultraviolet light and then recombine. Other regions of ionized hydrogen ( H II regions ) which surround new born stars can be over a thousand light-years across but astronomers now recognize that these small ionized hydrogen blobs contain some of the most massive stars known.
Media Credits & Attribution
Credit: M. Heydari-Malayeri (Paris Observatory) et al., WFPC2, HST, ESA, NASA