Harvard-Smithsonian Astrophysician Center reasons reasons for the origin of a huge bubble surrounding the solar system, a thousand light-year-old diameter. This structure, known as the local bubble, originated over the last 14 million years, and at its borders are areas of star formation. The results of the study are published in the Nature magazine.
Astrophysics analyzed the data of the Cosmic Observatory of the GAIA European Space Agency (ESA). It turned out that about 15 supernovae had to explode to form a modern view of the local bubble – the giant region of sparse gas, whose density is about one tenth of the average density of the interstellar medium. The solar system began to pass through a bubble about five million years ago and is currently in the center of the region.
On the bubble border, a variety of areas were found, where young stars are formed. The researchers found that there are almost all star-forming complexes from those that are in the vicinity of the Sun. Young stars move perpendicular to the surface of the bubble, which indicates the continued expansion of the boundaries of the region with a very low speed (about six kilometers per second).
Scientists believe that a surge of star formation near the present center led to the emergence of the bubble, and after – the death of massive stars about 14 million years ago. In other words, the powerful streams of stellar wind were influenced by the space environment, which then changed the shock wave from supernovae. The expansion of the local bubble led to the fact that the surrounding interstellar environment formed a shell, some parts of which were collapsed into dense molecular clouds.