What will the JWST tell us about our own Galaxy and those close by? How old are the stars in our Milky Way and its neighbours - and what do these stars tell us of their origins?
History of the Milky Way and its neighbours
Though the JWST will investigate the early Universe and the creation of the first galaxies, our understanding of this process would be incomplete without answering some of the most basic questions about the history of our own Galaxy and its neighbours.
The stars in our 'local' Universe represent a fossil record of the evolutionary and chemical history of our neighbourhood. The JWST will be able to read this fossil history for a large number of nearby galaxies, extending the work started by Hubble outwards significantly.
In addition to acting as a 'time machine' for the study of the most remote galaxies in the distant past, the JWST will also be able to decipher the history of our surroundings.
Deciphering this record is a difficult task and requires the brightness and colours of individual stars to be measured at great distances and in crowded regions. To completely understand the record of star formation in our galactic neighbourhood we must learn: