The combination of high resolution and infrared-detecting instruments on NASA's upcoming James Webb Space Telescope will reveal stars that are currently hidden even from the powerful Hubble Space Telescope. The wealth of additional star data will allow astronomers to investigate a range of questions, from star birth to star death to the universe's elusive expansion rate. Early observations with Webb will demonstrate its ability to distinguish the individual light of stars in the local universe in a range of environments and provide astronomers with tools for making the most of Webb's powerful capabilities.
"NASA's Hubble and Spitzer space telescopes have been transformative, opening the door to the infrared universe, beyond the realm of red visible light. Webb is a natural evolution of those missions, combining Spitzer's view of the infrared universe with Hubble's sensitivity and resolution," says Daniel Weisz of the University of California, Berkeley, the principal investigator on Webb's early release science (ERS) program on resolved populations of stars.
Webb's ability to resolve individual stars that are shrouded behind gas and dust in visible light will be applicable to many areas of astronomical research. The goals of this ERS program are to demonstrate Webb's capabilities in the local universe and create free, open-source data analysis programs for astronomers to make the best use of the observatory as quickly as possible. Data from the ERS programs will be available to other astronomers immediately, and archived for future research via the Barbara A. Mikulski Archive for Space Telescopes (MAST).
Insight into Dark Energy
Webb's ability to pick out details for more individual stars than we have seen before will improve distance measurements to nearby galaxies, which Weisz says will be crucial to one of the biggest mysteries of modern-day astronomy: How fast is the universe expanding? A phenomenon called dark energy seems to be driving this expansion. Various methods for calculating the expansion rate have resulted in different answers, discrepancies astronomers hope Webb's data can help reconcile.
"In order to do any of this science, calculating distances and then the universe's expansion rate, we need to be able to extract the light of individual stars from Webb images," Weisz says. "Our ERS program team will develop software that empowers the community to make those types of measurements."
