Image: Hubble probes colorful galaxy
This image displays a swirling spiral galaxy named NGC 2906.
The blue speckles seen scattered across this galaxy are clusters of massive, young stars, which emit hot, blue-tinged radiation as they burn through their fuel at an immense rate. The swaths of orange are a mix of older stars that have swollen and cooled, and low-mass stars that were never especially hot to begin with. Owing to their lower temperatures, these stars emit a cooler, reddish radiation.
This image of NGC 2906 was captured by the NASA/ESA Hubble Space Telescope's Wide Field Camera 3, an instrument installed on Hubble in 2009 during the telescope's final servicing mission. Hubble observed this galaxy on the hunt for fading light from recent occurrences of stellar explosions known as supernovae.