Journey to the centre of our galaxy
Sagittarius A* is not the only mystery lurking in this part of the galaxy. The crowded centre contains numerous objects that are hidden at visible wavelengths by thick clouds of dust in the galaxy's disc. In order to truly understand the central part of our galaxy astronomers used the infrared vision of Hubble to peer through this obscuring dust. To reveal the image in all its glory the scientists then assigned visible colours to the different wavelengths of infrared light, which is invisible to human eyes.
Using Hubble's vantage point above the atmosphere and its high resolution, astronomers were able not only to reveal the stars in this cluster but also to measure their movements over a period of four years. Using this information, they inferred important properties of the nuclear star cluster, such as its mass and structure. The motion of the stars may also offer astronomers a glimpse into how the nuclear star cluster was formed—whether it was built up over time from globular star clusters that happened to fall into the centre of the galaxy, or from gas spiralling in from the Milky Way's disc to form stars at the core.
The data for this picture was gathered in September 2011 and is a mosaic stitched together from nine separate images taken with the Wide Field Camera 3 (WFC3).
Source: ESA/Hubble Information Centre [April 01, 2016]