Using images from the Hubble Space Telescope, a bird's-eye panoramic view of part of the Andromeda galaxy is the clearest, largest picture ever assembled by NASA of the galaxy next door.
The Andromeda galaxy is located more than 2 million light-years away from Earth but the Hubble Space Telescope was powerful enough to capture part of it, bringing together 1.5 billion pixels representing a stretch of galaxy with a length of 61,000 light-years. Over 100 million stars were immortalized in the image as well, some of them seen in clusters of thousands.
The impressive photograph raises the bar for precision studies involving spiral galaxies dominating the universe as they number more than 100 billion. Astronomers have never been able to view stars so clearly yet so widespread in external spiral galaxies.
This image of the Andromeda galaxy marks the first close look humans have of glorious star cities. At the same time, data yielded from the photograph also sheds light on star populations within the context of their own home galaxy.
The Hubble Space Telescope traced tightly packed stars extending from the galaxy's innermost hub at the left. From the central bulge, the picture sweeps across, catching lanes of dust as well as stars before reaching the sparser outer disk.
Where young blue stars are grouped, clusters of stars and regions where stars form can be found in the picture. Toward the right side of the image, stars are bunching up, appearing like a blue ring-like feature. Complex structures of dust are represented by dark silhouettes while cooler red stars are distributed.
To create such an extensive image, the Panchromatic Hubble Andromeda Treasury program used 7,398 exposures across 411 individual pointings. With the Wide Field Camera 3 and the Advanced Camera for Surveys, images were captured at near-infrared, visible and near-ultraviolet wavelengths.
A cropped view of the galaxy 48,000 light-years in length was also produced, showing Andromeda in its natural visible color. This was possible by using blue and red filters on the Advanced Camera on Hubble.
The Hubble Space Telescope is a joint project between NASA and the European Space Agency (ESA). The Goddard Space Flight Center in Maryland is in charge of managing the telescope while the Space Telescope Science Institute conducts Hubble's science operations. The Association of Universities for Research in Astronomy operates the STScI for NASA.
The panoramic image of the Andromeda galaxy will be showcased at the 225th Meeting of the Astronomical Society.