Our Best Glimpse Yet Of The Andromeda Galaxy

Illustration for article titled Our Best Glimpse Yet Of The Andromeda Galaxy

You're looking at the biggest and sharpest image ever taken of the Andromeda Galaxy. Though it only includes one third of the massive celestial object, the image contains a jaw-dropping 1.5 billion pixels.


At that resolution, it would require more than 600 high-definition television screens to display the entire image. The full size original image is a whopping 4.3 GB. More reasonable, you can download the 5.3 MB JPEG or 138.8 KB JPEG.

The Hubble Space Telescope site explains more:

The large groups of blue stars in the galaxy indicate the locations of star clusters and star-forming regions in the spiral arms, whilst the dark silhouettes of obscured regions trace out complex dust structures. Underlying the entire galaxy is a smooth distribution of cooler red stars that trace Andromeda's evolution over billions of years.

The Andromeda Galaxy is a large spiral galaxy — a galaxy type home to the majority of the stars in the Universe — and this detailed view, which captures over 100 million stars, represents a new benchmark for precision studies of this galaxy type. The clarity of these observations will help astronomers to interpret the light from the many galaxies that have a similar structure but lie much further away.

Because the Andromeda Galaxy is only 2.5 million light-years from Earth it is a much bigger target on the sky than the galaxies Hubble routinely photographs that are billions of light-years away. In fact its full diameter on the night sky is six times that of the full Moon. To capture the large portion of the galaxy seen here — over 40 000 light-years across — Hubble took 411 images which have been assembled into a mosaic image.

Because of the enormous size of the image, Hubble has provided this zoom tool. Alternately, you can watch this video:

As an aside — and just to give you an idea of how close the Andromeda Galaxy is to Earth — this is what it would actually look like if it were considerably brighter.

Illustration for article titled Our Best Glimpse Yet Of The Andromeda Galaxy

Stephen Rahn/NASA/JPL-Caltch.

[ Hubble ]

Image credit: NASA, ESA, J. Dalcanton (University of Washington, USA), B. F. Williams (University of Washington, USA), L. C. Johnson (University of Washington, USA), the PHAT team, and R. Gendler.



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