The Andromeda galaxy is one of the most commonly studied objects in the night sky. It's just 2.5 million light years from Earth, is visible to the naked eye on a moonless night and has been imaged countless times. Japan's Subaru Telescope's Hyper Suprime-Cam (HSC) has provided the latest snap of the popular object, showing our neighboring galaxy in a spectacular new light.
The HSC was constructed by the National Astronomical Observatory of Japan in collaboration with a range of international industrial and academic partners such as the University of Tokyo and Princeton University.
It features a large 8.2-meter (27-ft) primary mirror and large field of view (1.5 degrees), providing a consistently high-quality resolution of the objects throughout the frame. The telescope's camera is significantly taller than the average human being and weighs around three tons.
The images produced by the HSC provide precise measurements of the brightness, shape and position of galaxies and stars, and demonstrate a field of view seven times that of the telescope's predecessor, the Subaru Prime Focus Camera (Suprime-Cam).
The new image of the Andromeda galaxy, also known as M31, is a significant milestone for the team. “This first image from HSC is truly exciting," says Dr. Masahiro Takada, the chair of the HSC science working group. "We can now start the long-awaited, largest-ever galaxy survey for understanding the evolutionary history and fate of the expanding Universe.”
The completion and installation of the HSC's major components was completed in August 2012. This image is the first part of a “cosmic census” designed to survey both the causes of the accelerating expansion of the Universe, and the properties and parameters of dark matter and dark energy.
Other images of M31
M31 is one of the best known galaxies in the universe and has been imaged various times in the past. By collecting light from the galaxy at different wavelengths, significantly different portraits of the object have emerged.
NASA's Spitzer Space Telescope has captured several images of M31. This 2005 infrared view of the famous galaxy reveals the object's prominent ring of stars formation, not clearly distinguishable in visible light images.
NASA's Galaxy Evolution Explorer (GALEX) space telescope produced this ultraviolet portrait of the object in 2008, stitching it together from 10 separate images.
Lastly, here's an ultraviolet and infrared composite image of the galaxy, taken from NASA's Galaxy Evolution Explorer and the Spitzer Space Telescope in 2006.
On a collision course
Not only is M31 the closest neighboring galaxy to the Milky Way, but according to Hubble measurements released last year, the gigantic object is actually on a collision course with our own galaxy.
However, the impact isn't expected to occur for around four billion years and will last for a further three billion years, culminating in the creation of a single large elliptical galaxy.
Source: NAOJ