Dans ce télescope spatial Hubble, UGCA 307 est suspendu sur un fond irrégulier de galaxies lointaines. Située dans la constellation de Corvus, à environ 26 millions d’années-lumière de la Terre, la petite galaxie se compose d’un amas clairsemé d’étoiles parsemées de bulles de gaz rouges qui indiquent des régions récemment formées d’étoiles. Crédit : ESA/Hubble & NASA, R. Tully
UGCA 307 est une petite galaxie irrégulière située à environ 26 millions d’années-lumière de la Terre dans la constellation de Corvus. Il fait partie du groupe local de galaxies qui comprend nos galaxies[{ » attribute= » »>Milky Way, and it is notable for its diffuse band of stars and red bubbles of gas that signify recent star formation. UGCA 307 is also sometimes referred to as the “Wolf-Lundmark-Melotte” galaxy, named after the astronomers who first discovered it.
UGCA 307 hangs against an irregular backdrop of distant galaxies in this image from the Hubble Space Telescope. The small galaxy consists of a diffuse band of stars containing red bubbles of gas that mark regions of recent star formation, and lies roughly 26 million light-years from Earth in the constellation Corvus. Appearing as just a small patch of stars, UGCA 307 is a diminutive dwarf galaxy without a defined structure — resembling nothing more than a hazy patch of passing cloud.
This image is part of a Hubble project to explore every known nearby galaxy, giving astronomers insights into our galactic neighborhood. Before this set of observations, almost three quarters of nearby galaxies had been investigated by Hubble in enough detail to spot the brightest stars and build up an understanding of the stars populating each galaxy. This Hubble project set out to explore the remaining quarter of nearby galaxies by taking advantage of short gaps in Hubble’s observing schedule.
This crystal-clear image was captured by Hubble’s Advanced Camera for Surveys (ACS), which was installed on the telescope in 2002 during Servicing Mission 3B. Hubble’s vantage point in low Earth orbit means that it is above atmospheric turbulence, giving it a sharper view of the Universe. However, it is also close enough to Earth that astronauts could visit the telescope to repair and refurbish the telescope. In total, five Space Shuttle missions flew to Hubble and kept it at the forefront of astronomy by installing new instruments. The ACS replaced one of Hubble’s original instruments, the Faint Object Camera, which was built by ESA.
