Using the Wide Field Imager on the 2.2-m MPG/ESO telescope at ESO’s La Silla Observatory, Chile, astronomers have captured a new image of a nearby small galaxy known as the Sculptor Dwarf.
This image shows the Sculptor Dwarf Galaxy, a close neighbor of our own Milky Way Galaxy. Despite their proximity, both galaxies have very distinct histories and characters. This galaxy is much smaller, fainter and older than the Milky Way and appears here as a cloud of faint stars filling most of the image. Many other much more distant galaxies can be seen shining right through the sparse stars of the galaxy. Image credit: ESO.
The Sculptor Dwarf Galaxy, also known as the Sculptor Dwarf Elliptical or the Sculptor Dwarf Spheroidal, is a dwarf spheroidal galaxy located in the constellation Sculptor. It is approximately 261,000 light-years away from Earth.
This faint galaxy should not be confused with the much brighter Sculptor Galaxy, otherwise known as NGC 253, in the same constellation.
The Sculptor Dwarf is one of our Milky Way’s neighboring dwarf galaxies. However, it is much smaller and older than our Galaxy.
Despite its proximity, the galaxy was only discovered in 1937, as its stars are faint and spread thinly across the sky.
The galaxy’s shape intrigued astronomers at the time of its discovery, but nowadays dwarf spheroidals play a more important role in allowing scientists to dig deeply into the Universe’s past.
Our Milky Way Galaxy, like all large galaxies, is thought to have formed from the build-up of smaller galaxies during the early days of the Universe. If some of these dwarf galaxies still remain today, they should now contain many extremely old stars.
The Sculptor Dwarf Galaxy fits the bill as a primordial galaxy, thanks to a large number of ancient stars, visible in this image.
This quantity of aged stars makes the galaxy a prime target for studying the earliest periods of star formation.
In a recent study, astronomers combined all the data available for the galaxy to create the most accurate star formation history ever determined for a dwarf spheroidal galaxy.
This analysis revealed two distinct groups of stars in the galaxy. The first, predominant group is the older population, which is lacking in heavier elements. The second, smaller population, in contrast, is rich with heavy elements.
