A primordial galaxy in Cetus?
Cetus Dwarf Galaxy.
The Cetus dwarf galaxy is now thought to be like a brick – which might have gone into building a house – but instead was never used.
Astronomers discovered a dwarf galaxy in 1998 that now appears to be a leftover building block of big galaxies like our own Milky Way.
Astronomers think giant galaxies formed when smaller ones smashed together. The little ones are thought to be torn to pieces. So, it’s hard for astronomers to know what they once looked like. In contrast, the dwarf galaxy we just mentioned – located in the direction of the constellation Cetus – lies far from two big nearby galaxies. It’s 2.5 million light-years from our own Milky Way galaxy and nearly as far from the Andromeda galaxy.
If this dwarf galaxy had passed close to another larger galaxy, the encounter would have torn stars out of the dwarf. Astronomers don’t see these stars so they assume no such encounter has taken place. And that means the Cetus dwarf galaxy might be a pristine building block of big galaxies like our own.
It’s like a brick that might have gone into building a house, but was never used. This galaxy’s stars number in the millions – a far cry from the hundreds of billions of stars that throng the Milky Way. Yet astronomers believe that it’s from such humble building blocks that mighty galaxies like our own grew into giants.
Our thanks today to Research Corporation, a foundation for the advancement of science.
