About 260 light years long, and made of cold gas and dust, it is more than just a spectacular feature in our galaxy.
The beads hold an important secret. They are the birthplace of very big stars, research shows.
Advertisement: Story continues below Jill Rathborne, of CSIRO Astronomy and Space Science, said little was known about how massive stars, more than eight times the size of our sun, are formed.
''There are not very many of them and they don't live very long, so they are very hard to study,'' she said.
But these giants have an important effect on galaxies, emitting large amounts of radiation and stellar winds.
They forge heavy elements, and produce massive supernovae when they finally explode and die.
''If we have a better understanding of how stars form, we can look at how solar systems form and we can search for other solar systems like ours, and look for life,'' Dr Rathborne said.
She is a member of an international team that spotted the long, dark structure in the Milky Way using the NASA Spitzer Space Telescope.
They dubbed it the ''Nessie nebula''. ''It looks a bit like the Loch Ness monster,'' she said.
They then used CSIRO's Mopra radio telescope near Coonabarabran in NSW to take a detailed look at it, and their results are published in The Astrophysical Journal Letters.
''We found the concentration of gas and dust along Nessie is periodically spaced, like beads on a string,'' she said.
Observations of the beads revealed stars in the very early stages of life.
''We think it is where the next generation of massive stars will form,'' she said.
The large bright blobs at either end of the necklace are where very big stars have already developed and blown gigantic holes in the gas and dust.