Which astronomers hitherto had hidden: The galaxy we inhabit is quite bent
The Milky Way has the shape of a curved spiral. This shows a detailed three-dimensional map of our home galaxy. On the outskirts, the galactic disc is bent upwards on one side and down on the other side. A Chinese-Australian research group led by Chen Xiaodian of the Chinese Academy of Sciences in Beijing presented the map in the journal Nature Astronomy.
Measurement of Cosmic Milestones
The researchers had determined the exact positions of 1339 special stars. The stars studied belong to the group Cepheids (pronounced Ke-feh iden), which is also called cosmic milestones. These stars light up to 100,000 times brighter than our sun and can therefore be viewed over long distances. Their brightness varies in a regular cycle whose length depends on the respective star's brightness.
This is a great way to determine their distance: Because of the rhythm of fluctuations, astronomers feel the absolute brightness of a Cepheid star and can thus calculate how far away he must be so that he can seem as light as observed on the earthly spell . In this way, the researchers in each Cepheid not only studied the exact position in the sky, but also its exact distance ̵
"We usually imagine that the spiral galaxies are relatively flat" co-authors Richard de Grijs from Macquarie University in Sydney said in a statement from his college. However, the map shows that the disc is inclined and twisted. As a cause, astronomers suspect a torque in the fluid's rotating massive inner tail disk. Such a curved spiral has been observed in about a dozen other galaxies, the researchers said. The shape of our winter street is therefore rare, but not unique. ( dpa )