The broken arm of the Milky Way

the bow arm It is one of the main four in our galaxy. They, like the other three, emerge from a central “rod”, and their curved structures give the appearance of a spiral about 100,000 light-years in diameter. But the spiral is less smooth than it looks, based on that part 5,000 light-years away from us, moving away from the main arm at about a 45-degree angle to the arm.

This segment is about 3,000 light-years across, and the motions of the stars seem to indicate a really distinct structure, not an optical illusion caused by the angle from which we view it, as the authors summarize.

This last point Underlined In general, because this structure includes astronomical phenomena known for a long time, such as Lagoon Nebula or that from eagle, but there is no observation that this part of the bow arm has so far evoked such a substructure that at this point it appears to be deviating from the intended axis. astronomers conjure In such conditions there is an observational bias: since we ourselves are inside this galaxy, it may be more difficult to spot such things there than we notice when we observe distant galaxies. which is to say That there must be other buildings of this type scattered throughout the “neighbourhood”.