Speaker 1: Welcome to brain stuff from how stuff works, Hey, brain Stuff.
Speaker 1: Lauren vogelbam here imagined standing in a dense woodland. How
Speaker 1: would you know the size and shape of that forest
Speaker 1: from your limited viewpoint? Not seeing the woods for the
Speaker 1: trees is a good analogy for what astronomer's experience when
Speaker 1: trying to assess the shape and size of our Milky
Speaker 1: Way galaxy. We occupy a small star system embedded inside
Speaker 1: the Milky Ways disc. It's not like we can fly
Speaker 1: above the galactic plane to peek at our galaxies overall shape,
Speaker 1: although how cool would that be. Researchers, however, were determined
Speaker 1: to figure out the true shape of the Milky Way
Speaker 1: while staying embedded inside of it, and they have. Here's
Speaker 1: how they did it. A team from the National Astronomical
Speaker 1: Observatories of the Chinese Academy of Sciences that's the n
Speaker 1: a o C and Macquarie University in Australia studied the
Speaker 1: one thousand, three D and thirty nine right pulsating stars
Speaker 1: called CEFIAD variables to create a three D map of
Speaker 1: the disc of our galaxy. What they found came as
Speaker 1: a surprise. We live in a warped galaxy. Astronomer and
Speaker 1: research collaborator Richard de Grace said in a statement, we
Speaker 1: usually think of spiral galaxies as being quite flat, like Andromeda,
Speaker 1: which you can easily see through a telescope. But our
Speaker 1: galaxy isn't like Andromeda. It has an S shaped bend
Speaker 1: that gets more twisted the farther you move away from
Speaker 1: the galactic center. At this bend, the galaxy's gravitational pull
Speaker 1: becomes weaker, making it look like an old vinyl record
Speaker 1: that's become warped. The study, which has been published in
Speaker 1: the journal Nature Astronomy, used data from NASA's Wide Field
Speaker 1: Infrared Survey Explorer to precisely determine the locations of the
Speaker 1: cepheids throughout our galactic disc and turned them into a
Speaker 1: powerful tool to cut through the dust, gas, and other
Speaker 1: stars that are ob scaring our view. Cheniadene, a researcher
Speaker 1: at n AOC and the lead author of the study,
Speaker 1: set in a press release it's notoriously difficult to determine
Speaker 1: distances from the Sun two parts of the Milky Ways
Speaker 1: outer gas disc without having a clear idea of what
Speaker 1: the disc actually looks like. However, we recently published a
Speaker 1: new catalog of well behaved variable stars known as classical cepheids,
Speaker 1: for which distances as accurate as three to five percent
Speaker 1: can be determined. Sepheids are young stars that are four
Speaker 1: to twenty times the mass of our Sun, and they
Speaker 1: live fast and die young, consuming all their fuel in
Speaker 1: the span of only a few million years, all while
Speaker 1: burning up to one hundred thousand times brighter than our star.
Speaker 1: But what they lack in lifespan they make up or
Speaker 1: in regular pulses in brightness that can be used by
Speaker 1: astronomers to accurately measure their distances, and in this case,
Speaker 1: they acted as tracers to map out the warped milky
Speaker 1: Way disc. Although the milky Way doesn't conform to the
Speaker 1: standard flat disc exhibited by other spiral galaxies like Andromeda,
Speaker 1: it's not alone. From earlier observations, the researchers identified a
Speaker 1: dozen other galaxies with a similar S shaped bend, which
Speaker 1: have given them a clue as to why our galaxy
Speaker 1: is warped. Blue Chow, co author of the study, said,
Speaker 1: combining our results with those other observations, we concluded that
Speaker 1: milky ways warped spival pattern is most likely caused by
Speaker 1: torques or rotational forcing by the massive inner disc. Basically,
Speaker 1: the orbital motions in the massive central region of the
Speaker 1: Milky Way gravitationally bully the less massive outer regions, causing
Speaker 1: them to buckle and bend out of shape. Ultimately, this
Speaker 1: new finding could help us better understand the dynamics of
Speaker 1: orbital motions inside the Milky Way, thereby providing a glimpse
Speaker 1: of how our galaxy evolved. Today's episode was written by
Speaker 1: Ian O'Neil and produced by Tyler Clang for iHeart Media
Speaker 1: and How Stuff Works. For more on this and lots
Speaker 1: of other warped topics, visit our home planet, how stuff
Speaker 1: works dot com.