Speaker 1: Welcome to Brainstuff, a production of iHeartRadio.
Speaker 2: Hey brain Stuff, Lauren vogel Bomb here with another classic
Speaker 2: episode from the archives. This one gets into astronomy research
Speaker 2: that has let us learn more about the shape of
Speaker 2: our Milky Way galaxy and why it's bent like a
Speaker 2: damaged vinyl record. Hey rain Stuff, Lauren vogel Bomb here.
Speaker 2: Imagine standing in a dense woodland. How would you know
Speaker 2: the size and shape of that forest? From your limited viewpoint?
Speaker 1: Not seeing the woods for the trees is a good
Speaker 1: analogy for what astronomer's experience when trying to assess the
Speaker 1: shape and size of our Milky Way galaxy. We occupy
Speaker 1: a small star system embedded inside the Milky Way's disc.
Speaker 1: It's not like we can fly above the galactic plane
Speaker 1: to peak at our galaxies overall shape, although how cool
Speaker 1: would that be. Our researchers, however, were determined to figure
Speaker 1: out the true shape of the Milky Way while staying
Speaker 1: embedded inside of it, and they have. Here's how they
Speaker 1: did it. A team from the National Astronomical Observance Tories
Speaker 1: of the Chinese Academy of Sciences that's the NAOC and
Speaker 1: Macquarie University in Australia studied the one thousand, three hundred
Speaker 1: and thirty nine bright pulsating stars called Cepheid variables to
Speaker 1: create a three D map of the disc of our galaxy.
Speaker 1: What they found came as a surprise. We live in
Speaker 1: a warped galaxy. Astronomer and research collaborator Richard de Grace
Speaker 1: said in a statement, Oh, we usually think of spiral
Speaker 1: galaxies as being quite flat, like Andromeda, which you can
Speaker 1: easily see through a telescope. But our galaxy isn't like Andromeda.
Speaker 1: It has an S shaped bend that gets more twisted
Speaker 1: the farther you move away from the galactic center. At
Speaker 1: this bend, the galaxy's gravitational poll becomes weaker, making it
Speaker 1: look like an old vinyl record that's become warped. The study,
Speaker 1: which has been published in the journal Nature Astronomy, used
Speaker 1: data from NASA's Wide Field Infrared Survey Explorer to precisely
Speaker 1: determine the locations of the cepheids throughout our galactic disc
Speaker 1: and turned them into a powerful tool to cut through
Speaker 1: the dust, gas, and other stars that are obscuring our view.
Speaker 1: Chen Xiadienne RENAOC and the lead author of the study,
Speaker 1: said in a press release, it's notoriously difficult to determine
Speaker 1: distances from the Sun two parts of the Milky Way's
Speaker 1: added 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. Cepheids 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 life span they make up
Speaker 1: or in regular pulses in brightness that can be used
Speaker 1: by 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 Way's warped spiral 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 is based on
Speaker 1: the article our Milky Way is Warped Like an old
Speaker 1: Vinyl record on HowStuffWorks dot.
Speaker 2: Com, written by Ian O'Neil. Brain Stuff is production by
Speaker 2: Heart Radio in partnership with how Stuffworks dot Com and
Speaker 2: is produced by Tyler Klaang. Four more podcasts my heart Radio,
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