# Transcript of Roman Time Domain_Galactic Bulge Survey

 00;00;00;00 - 00;00;01;16 [Music throughout]  00;00;01;16 - 00;00;03;17 Almost all observations of the universe 00;00;03;17 - 00;00;06;17 come by collecting light in various wavelengths. 00;00;06;22 - 00;00;09;17 This light can show variations in brightness, 00;00;09;17 - 00;00;14;10 reveal structure in cosmic objects, and contain huge amounts of information 00;00;14;10 - 00;00;18;13 in how its wavelengths are distributed across a spectrum. 00;00;18;16 - 00;00;23;00 Researchers have captured these details for decades, even centuries. 00;00;23;03 - 00;00;27;21 But often they are limited to just a brief snapshot of an object in space. 00;00;27;24 - 00;00;29;18 A single still image. 00;00;30;04 - 00;00;31;10  In recent years, 00;00;31;12 - 00;00;36;06 scientists have been making more observations with a fourth component: time. 00;00;36;13 - 00;00;41;00 Space isn't static, and recording data through a given duration called  00;00;41;00 - 00;00;45;14 Time-Domain Astronomy tracks how details of an object like brightness, 00;00;45;14 - 00;00;50;18 spectrum, location and structure change. An object can vary, 00;00;50;23 - 00;00;53;15 it can move, or it can do both. 00;00;53;15 - 00;00;57;13 There are three main classes of how an object can vary in time. 00;00;57;15 - 00;01;02;06 Periodic, quasiperiodic, and transient. Periodic change 00;01;02;06 - 00;01;05;22 means there is a regular fixed pattern to the change. 00;01;05;25 - 00;01;09;26 Sunrise and sunset or a blinking pulsar are examples. 00;01;09;29 - 00;01;13;03 Quasiperiodic means that there is a pattern and the change 00;01;13;03 - 00;01;16;06 or event happens again and again, but not as regularly, 00;01;16;09 - 00;01;20;20 like hurricanes or flashes from hot material around black holes. 00;01;20;23 - 00;01;24;23 Transient events are less predictable and often happen only once. 00;01;25;01 - 00;01;27;23 Earthquakes and supernovas are transients. 00;01;27;23 - 00;01;32;05 These are the hardest to observe because they can be brief and start unexpectedly. 00;01;32;08 - 00;01;35;24 If telescopes aren't looking in the right place, they miss the beginning or 00;01;35;24 - 00;01;37;23 even the entire event. 00;01;38;16 - 00;01;39;18 NASA's upcoming 00;01;39;18 - 00;01;42;26 Nancy Grace Roman Space Telescope will be specially equipped 00;01;42;26 - 00;01;46;08 to be a groundbreaking tool for Time-Domain Astronomy. 00;01;46;11 - 00;01;49;28 It will observe from space so it won't have daily time restrictions 00;01;49;28 - 00;01;53;11 like ground based telescopes, which can only observe at night. 00;01;53;14 - 00;01;56;23 It will have image quality like Hubble, but with a field of view 00;01;56;23 - 00;01;58;15 at least 100 times larger. 00;01;58;15 - 00;02;03;15 So it will be able to observe large portions of the sky all at once. 00;02;03;18 - 00;02;07;05 Roman is a survey mission, which means that in addition to a large, 00;02;07;05 - 00;02;08;23 singular field of view, 00;02;08;23 - 00;02;12;15 Roman can repoint that view more efficiently during observation 00;02;12;15 - 00;02;18;14 periods, tiling even larger areas of sky 1000 times faster than Hubble. 00;02;18;17 - 00;02;21;16 For one of these, called the Galactic Bulge Survey, 00;02;21;16 - 00;02;25;16 Roman will aim its expansive view at the center of our galaxy 00;02;25;19 - 00;02;29;18 and observe a two-square-degree region in infrared wavelengths 00;02;29;18 - 00;02;34;06 that cut through the obscuring dust to reveal millions of stars. 00;02;34;09 - 00;02;36;29 During this survey, Roman will take a new image 00;02;36;29 - 00;02;41;23 every 2 minutes for more than 62 days and then repeat this six times over 00;02;41;23 - 00;02;45;24 five years for a total of 400 days of coverage. 00;02;45;27 - 00;02;50;09 Roman will be watching for planets transiting, or eclipsing, their host stars 00;02;50;15 - 00;02;54;16 and rare gravitational lensing events where the gravity of foreground objects 00;02;54;16 - 00;02;58;24 lenses the light of background stars causing changes in brightness. 00;02;58;27 - 00;03;03;04 These peaks can reveal new planetary systems, rogue planets 00;03;03;04 - 00;03;07;19 untethered to a star, and even black holes that would otherwise be invisible. 00;03;07;22 - 00;03;10;22 A single snapshot of the sky can't show these events; 00;03;10;29 - 00;03;15;18 they require constant or very regular monitoring to reveal. 00;03;15;21 - 00;03;20;24 Roman’s main objective in this survey is simply finding new planets and black holes. 00;03;20;27 - 00;03;24;15 Astronomers anticipate that Roman could discover over 1,000 00;03;24;15 - 00;03;29;19 microlensing and 100,000 transiting planets from this survey alone. 00;03;29;22 - 00;03;32;11 Observatories like the James Webb Space Telescope 00;03;32;11 - 00;03;35;20 can then follow up with a narrower, more targeted view 00;03;35;25 - 00;03;40;04 and learn key details about the most interesting discoveries. 00;03;40;07 - 00;03;44;23 Roman will also perform time-oriented surveys  aimed at furthering our 00;03;44;23 - 00;03;50;19 understanding of the universe's history and future. With its wide and steady gaze, 00;03;50;22 - 00;03;57;10 the Nancy Grace Roman Space Telescope will be a key player in the future of Time Domain Astronomy. 00;04;01;16 - 00;04;06;15 [NASA]