WEBVTT 1 00:00:03.399 --> 00:00:08.880 Welcome to Bedtime Astronomy. Explore the wonders of the cosmos with our soothing Bedtime 2 00:00:08.880 --> 00:00:14.759 Astronomy podcast. Each episode offers a gentle journey through the stars, planets, 3 00:00:14.800 --> 00:00:19.800 and beyond, perfect for unwinding after a long day. Let's travel through the 4 00:00:19.800 --> 00:00:23.519 mysteries of the universe as you drift off into a peaceful slumber under the night 5 00:00:23.559 --> 00:00:35.039 sky. Stellar Titans the colossal stars that light up the cosmos. The universe 6 00:00:35.159 --> 00:00:40.439 is a vast, mysterious expanse, filled with wonders that defy the imagination. 7 00:00:42.560 --> 00:00:47.719 Among these celestial marvels, the stars stand out as the most on, spiring 8 00:00:49.759 --> 00:00:54.960 from the smallest red dwarfs to the most colossal super giants, stars come in 9 00:00:55.000 --> 00:01:00.759 a dizzying array of sizes and temperatures. In this narrative, we embark on 10 00:01:00.799 --> 00:01:07.359 a journey to explore the biggest stars in the cosmos, comparing their immense sizes 11 00:01:07.400 --> 00:01:15.799 and scorching temperatures in understanding the cosmic phenomena that govern their existence. Our journey 12 00:01:15.840 --> 00:01:23.159 begins with an understanding of stellar classifications. Stars are categorized based on their spectral 13 00:01:23.280 --> 00:01:33.359 characteristics, primarily their temperature and luminosity. The hert Sprung Russell Hr diagram is 14 00:01:33.400 --> 00:01:38.799 a pivotal tool in this classification, plotting stars. According to these properties, 15 00:01:40.799 --> 00:01:45.640 stars ranged from the cool, dim red dwarfs to the hot, luminous blue 16 00:01:45.680 --> 00:01:53.560 supergiants. Our focus, however, is on the giants and supergiants, the 17 00:01:53.599 --> 00:02:00.000 behemoths of the stellar world. One of the most well known and studied supergiant 18 00:02:00.079 --> 00:02:07.560 and stars is Beetlejuice, located in the constellation Orion. Beetlejuice is a red 19 00:02:07.640 --> 00:02:15.439 supergiant nearing the end of its stellar life. Its diameter is staggering about one 20 00:02:15.479 --> 00:02:21.319 thousand times that of our Sun. If placed in the center of our solar 21 00:02:21.400 --> 00:02:28.639 system, Beetlejuice would extend beyond the orbit of Jupiter. Despite its immense size, 22 00:02:29.039 --> 00:02:35.479 Beetlejuice's surface temperature is relatively cool, around three thousand, five hundred kelvin. 23 00:02:37.439 --> 00:02:46.039 This cool temperature gives Beetlejuice its characteristic red hue. Comparatively, and Terry's, 24 00:02:46.560 --> 00:02:53.840 another red supergiant located in the constellation Scorpius, is equally impressive, and 25 00:02:53.960 --> 00:03:00.919 Terris is slightly smaller than Beetlejuice but still colossal, with a dieteameter approximately seven 26 00:03:01.039 --> 00:03:07.960 hundred times that of the Sun. Its surface temperature is also similar, about 27 00:03:08.039 --> 00:03:15.719 three thousand, four hundred kelvin. The sheer size of these stars is difficult 28 00:03:15.719 --> 00:03:21.199 to comprehend. Their outer layers are so diffuse that they appear almost like cosmic 29 00:03:21.280 --> 00:03:29.000 balloons. Moving to the constellation Canus major, we encounter vy Caanus Majories, 30 00:03:29.439 --> 00:03:36.360 one of the largest known stars by volume. This red hypergiant has an estimated 31 00:03:36.400 --> 00:03:40.680 diameter between one thousand, three hundred and one thousand, five hundred and forty 32 00:03:40.759 --> 00:03:46.599 times that of the Sun. If placed in the center of our solar system, 33 00:03:47.039 --> 00:03:54.120 it would engulf the orbit of Saturn. Vycanus Majories has a surface temperature 34 00:03:54.159 --> 00:04:00.439 of about three thousand, five hundred kelvin, similar to other red super giants. 35 00:04:01.439 --> 00:04:06.520 However, its mass is only seventeen times that of the Sun, highlighting 36 00:04:06.520 --> 00:04:13.879 the difference between size and mass in stellar terms. The next star on our 37 00:04:14.000 --> 00:04:20.160 journey is Ui scwty, located in the constellation Skewtum. Ui scwty is a 38 00:04:20.199 --> 00:04:26.600 red supergiant and is often cited as one of the largest stars known by radius. 39 00:04:28.600 --> 00:04:33.000 Its size is truly astronomical, with a diameter around one thousand, seven 40 00:04:33.079 --> 00:04:40.879 hundred times that of the Sun. Like the other red supergiants. Its surface 41 00:04:40.959 --> 00:04:46.560 temperature is relatively cool, approximately three thousand, three hundred and sixty five kelvin. 42 00:04:48.639 --> 00:04:54.879 Ui Scuty's luminosity is about three hundred and forty thousand times that of the 43 00:04:54.920 --> 00:05:00.759 Sun, baking it one of the brightest stars in our galaxy. While red 44 00:05:00.839 --> 00:05:08.720 supergiants dominate in size, the blue supergiants and hypergiants are equally fascinating for their 45 00:05:08.759 --> 00:05:15.639 extreme temperatures and luminosities. One such star as Rigel, located in Orion. 46 00:05:17.680 --> 00:05:23.959 Rigel is a blue supergiant with a diameter about seventy nine times that of the 47 00:05:24.000 --> 00:05:30.279 Sun, significantly smaller than the red supergiants, but its temperature is much higher, 48 00:05:30.720 --> 00:05:38.240 around eleven thousand kelvin. This high temperature gives Rigel its characteristic blue white 49 00:05:38.319 --> 00:05:46.199 color. Rigel is also incredibly luminous, shining with the brightness of approximately one 50 00:05:46.279 --> 00:05:54.240 hundred and twenty thousand suns. Another blue hypergiant, Ata Korine, located in 51 00:05:54.279 --> 00:05:59.120 the Carina constellation, is one of the most massive and luminous stars known. 52 00:06:00.120 --> 00:06:05.240 Its diameter is about sixty times that of the Sun, but its temperature source 53 00:06:05.319 --> 00:06:13.360 to around twenty thousand kelvin Ada Karini is also a part of a binary system, 54 00:06:13.759 --> 00:06:19.079 with its companion being a massive star as well. The combined luminosity of 55 00:06:19.120 --> 00:06:24.920 Ada Karini and its companion is about five million times that of the Sun. 56 00:06:26.879 --> 00:06:32.439 The intense radiation and stellar winds from Aida Karini creates spectacular nebulae, such as 57 00:06:32.480 --> 00:06:40.160 the Homunculus nebula, which surrounds the star. As we delve deeper into the 58 00:06:40.199 --> 00:06:45.120 realm of massive stars, we encounter Our one thirty six O one, a 59 00:06:45.199 --> 00:06:50.600 star located in the Tarantula nebula within the large Magellanic Cloud, a neighboring galaxy. 60 00:06:53.560 --> 00:06:57.600 Our one thirty six A one is a wolf rayate star, a type 61 00:06:57.639 --> 00:07:03.319 of massive star known for its high temper and powerful stellar winds. R one 62 00:07:03.519 --> 00:07:09.839 thirty six A one has a temperature of around fifty three thousand kelvin, making 63 00:07:09.879 --> 00:07:15.040 it one of the hottest stars known. Its mass is a staggering two hundred 64 00:07:15.079 --> 00:07:20.240 and fifteen times that of the Sun, and its luminosity is nearly nine million 65 00:07:20.319 --> 00:07:28.680 times greater. Despite its relatively small radius of about thirty five times that of 66 00:07:28.720 --> 00:07:32.600 the Sun. Our one thirty six A one's extreme mass and temperature make it 67 00:07:32.639 --> 00:07:41.399 a truly extraordinary object. The Pistol Star, located near the center of our 68 00:07:41.480 --> 00:07:47.519 Milky Way galaxy, is another blue hypergiant of note. This star is about 69 00:07:47.560 --> 00:07:54.040 one hundred times the diameter of the Sun and has a temperature of approximately twelve 70 00:07:54.040 --> 00:07:59.839 thousand kelvin. The Pistol Star is one of the most luminous stars now, 71 00:08:00.639 --> 00:08:05.959 with a brightness around one point six million times that of the Sun. Its 72 00:08:07.040 --> 00:08:11.800 name derives from the pistol nebula, a shell of gas and dust ejected by 73 00:08:11.839 --> 00:08:18.279 the star during a previous outburst. The blue hypergiant LBV eighteen oh six to 74 00:08:18.319 --> 00:08:26.199 twenty, located in the constellation Sagittarius, is another stellar colossus, with a 75 00:08:26.279 --> 00:08:31.559 diameter about two hundred times that of the Sun and a temperature of eighteen thousand 76 00:08:31.679 --> 00:08:37.960 kelvin. LBV eighteen oh six to twenty is also one of the most luminous 77 00:08:37.960 --> 00:08:43.759 stars known, radiating with the energy of forty million suns. This star is 78 00:08:43.879 --> 00:08:48.639 part of a dense star cluster and is surrounded by a complex network of gas 79 00:08:48.679 --> 00:08:56.559 and dust, providing a rich environment for astronomical study. One cannot discuss massive 80 00:08:56.600 --> 00:09:03.240 stars without mentioning the intriguing vs variable stars known as luminous blue variables. LBVs 81 00:09:05.279 --> 00:09:11.960 B stars undergo dramatic changes in brightness and size over relatively short periods of time. 82 00:09:13.919 --> 00:09:20.120 One of the most famous LBVs is ag Karini, located in the Korina 83 00:09:20.159 --> 00:09:26.879 constellation. Ag Karini has a diameter that can vary between fifty to five hundred 84 00:09:26.919 --> 00:09:33.720 times that of the Sun depending on its current state. Its temperature ranges from 85 00:09:33.759 --> 00:09:39.879 eight thousand to twenty five thousand kelvin, and its luminosity can reach up to 86 00:09:39.919 --> 00:09:46.080 a million times that of the Sun. The variability and instability of LBVs make 87 00:09:46.159 --> 00:09:52.639 them fascinating subjects for study, providing insights into the late stages of stellar evolution. 88 00:09:56.279 --> 00:10:01.559 While the aforementioned stars represent some of the largest and most luminous stars known, 89 00:10:01.039 --> 00:10:05.759 the universe is filled with countless other massive stars, each with its own 90 00:10:05.840 --> 00:10:13.600 unique properties and behaviors. The stars play a crucial role in the cosmic ecosystem, 91 00:10:13.879 --> 00:10:18.759 contributing to the chemical enrichment of the universe through the heavy elements they produce 92 00:10:18.960 --> 00:10:26.960 and disperse via supernovae. The study of massive stars also provides critical insights into 93 00:10:28.000 --> 00:10:33.080 the processes of star formation, stellar evolution, and the dynamics of galaxies. 94 00:10:35.039 --> 00:10:43.039 Comparing the sizes and temperatures of these colossal stars reveals the incredible diversity and complexity 95 00:10:43.120 --> 00:10:50.360 of the stellar world. The red supergiants, with their immense sizes and relatively 96 00:10:50.440 --> 00:10:56.919 cool temperatures, contrast sharply with the blue supergiants and hypergiants, which are smaller 97 00:10:56.919 --> 00:11:03.639 in size but much hotter and more luminous. This diversity is a testament to 98 00:11:03.679 --> 00:11:09.600 the varied pathways of stellar evolution driven by the mass, composition, and environmental 99 00:11:09.639 --> 00:11:16.840 conditions of the stars. Understanding the life cycles of these massive stars is essential 100 00:11:16.919 --> 00:11:24.960 for comprehending the broader processes that shape our universe. From their birth in dense 101 00:11:24.039 --> 00:11:31.240 molecular clouds to their violent deaths as supernova or gamma ray bursts, massive stars 102 00:11:31.399 --> 00:11:37.639 influence their surroundings in profound ways. Their deaths often result in the formation of 103 00:11:37.759 --> 00:11:45.200 neutron stars or black holes, further contributing to the dynamic and interconnected nature of 104 00:11:45.240 --> 00:11:54.039 the cosmos. The future of stellar astronomy promises even more discoveries and deeper insights 105 00:11:54.159 --> 00:12:01.200 into the nature of massive stars. Advanced telescopes and observdvories such as the James 106 00:12:01.240 --> 00:12:07.759 Webb Space Telescope and the Extremely Large Telescope, will enable astronomers to study these 107 00:12:07.799 --> 00:12:16.159 stars in unprecedented detail. These observations will enhance our understanding of stellar atmospheres, 108 00:12:16.639 --> 00:12:24.519 internal structures, and the interactions between stars and their environments. In conclusion, 109 00:12:24.960 --> 00:12:31.559 the biggest stars in the universe captivate our imagination and challenge our understanding of the 110 00:12:31.639 --> 00:12:39.399 cosmos. From the red supergiants like Beetlejuice and Ui Skewty to the blue hypergiants 111 00:12:39.559 --> 00:12:45.120 like Ada Karine and are one thirty six one B, stellar giants represent the 112 00:12:45.200 --> 00:12:52.080 extremes of size and temperature in the stellar world. Their study not only reveals 113 00:12:52.120 --> 00:12:58.120 the diversity and complexity of stars, but also provides critical insights into the fundamental 114 00:12:58.200 --> 00:13:03.960 processes that govern the universe. As we continue to explore and learn from these 115 00:13:05.039 --> 00:14:41.399 colossal stars, we deepen our appreciation for the vastness and wonder of the cosmos.