WEBVTT 1 00:00:00.440 --> 00:00:03.480 This is Spacetime Series twenty nine, episode ninety four, for 2 00:00:03.600 --> 00:00:07.120 broadcast on the seventh of August twenty twenty six. Coming 3 00:00:07.200 --> 00:00:10.320 up on Space Time, it turns out black holes are 4 00:00:10.320 --> 00:00:13.839 a hundred times more powerful than previously thought. The dramatic 5 00:00:13.880 --> 00:00:17.760 collision which flipped our Milky Way galaxy and a successful 6 00:00:17.879 --> 00:00:20.199 return to Worth for the crew of the Sawyers M 7 00:00:20.199 --> 00:00:24.679 twenty eight. All that and more coming up on space Time. 8 00:00:25.839 --> 00:00:38.840 Welcome to Space Time with Stewart Gary. 9 00:00:45.039 --> 00:00:47.719 Astronomers have been forced to rewrite their textbooks on the 10 00:00:47.759 --> 00:00:51.000 power of supermassive black holes after new observations have shown 11 00:00:51.039 --> 00:00:54.640 that these cosmic monsters can generate enough energy to impact 12 00:00:54.640 --> 00:00:58.840 galaxies hundreds of thousands of light years away. Scientists previously 13 00:00:58.880 --> 00:01:02.039 believe that the impact of winds generated by super massive 14 00:01:02.039 --> 00:01:05.400 black holes was contained to the host galaxy, but the 15 00:01:05.480 --> 00:01:08.840 new findings reported in the General Nature Astronomy, reveals that 16 00:01:08.879 --> 00:01:12.319 the energy produced extends to surrounding galaxies three hundred thousand 17 00:01:12.400 --> 00:01:15.400 light years away, one hundred times further than previously thought. 18 00:01:15.920 --> 00:01:19.879 The studies lead author Satashi Yomta from Tohoku University says 19 00:01:19.920 --> 00:01:24.439 the discovery demonstrates that these explosive winds impact vast expanses 20 00:01:24.480 --> 00:01:28.359 of space far beyond the galaxies they inhabit. It Mata says. 21 00:01:28.400 --> 00:01:30.799 Black holes are largely known for sucking in matter, but 22 00:01:30.840 --> 00:01:33.760 they also eject gas in the form of powerful winds. 23 00:01:34.359 --> 00:01:37.120 These winds were thought to be contained within the galaxy, 24 00:01:37.280 --> 00:01:40.280 but your Madas study reveals the force is immensely more 25 00:01:40.319 --> 00:01:43.799 powerful than previously understood. Your matter and colleagues use the 26 00:01:43.840 --> 00:01:47.000 CHRISM X ray space telescope to observe the activity of 27 00:01:47.000 --> 00:01:50.079 a quaser cataloged as H eighteen twenty one plus six 28 00:01:50.239 --> 00:01:53.000 forty three, located some three point four billion light years 29 00:01:53.000 --> 00:01:56.799 away in the direction of the constellation. Draco. Quasars are 30 00:01:56.840 --> 00:02:00.599 extremely luminous jets of energy and matter given off material 31 00:02:00.680 --> 00:02:03.400 being crushed and stretched in the accretion disk of feeding 32 00:02:03.439 --> 00:02:07.120 black holes. The rapidly growing black hole containing the quasa 33 00:02:07.280 --> 00:02:09.800 is located in the center of a galaxy caster, where 34 00:02:09.800 --> 00:02:12.879 it's driving turbulence and the surrounding hot gas emitting X 35 00:02:12.960 --> 00:02:16.800 rays in the process. The authors precisely determine the motion 36 00:02:16.919 --> 00:02:20.960 of the gas by analyzing spectroscopic emission lines from iron ions. 37 00:02:21.520 --> 00:02:24.560 The observations revealed that the high temperature gas surrounding the 38 00:02:24.599 --> 00:02:28.159 black hole isn't remaining static, but violently disperses over a 39 00:02:28.199 --> 00:02:31.560 wide area due to turbulence, and they also confirm that 40 00:02:31.599 --> 00:02:34.479 the flow of the gas extends far beyond the host galaxy, 41 00:02:34.599 --> 00:02:37.520 reaching distances of more than three hundred thousand light years. 42 00:02:38.039 --> 00:02:40.759 The amount of energy involved in the turbulence was approximately 43 00:02:40.759 --> 00:02:43.680 one hundred times greater than what previous estimates had made, 44 00:02:43.879 --> 00:02:47.759 and equivalent to several billion supernova explosions, the blasts that 45 00:02:47.800 --> 00:02:50.759 occur when stars reach the end of their lives. You 46 00:02:50.840 --> 00:02:53.400 might have says. It's the first time anyone has shown 47 00:02:53.400 --> 00:02:56.360 that black holes can influence such a broad cosmic environment, 48 00:02:56.520 --> 00:02:59.479 and it demonstrates that black holes are key drivers of 49 00:02:59.520 --> 00:03:03.280 gas flow and motion in space, transporting vast amounts of 50 00:03:03.400 --> 00:03:07.840 energy materials to very distant regions of the cosmos. This 51 00:03:07.919 --> 00:03:11.719 is space time still to come. The dramatic collision that 52 00:03:11.759 --> 00:03:14.919 flipped our Milky Way galaxy and a successful return to 53 00:03:14.960 --> 00:03:17.879 Earth for the crew of the Sawyer's M twenty eight spacecraft. 54 00:03:18.159 --> 00:03:21.159 All that and more still to come on space time. 55 00:03:37.280 --> 00:03:40.199 A new study suggest that our home galaxy, the Milky Way, 56 00:03:40.400 --> 00:03:43.400 may have undergone a dramatic change in orientation following a 57 00:03:43.439 --> 00:03:47.280 head on collision with another galaxy. The findings, reported to 58 00:03:47.280 --> 00:03:50.560 the Royal Astronomical Society's conference in Birmingham, help us explain 59 00:03:50.680 --> 00:03:56.080 a long standing mystery about our galaxy. Using supercomputer simulations 60 00:03:56.120 --> 00:03:59.360 of galaxies like the Milky Way, astronomers found that galaxies 61 00:03:59.400 --> 00:04:02.639 with slowly rotating stellar halos are more likely to have 62 00:04:02.719 --> 00:04:05.919 experienced a major disc flip. That's where the galaxy's disc 63 00:04:06.080 --> 00:04:09.560 changes its orientation by more than ninety degrees. Most of 64 00:04:09.599 --> 00:04:12.560 the Milky Way stars are located in the flat spiral 65 00:04:12.639 --> 00:04:15.639 disc of the galaxy, and surrounding this disc is a 66 00:04:15.719 --> 00:04:19.120 much larger but spars stellar halo, made up mostly of 67 00:04:19.199 --> 00:04:22.240 stars that are originally formed in smaller galaxies before being 68 00:04:22.240 --> 00:04:26.439 pulled into the Milky Way through galactic mergers. Observations by 69 00:04:26.439 --> 00:04:29.199 the European Space Agency's Guian mission have shown that the 70 00:04:29.240 --> 00:04:33.120 Milky Way stellar halo rotates very slowly, but astronomers have 71 00:04:33.199 --> 00:04:37.480 not understood why. So they analyze the evolution of twenty 72 00:04:37.519 --> 00:04:40.560 five Milky Way like spiral galaxies in the rigious squid 73 00:04:40.600 --> 00:04:44.519 of cosmological computer simulations, and they followed their development over 74 00:04:44.639 --> 00:04:48.199 billions of years. They found that galaxies with the slowest 75 00:04:48.319 --> 00:04:52.560 rotating stellar haloes shared two important features. Each experienced a 76 00:04:52.600 --> 00:04:55.360 major head on merger or collision with another galaxy, and 77 00:04:55.439 --> 00:04:59.199 they also underwent a disc flip during their revolution. The 78 00:04:59.279 --> 00:05:03.519 studies lead author Kirol Batrikov from Durham University says astronomers 79 00:05:03.519 --> 00:05:05.800 already know that the Milky Way had a massive head 80 00:05:05.800 --> 00:05:07.959 on collision in the past with a galaxy known as 81 00:05:08.000 --> 00:05:11.360 the Guy Sausage and Soladus, and this new data suggests 82 00:05:11.399 --> 00:05:14.040 that may have caused the Milky Way's disc to flip. 83 00:05:14.600 --> 00:05:17.360 The Guy of Sausage and Soladus was a massive dwarf 84 00:05:17.399 --> 00:05:20.000 galaxy that collided with and was absorbed into the early 85 00:05:20.040 --> 00:05:23.279 milky Way somewhere around ten to eleven billion years ago. 86 00:05:23.839 --> 00:05:27.319 This defighting galactic merger was the largest single event in 87 00:05:27.319 --> 00:05:30.000 the early history of the Milky Way, and it reshaped 88 00:05:30.000 --> 00:05:33.360 our galaxy, leaving billions of stars orbiting in a highly 89 00:05:33.360 --> 00:05:38.199 elongated sausage shaped path. Identifying a past disc flip gives 90 00:05:38.199 --> 00:05:41.600 astronomers a new way to understand how the Milky Way assembled, 91 00:05:41.680 --> 00:05:44.360 and it may also provide indirect clues that the motion 92 00:05:44.439 --> 00:05:48.079 of its invisible dark matter halo. A disc clip also 93 00:05:48.160 --> 00:05:50.600 means most of the Milky Way stars moved on very 94 00:05:50.600 --> 00:05:54.120 different trajectories compared to the way they moved today, possibly 95 00:05:54.160 --> 00:05:56.879 even our own son Any our stable spot in the 96 00:05:56.920 --> 00:05:59.920 galaxy might not have been quite so stable in the past. 97 00:06:01.240 --> 00:06:03.639 The study also found that the rotation of the Milky 98 00:06:03.639 --> 00:06:06.560 Way stellar halo is closely linked to the rotation of 99 00:06:06.600 --> 00:06:10.199 its dark matter halo, and that suggests the two possibly 100 00:06:10.199 --> 00:06:12.959 evolve together as the galaxy grew by a creation of 101 00:06:13.000 --> 00:06:18.199 the smallst satellite galaxies. This is space time still to come. 102 00:06:18.600 --> 00:06:20.680 A successful return to Earth for the crew of the 103 00:06:20.680 --> 00:06:25.360 Sawyers M twenty eight. The red super giant antaries, Barnard Star, 104 00:06:25.480 --> 00:06:28.240 the second Earestar system to the Sun, and the annual 105 00:06:28.240 --> 00:06:31.600 Percied's meteor shower are among the highlights of the August 106 00:06:31.720 --> 00:06:50.240 night skies on SkyWatch. The ros Cosmos Sawyers M twenty 107 00:06:50.240 --> 00:06:53.120 eight spacecraft has returned safely to Earth, bringing home the 108 00:06:53.160 --> 00:06:55.879 expedition seventy four crew who were spent the past eight 109 00:06:55.920 --> 00:06:59.759 months aboard the International Space Station. The capsule touchdown of 110 00:06:59.759 --> 00:07:02.040 the world in script Kazakhstan stick three and a half 111 00:07:02.079 --> 00:07:04.120 hours after the patting the over the outpost. 112 00:07:04.319 --> 00:07:07.399 We are covering the return of the Suyu's MS twenty 113 00:07:07.439 --> 00:07:11.120 eight spacecraft with NASA astronaut Chris Williams and Ross Cosmos 114 00:07:11.160 --> 00:07:16.360 cosmonauts Sergei Kodsvirzkov and Sergei Mikhaye, returning under its main parachute, 115 00:07:16.480 --> 00:07:19.560 slowing it down for a touchdown on Earth. We did 116 00:07:19.639 --> 00:07:22.800 hear confirmation from the crew that everything was nominal or 117 00:07:22.839 --> 00:07:25.720 as expected on board. That's so us MS twenty eight 118 00:07:25.759 --> 00:07:29.079 spacecraft suspended under the orange and white parachute, and that 119 00:07:29.160 --> 00:07:32.680 main parachute covering an area of one thousand meters. It's 120 00:07:32.680 --> 00:07:36.480 slowing the capsule down to about sixteen miles per hour, 121 00:07:36.920 --> 00:07:39.879 quite a contrast from the seventeen thousand, five hundred miles 122 00:07:39.920 --> 00:07:42.920 per hour this crew was traveling just three hours ago. 123 00:07:43.079 --> 00:07:45.480 You course is how do papy me? I am? This 124 00:07:45.600 --> 00:07:48.920 is quesche Yas was pretty much us. We read you 125 00:07:49.000 --> 00:07:49.680 loud and clear. 126 00:07:52.560 --> 00:07:58.680 I love my space kid, but its. 127 00:08:00.199 --> 00:08:04.920 Ballistic myths is for seconds. We are in the controlled 128 00:08:05.319 --> 00:08:19.399 automatic descent. We see you, guys, uh one feeling great, creature, 129 00:08:19.560 --> 00:08:27.240 two feeling good, three feeling amazing. That is good news, guys. 130 00:08:28.199 --> 00:08:31.079 Confirmation from the crew themselves that they are are all 131 00:08:31.160 --> 00:08:34.919 feeling good, great and amazing. The crew also has a 132 00:08:35.000 --> 00:08:38.039 voice and visual with the search and recovery forces. Russian 133 00:08:38.279 --> 00:08:41.679 Search and Recovery at vs continue making their way towards 134 00:08:41.720 --> 00:08:43.480 the anticipated landing site. 135 00:08:52.600 --> 00:09:02.320 Cious search and rescue forces. What's your altitude? 136 00:09:02.399 --> 00:09:03.240 Thirty start for them? 137 00:09:03.720 --> 00:09:09.879 Our altitude is three kilometers seven fifty meters. Oxidizer jobs 138 00:09:09.919 --> 00:09:10.320 figure on. 139 00:09:10.399 --> 00:09:13.000 Matter, I apprecail a point at you. 140 00:09:16.399 --> 00:09:22.639 As the crew continues drifting down to Earth under that parachute. 141 00:09:21.840 --> 00:09:25.759 The aiometric altitude on the INPU panel is three kilometers. 142 00:09:25.919 --> 00:09:29.159 The next major milestone, and essentially the final milestone just 143 00:09:29.200 --> 00:09:32.360 before landing, is the soft landing engine firing says when 144 00:09:32.519 --> 00:09:35.679 six engines will fire to slow the descent rate to 145 00:09:35.879 --> 00:09:38.600 one point five meters per second, so just over three 146 00:09:38.679 --> 00:09:41.240 miles an hour when soy US is less than one 147 00:09:41.279 --> 00:09:44.559 meter above the ground. So the spacecraft now traveling about 148 00:09:44.600 --> 00:09:48.399 sixteen miles per hour ahead of those soft landing engines 149 00:09:48.440 --> 00:09:51.679 that fire just before touchdown to help ease the return 150 00:09:51.720 --> 00:09:59.879 to Earth. And a reminder that radio beacon that you 151 00:10:00.279 --> 00:10:04.879 is completely normal. This is establishing communications that begon coming 152 00:10:04.879 --> 00:10:08.240 from the spacecraft. You're hearing communications to and from the 153 00:10:08.360 --> 00:10:11.480 SWAYUS MS twenty eight spacecraft. Once you're hearing that of 154 00:10:11.519 --> 00:10:16.000 Commander Sergei Kidsfirzkov Ross Cosmos cosmonauts speaking with the mission 155 00:10:16.080 --> 00:10:25.960 control team in Moscow again. Conditions at the landing site. 156 00:10:26.080 --> 00:10:29.120 Visibility about six miles with twenty four mile per hour 157 00:10:29.159 --> 00:10:31.639 winds and eighty eight degrees fahrenheit. 158 00:10:37.639 --> 00:10:40.799 This is questions. I'm getting to nine hundred meters, hold 159 00:10:40.840 --> 00:10:43.679 your arms close to the body and please. 160 00:10:43.440 --> 00:10:46.519 Do not speak your globo docture and. 161 00:10:46.759 --> 00:10:49.039 This is going to stay true all the way and 162 00:10:49.080 --> 00:10:50.120 still handing. 163 00:10:50.080 --> 00:10:53.639 Landing now less than thirty seconds away. Crew receiving final 164 00:10:53.679 --> 00:10:55.159 instructions as they prepare for. 165 00:10:55.200 --> 00:10:58.240 Touchdown reference altitude, braceful landing. 166 00:11:04.240 --> 00:11:08.159 Touchdown. Chris Williams, Sergei Mikaev, and Sergi Kispertzhkov have returned 167 00:11:08.200 --> 00:11:10.960 to their home planet at five twenty seven am Central 168 00:11:11.000 --> 00:11:18.799 time three twenty seven pm in Kazakhstanzois. 169 00:11:16.519 --> 00:11:20.879 Is on its side and there is no fire. That's 170 00:11:21.759 --> 00:11:27.039 the rescue force is reporting all right, and the helicopters 171 00:11:27.360 --> 00:11:28.840 approaching to land. 172 00:11:28.919 --> 00:11:31.000 So I heard the call that the Soyus is on 173 00:11:31.080 --> 00:11:34.360 its side. This is not uncommon for the Soyuz, and 174 00:11:34.399 --> 00:11:37.960 the crew will be extracted from the spacecraft upon the 175 00:11:38.480 --> 00:11:40.519 recovery forces arriving at the capsule. 176 00:11:40.840 --> 00:11:43.279 The two hundred and forty one day mission launched from 177 00:11:43.320 --> 00:11:45.399 the Bike and or Cosmo drove and the Central Asian 178 00:11:45.399 --> 00:11:48.360 Republic of Kasek stand back on November the twenty seventh 179 00:11:48.440 --> 00:11:51.240 and involved obening the Earth some three thousand, eight hundred 180 00:11:51.279 --> 00:11:54.000 and fifty six times, traveling more than one hundred and 181 00:11:54.039 --> 00:11:58.080 sixty million kilometers. While on station, the crew were involved 182 00:11:58.080 --> 00:12:01.360 in more than two hundred and fifty scientific experiments, including 183 00:12:01.440 --> 00:12:04.919 research on new cancer treatments and improving in space manufacturing 184 00:12:04.960 --> 00:12:08.840 of materials used in high performance computers and electronics. They 185 00:12:08.879 --> 00:12:12.799 also undertook two extra vehicular activities or EVAs NASA speKt 186 00:12:12.799 --> 00:12:16.240 for spacewalks. These were designed to prepare for station power 187 00:12:16.279 --> 00:12:18.960 system upgrades and to replace a faulty joint in the 188 00:12:19.000 --> 00:12:23.320 Canada ARM two robotic arm. For more than twenty five 189 00:12:23.440 --> 00:12:26.559 years now, people have lived and worked continuously in space 190 00:12:26.639 --> 00:12:30.000 aboard the International Space Station. The Orbiting our Post is 191 00:12:30.039 --> 00:12:33.720 helping NASA understand and overcome the challenges of human spaceflight 192 00:12:33.799 --> 00:12:36.879 for long duration missions to the Moon and eventually onto 193 00:12:36.919 --> 00:12:40.399 Mars and beyond. As part of the Artemis program, However, 194 00:12:40.480 --> 00:12:43.720 the space station's future is now limited, with NASA planning 195 00:12:43.759 --> 00:12:46.000 to deorbit one hundred and nine meter long four hundred 196 00:12:46.000 --> 00:12:48.759 and twenty one our posts sometime in late twenty thirty 197 00:12:48.840 --> 00:12:52.399 or early twenty thirty one. It'll be replaced by smaller 198 00:12:52.399 --> 00:12:56.519 commercial space stations and a major expansion of China's Tiangong 199 00:12:56.600 --> 00:13:01.000 space station, which will double its size this space time 200 00:13:16.799 --> 00:13:19.240 and Time Out of turn oives to the skies and 201 00:13:19.360 --> 00:13:23.440 check out the celestiousphere for August on SkyWatch. August is 202 00:13:23.480 --> 00:13:26.679 the eighth month of the year in the Julian Engagorian calendars. 203 00:13:27.279 --> 00:13:30.039 It was originally named six Tillius in Latin because it 204 00:13:30.080 --> 00:13:32.519 was the sixth month of the original ten month Roman 205 00:13:32.519 --> 00:13:35.879 calendar under Romulus in seven fifty three BCE, when the 206 00:13:35.960 --> 00:13:39.360 year started in March. It only became the eighth month 207 00:13:39.399 --> 00:13:41.840 when January and February were added to the start of 208 00:13:41.879 --> 00:13:45.080 the year in the year eight BCE. It was renamed 209 00:13:45.080 --> 00:13:48.080 in honor of the Roman statesmen and military leader Augustus, 210 00:13:48.159 --> 00:13:52.080 who had achieved several military victories, including the conquest of Egypt. 211 00:13:52.200 --> 00:13:55.720 During the month. Okay, turning to the heavens and the 212 00:13:55.799 --> 00:13:59.919 constellation s, the Scorpion is high overhead this time of year, 213 00:14:00.120 --> 00:14:03.799 covering almost a third of the August night skies. At 214 00:14:03.840 --> 00:14:06.559 the heart of Scorpius, located some four hundred and seventy 215 00:14:06.639 --> 00:14:10.919 light years away, is the red super giant Antaries. A 216 00:14:11.000 --> 00:14:14.080 light year is a distance of about ten trillion kilometers, 217 00:14:14.279 --> 00:14:16.320 a distance of photon can travel in a year at 218 00:14:16.320 --> 00:14:19.200 three hundred thousand kilometres per second, the speed of light 219 00:14:19.240 --> 00:14:22.120 in a vacuum and the ultimate speed limit of the universe. 220 00:14:22.960 --> 00:14:26.639 The name Antaries means rival of Mars, and indeed, when 221 00:14:26.639 --> 00:14:29.840 they're close together in the sky, they do look very similar. 222 00:14:30.440 --> 00:14:33.639 And Tari's, or Alpha Scorpius that's sometimes called has some 223 00:14:33.679 --> 00:14:36.720 twelve point four times the mass and an incredible four 224 00:14:36.799 --> 00:14:39.519 hundred and fifty times the diameter of our Sun and 225 00:14:39.720 --> 00:14:42.320 is one of the largest known stars in the universe. 226 00:14:43.000 --> 00:14:45.600 And Tari's is so big that wordplace where the Sun 227 00:14:45.679 --> 00:14:47.720 is at the center of our solar system, it would 228 00:14:47.759 --> 00:14:51.120 engulf all the inner planets Mercury, Venus, Earth, and Mars. 229 00:14:51.759 --> 00:14:54.679 It's outer surface would rich almost as far as the 230 00:14:54.759 --> 00:14:58.919 orbit of Jupiter. And Tari's is a binary system, there's 231 00:14:58.960 --> 00:15:02.399 a companion style orbiting with it called Antari's B, a 232 00:15:02.519 --> 00:15:05.559 massive spectual type B blue white star at least seven 233 00:15:05.559 --> 00:15:07.960 point two times the mass and five point two times 234 00:15:07.960 --> 00:15:11.159 the radius of the Sun. It's located about two hundred 235 00:15:11.200 --> 00:15:14.759 and twenty four astronomical units beyond the primary star. An 236 00:15:14.799 --> 00:15:17.919 astronomical unit is the average distance between the Sun and 237 00:15:17.960 --> 00:15:20.919 the Earth, about one hundred and fifty million kilometers or 238 00:15:21.000 --> 00:15:26.000 eight point three light minutes. Astronomers describe stars in terms 239 00:15:26.080 --> 00:15:30.720 of spectual types, a classification system based on temperature and characteristics. 240 00:15:31.320 --> 00:15:34.519 The hottest, most massive, and most luminous stars are known 241 00:15:34.759 --> 00:15:39.000 spectro type O blue stars. They're closely followed by spectual 242 00:15:39.039 --> 00:15:42.039 type B blue white stars, the n spectual type A 243 00:15:42.200 --> 00:15:46.840 white stars, spetual type F whitish yellow stars, spectro type 244 00:15:46.879 --> 00:15:49.960 G yellow stars. That's where our Sun fits in, special 245 00:15:50.039 --> 00:15:53.440 type K orange stars, and the coolest and least massive 246 00:15:53.519 --> 00:15:57.679 of all stars are spectual type M red stars, commonly 247 00:15:57.720 --> 00:16:01.840 referred to as red dwarfs. Each spectral classification is further 248 00:16:01.879 --> 00:16:05.759 subdivided using a numeric digit to represent temperature, with zero 249 00:16:05.919 --> 00:16:09.080 being the hottest and nine the coolest, and a Roman 250 00:16:09.159 --> 00:16:12.919 uneral to represent luminosity. Now put all that together, and 251 00:16:12.960 --> 00:16:16.159 our sun is a special type G two V or 252 00:16:16.240 --> 00:16:20.279 G two five yellow dwarf star. Also included in the 253 00:16:20.279 --> 00:16:24.879 stellar classification system are special types LT and Y, which 254 00:16:24.919 --> 00:16:28.440 are assigned to feldstars known as brown dwarves, some of 255 00:16:28.480 --> 00:16:31.759 which were actually born as spectral type M red dwarf stars, 256 00:16:31.840 --> 00:16:35.000 but became brown dwarves after losing some of their mass. 257 00:16:35.519 --> 00:16:38.720 Brown dwarfs fitted to a category between the largest planets, 258 00:16:38.720 --> 00:16:41.279 which are about thirteen times the mass of Jupiter, and 259 00:16:41.360 --> 00:16:44.559 the smallest spectral type M red dwarf stars, which are 260 00:16:44.600 --> 00:16:47.200 about seventy five to eighty times the mass of Jupiter 261 00:16:47.480 --> 00:16:52.440 or zero point zero eight solar masses. Located near antaries 262 00:16:52.759 --> 00:16:56.519 is the spectacular globular cluster Messi four or M four 263 00:16:56.679 --> 00:17:00.360 for short, named after the eighteenth century of frenchist ronomoer 264 00:17:00.360 --> 00:17:03.320 and commet hunter Charles Messier, It's one of a catalog 265 00:17:03.360 --> 00:17:06.319 of one hundred and three fuzzy objects which weren't comets 266 00:17:06.599 --> 00:17:09.119 and so were of no interest to Messier, and so 267 00:17:09.200 --> 00:17:11.119 he made a list of them so he didn't waste 268 00:17:11.119 --> 00:17:14.319 his time looking at them. Other astronomers have since added 269 00:17:14.359 --> 00:17:17.440 further celestial objects to the catalog, bringing the turtle to 270 00:17:17.519 --> 00:17:20.920 around one hundred and ten. Located some seven thousand light 271 00:17:21.000 --> 00:17:23.319 years away, messi at four can be seen through a 272 00:17:23.359 --> 00:17:26.119 pair of binoculars, making it one of the closest globular 273 00:17:26.119 --> 00:17:30.400 clusters to Earth. Globular clusters are densely packed fees containing 274 00:17:30.519 --> 00:17:34.480 thousands to millions of gravitationally bounced stars, which it's thought 275 00:17:34.519 --> 00:17:37.119 were either originally all born at the same time in 276 00:17:37.160 --> 00:17:40.440 the same stellar nursery, or of the surviving cause of 277 00:17:40.519 --> 00:17:44.880 galaxies that have been cannibalized by larger galaxies. They're almost 278 00:17:44.920 --> 00:17:48.759 always found orbiting the halo of galaxies. The Milky Way 279 00:17:48.799 --> 00:17:50.759 has about one hundred and fifty of them, and they're 280 00:17:50.799 --> 00:17:54.079 all usually very ancient, some dating back to around twelve 281 00:17:54.200 --> 00:17:58.440 billion years. Located just below the sting of Scorpius are 282 00:17:58.480 --> 00:18:02.319 two open star clusters M six and M seven. M 283 00:18:02.400 --> 00:18:05.119 sevens the nearer of the two, located about eight hundred 284 00:18:05.200 --> 00:18:07.839 light years away, while M six is a more distant 285 00:18:07.880 --> 00:18:11.799 two thousand light years. Open clusters are less densely packed 286 00:18:11.799 --> 00:18:15.160 than their globular cluster counterparts, with the stars inside them 287 00:18:15.200 --> 00:18:19.200 less gravitationally bound and more prone to drifting away over time. 288 00:18:19.880 --> 00:18:23.599 Another open star cluster in Scorpius is NNGC sixty two 289 00:18:23.640 --> 00:18:27.240 to thirty one, located about six five hundred light years away, 290 00:18:27.480 --> 00:18:31.640 just near the stars Zeta Scorpii. NGC sixty two thirty 291 00:18:31.640 --> 00:18:34.319 one is a bright, open star cluster containing around one 292 00:18:34.400 --> 00:18:38.039 hundred and twenty stars, including a significant population of highly 293 00:18:38.119 --> 00:18:42.440 luminous supergiants, numerous white yellow stars, and at least two 294 00:18:42.599 --> 00:18:48.079 Wolfrayet stars. Wolfrayets are extremely luminous evolved stars reaching the 295 00:18:48.200 --> 00:18:51.480 ends of their lives. Having run out of hydrogen for 296 00:18:51.559 --> 00:18:54.480 core fusion. They're no longer on the main sequence and 297 00:18:54.519 --> 00:18:58.440 are instead fusing progressively heavier and heavier elements in their cores. 298 00:18:59.200 --> 00:19:01.640 This causes them to have surface temperatures of up to 299 00:19:01.680 --> 00:19:05.839 two hundred thousand degrees celsius, and such extreme temperatures generate 300 00:19:06.000 --> 00:19:11.799 powerful stellar winds. Just behind Scorpius is the constellation Sagittarius, 301 00:19:12.039 --> 00:19:15.640 the half man, half horse of Greek mythology, and as 302 00:19:15.680 --> 00:19:18.160 we mentioned in last month SkyWatch, the center of the 303 00:19:18.200 --> 00:19:21.880 Milky Way galaxy is found in Sagittarius, roughly twenty seven 304 00:19:21.920 --> 00:19:25.440 thousand light years away. The name Sagittarius could be traced 305 00:19:25.440 --> 00:19:29.279 back beyond the Greeks to the ancient Mesopotamian archer god Nergel. 306 00:19:29.880 --> 00:19:33.000 Sagittarius is known for its many nebula and clusters, more 307 00:19:33.039 --> 00:19:36.480 than any other constellation. One of the largest and brightest 308 00:19:36.759 --> 00:19:39.640 is the globular cluster M twenty two, big enough to 309 00:19:39.640 --> 00:19:43.279 be visible to the unaided eye, located about ten thousand, 310 00:19:43.359 --> 00:19:46.240 six hundred light years away near the galactic bulge. M 311 00:19:46.319 --> 00:19:50.000 twenty two is more elliptical the most globular clusters. It's 312 00:19:50.079 --> 00:19:53.039 located just south of the ecliptic that're played in the 313 00:19:53.079 --> 00:19:56.160 sky upon which all the planets orbit the Sun, and 314 00:19:56.240 --> 00:20:00.119 it contains over seventy thousand stars covering an area of 315 00:20:00.160 --> 00:20:03.480 around one hundred light years. It also contains at least 316 00:20:03.480 --> 00:20:06.079 two black holes, and he's one of only a handful 317 00:20:06.119 --> 00:20:10.079 of globular clusters known to contain planetary nebulae, the puffed 318 00:20:10.119 --> 00:20:15.000 off outer gases envelopes of dead sun like stars. Located 319 00:20:15.000 --> 00:20:17.960 in the sky next to Scorpius in the western Sagittarius 320 00:20:17.960 --> 00:20:21.240 in the east is the constellation of Fayusius, the healer 321 00:20:21.359 --> 00:20:24.759 or serpent bearer, often betrayed as a snake coiled around 322 00:20:24.759 --> 00:20:28.839 a man in Greek mythology, Opaiucius raises a rind from 323 00:20:28.880 --> 00:20:32.240 the dead after he was bitten by Scorpius O Fa 324 00:20:32.279 --> 00:20:36.000 Yushius contains several star clusters and other interesting features, including 325 00:20:36.079 --> 00:20:40.079 Barnard Star. Barnard Star is the second nearest star system 326 00:20:40.160 --> 00:20:43.960 to the Sun, beaten only by the Alphasentaury Triple star system, 327 00:20:44.519 --> 00:20:47.880 located some five point nine light years away. Barnard Star 328 00:20:48.079 --> 00:20:51.240 is a spectral type M red dwarf, about zero point 329 00:20:51.279 --> 00:20:54.400 one four four times the mass of the Sun. Our 330 00:20:54.519 --> 00:20:58.000 Sun is around four point six billion years old. At 331 00:20:58.039 --> 00:21:01.000 between seven and twelve billion years of ever age, Barnard's 332 00:21:01.000 --> 00:21:03.880 Star is considerably older than the Sun and maybe among 333 00:21:03.920 --> 00:21:07.559 the oldest stars in the Milky Way galaxy. It's lost 334 00:21:07.599 --> 00:21:11.319 a great deal of rotational energy, and its periodic slight 335 00:21:11.440 --> 00:21:14.920 changes in brightness indicate that it's rotating about once every 336 00:21:14.920 --> 00:21:19.119 one hundred and thirty days. By comparison, our Sun rotates 337 00:21:19.200 --> 00:21:23.119 roughly once every twenty nine days. Given its age, Bernard 338 00:21:23.160 --> 00:21:25.680 Star was long assumed to be quiercent in terms of 339 00:21:25.680 --> 00:21:29.680 stellar activity, but in nineteen ninety eight astronoms observed an 340 00:21:29.720 --> 00:21:33.799 intense stellar flare, indicating that Barnard Star is indeed a flare. 341 00:21:33.880 --> 00:21:38.480 Star flare stars of variable stars they can undergo unpredictable 342 00:21:38.559 --> 00:21:42.799 dramatic increases in brightness, lasting a few minutes. It's believed 343 00:21:42.799 --> 00:21:45.680 that the flares of flare stars are analogous to solar 344 00:21:45.720 --> 00:21:48.519 flares in the Sun, and that they're generated by stellar 345 00:21:48.559 --> 00:21:53.119 magnetic energy stored in the star's atmosphere. Lying just to 346 00:21:53.160 --> 00:21:55.960 the west of the scorpion is the constellation Libra at 347 00:21:55.960 --> 00:22:00.240 the scales. In Greek mythology, Libra represents the core of 348 00:22:00.279 --> 00:22:04.279 Scorpius the scorpion. However, the Romans considered Libra a distinct, 349 00:22:04.319 --> 00:22:07.599 separate constellation from Scorpius, and thought them to be the 350 00:22:07.640 --> 00:22:10.960 scales symbolizing the equinoxes, the times of the year in 351 00:22:11.039 --> 00:22:13.839 March and September, when the Earth gets equal lengths of 352 00:22:13.920 --> 00:22:17.039 day and night. That's because two thousand years ago, when 353 00:22:17.079 --> 00:22:19.519 all this was made up, the Sun moved into Libre 354 00:22:19.640 --> 00:22:23.000 at the time of the September equinox, but due to procession, 355 00:22:23.079 --> 00:22:26.000 as the Earth Spentax's wobbles in direction, this point in 356 00:22:26.079 --> 00:22:30.279 time has now moved into the adjoining constellation of Virgo. 357 00:22:30.440 --> 00:22:32.559 If you look to the south and the southern cross, 358 00:22:32.640 --> 00:22:37.039 that's the constellation Centaurus. Another half man, half horse mythical 359 00:22:37.079 --> 00:22:40.640 beast Centaurus was the teacher of many of the Greek 360 00:22:40.640 --> 00:22:43.759 gods and heroes. He was placed among the stars in 361 00:22:43.799 --> 00:22:47.039 the heavens after accidentally being kured by a poisoned arrow 362 00:22:47.079 --> 00:22:51.000 fired by Hercules close to the point of star nearest 363 00:22:51.039 --> 00:22:55.519 the southern cross. Beta Centauri lies NNGC fifty one thirty nine. 364 00:22:55.680 --> 00:22:59.640 Omega Centauri the largest and brightest globular cluster in the 365 00:22:59.720 --> 00:23:04.160 visible sky. Because of its brightness, the ancient Greek mathematician 366 00:23:04.200 --> 00:23:08.480 and astronomer Claudius Ptolemy originally thought Amiga Centauri was a star. 367 00:23:09.319 --> 00:23:11.319 It has a diameter of more than one hundred and 368 00:23:11.359 --> 00:23:15.640 fifty light years and contains an estimated ten million stars, 369 00:23:16.000 --> 00:23:18.839 giving it some four million times the mass of our Sun. 370 00:23:19.519 --> 00:23:23.079 Located some fifteen thy eight hundred light years away, Amiga 371 00:23:23.119 --> 00:23:27.119 Centauri is another very ancient globular cluster, around twelve billion 372 00:23:27.200 --> 00:23:31.599 years old, and it contains many so called population two stars. 373 00:23:32.240 --> 00:23:35.319 These are the second generation of stars to have formed, 374 00:23:35.839 --> 00:23:38.279 and were created directly out of the remains of the 375 00:23:38.400 --> 00:23:41.839 very first stars in the universe. Stars in the core 376 00:23:41.880 --> 00:23:45.160 of Amiga Centauri are so crowded yarreestimated to average only 377 00:23:45.279 --> 00:23:48.119 zero point one light years away from each other, and 378 00:23:48.200 --> 00:23:51.519 that compares to the nearest start of our sun proximate century, 379 00:23:51.640 --> 00:23:55.599 which is some four point two light years distant. Located 380 00:23:55.680 --> 00:23:59.440 close to a megasentaurium the sky is the giant lenticular 381 00:23:59.480 --> 00:24:04.039 galaxy NNGC fifty one twenty eight Centaurus A, which we 382 00:24:04.119 --> 00:24:06.359 see looking like it's split in half by a thick 383 00:24:06.400 --> 00:24:09.839 band of dust. The galaxy was discovered in eighteen twenty 384 00:24:09.920 --> 00:24:13.279 six by astronomer James Dunlop from his home in what 385 00:24:13.440 --> 00:24:16.759 is now the Sydney suburb of Paramatta, a time long 386 00:24:16.799 --> 00:24:19.240 before the bright lights of a modern city would make 387 00:24:19.319 --> 00:24:23.799 such a discovery impossible. Located some thirteen million light years away, 388 00:24:24.079 --> 00:24:27.039 Centaurus is one of the strongest radio sources in the 389 00:24:27.079 --> 00:24:29.799 sky and is thought to be the result of a 390 00:24:29.880 --> 00:24:33.640 merger between an elliptical and a spiral galaxy. It can 391 00:24:33.720 --> 00:24:36.640 easily seen using a pair of binoculars, but you'll need 392 00:24:36.680 --> 00:24:41.160 a telescope to make out its spectacular dust lanes. August 393 00:24:41.240 --> 00:24:43.400 is also the time of the peak of the annual 394 00:24:43.440 --> 00:24:47.880 Percied's meteor shower. The meteors are the debris trail ejected 395 00:24:47.920 --> 00:24:50.720 by the comets with tuttle as it travels along its 396 00:24:50.759 --> 00:24:54.160 one hundred and thirty three year orbit through the Solar System. 397 00:24:54.319 --> 00:24:57.240 As its name suggests, the perseed's radiant that is the 398 00:24:57.279 --> 00:24:59.960 point of the sky from which the meteors appear to originate. 399 00:25:00.000 --> 00:25:03.839 It lies in the constellation of Perseus. The Perseids one 400 00:25:03.839 --> 00:25:07.680 of the oldest known meteor showers, with early Chinese historical 401 00:25:07.720 --> 00:25:10.839