Draco (el dragón) es una constelación del norte lejano, que es circumpolar para muchos observadores del hemisferio norte. Es una de las 88 constelaciones modernas, y una de las 48 constelaciones listadas por Ptolomeo. El polo norte de la eclíptica está en Draco.
Aunque muy grande, Draco no tiene estrellas especialmente brillantes. La cabeza del dragón está representada por un cuadrilátero de estrellas situadas entre Hércules y la Osa Menor.
La segunda estrella más brillante de Draco es Athebyne4 o Aldhibain (η Draconis), una gigante amarilla de tipo G8IIIb con una luminosidad 60 veces superior a la del Sol.5Muy parecida a ella es también δ Draconis, denominada Altais.4 Ambas estrellas están a poco menos de 100 años luz de la Tierra.
β Draconis, oficialmente llamada Rastaban,4 tercera estrella en cuanto a brillo, es una supergigante o gigante luminosa amarilla que se encuentra a 380 años luz de distancia. Su radio es 40 veces más grande que el del Sol6 y su masa 6 veces mayor que la de nuestra estrella.7 Tiene una tenue compañera estelar a una distancia de al menos 450 ua.8ε Draconis es otra gigante amarilla de tipo G7IIIb y 2,7 masas solares9 que se encuentra a 153 años luz.
En contraste, Edasich (ι Draconis)4 es una gigante naranja de tipo K2III cuya metalicidad es superior a la solar ([Fe/H] = +0,16). Su radio es 11,9 veces más grande que el radio solar.12 Alrededor de esta estrella orbita Hypatia,1314 planeta de tipo «superjúpiter» con una temperatura de 598 K. La acusada excentricidad de su órbita hace que la separación entre estrella y planeta fluctúe entre 0,39 y 2,1 ua.15
χ Draconis es un sistema binario cercano, pues se encuentra a solo 26 años luz. Está integrado por una estrella blanco-amarilla de tipo F7V casi dos veces más luminosa que el Sol y una enana naranja de tipo K0V.16 La separación entre ambas componentes varía entre 0,6 y 1,4 ua a lo largo de una órbita excéntrica que completan cada 280,55 días. De características muy distintas, λ Draconis —llamada Gianfar o Giausar, su nombre oficial—, es una fría gigante roja de tipo M0III,17 3958 K de temperatura6 y cuyo tamaño es 70 veces más grande que el del Sol.12
Entre las variables de Draco está Z Draconis, una binaria eclipsante cuyo brillo disminuye 3,30 magnitudes durante el eclipse principal y 0,20 magnitudes durante el eclipse secundario; la componente principal es de tipo A5V y tiene 1,6 masas solares.20 Su período orbital es de 1,3575 días y tiende a aumentar con el tiempo.21 Por su parte, RY Draconis es una de las estrellas de carbono más próximas a la Tierra —está a unos 1200 años luz de distancia— y una de las más brillantes en banda J, región del infrarrojo cercano centrada en 1,25 μm.22También en esta constelación se localiza BY Draconis, prototipo de una clase de variables que llevan su nombre (variables BY Draconis). Las variaciones de luminosidad en estas estrellas están asociadas a la rotación estelar, debido a la presencia de manchas en su superficie u otro tipo de actividad cromosférica. Otra variable, AG Draconis, es una de las estrellas simbióticas más estudiadas. Es una binaria formada por una gigante naranja y una enana blanca envuelta en una nebulosidad.23 El sistema sufre estallidos —que llegan a quintuplicar su brillo—24 cuando se produce transferencia de masa desde la atmósfera de la gigante al entorno de la enana blanca.
En Draco se localiza HD 101364, estrella casi idéntica al Sol. Sus características físicas así como su composición química, prácticamente iguales a las del Sol, la convierten probablemente en el gemelo solar más cercano a nuestra estrella.25 A diferencia de otros gemelos solares, el contenido en litio de HD 101364 (A(Li) = 1,22)26 es muy próximo al solar, pues el Sol parece estar empobrecido en litio en un factor de 10 frente a otras estrellas de disco semejantes.27
Entre las estrellas con sistemas planetarios se encuentra HD 158259, enana amarilla con cinco exoplanetas confirmados, siendo el más interior —separado solo 0,034 ua de la estrella— un planeta de tipo «supertierra».28Asimismo, Kepler-90 es una distante estrella de tipo espectral F929 con un sistema planetario de ocho exoplanetas, siendo semejante al sistema solar en cuanto a que los planetas rocosos están más cerca de la estrella y los gigantes gaseosos más alejados.30Kepler-1 es otra estrella lejana donde se ha detectado un planeta de tipo «júpiter caliente» cuyo albedo geométrico extremadamente bajo le convierte en el exoplaneta más oscuro conocido.31Por su parte, HD 167042 es una estrella de tipo K1 en torno a la cual orbita un planeta gigante que completa su órbita en 412,6 días.32
La estrella de Draco más cercana a la Tierra es el sistema estelar Struve 2398, situado a 11,52 años luz de distancia. Las componentes del sistema son dos enanas rojas de tipo M3V y M3.5V3334 bastante similares. Los parámetros orbitales del sistema no son bien conocidos: se ha evaluado su período orbital en 453 años y, dada la gran excentricidad de la órbita (ε = 0,53), la distancia entre las dos estrellas varía entre 26 y 85 ua.35
Uno de los objetos del cielo profundo más conocidos en Draco es la nebulosa Ojo de Gato (NGC 6543), nebulosa planetaria que está a 5300 años luz de distancia.36 Muestra una compleja morfología bipolar con dos estructuras visibles, una interior elipsoidal y otra externa bipolar cons dos lóbulos casi esféricos; también se pueden observar dos chorros o «jets» alrededor de la nebulosa. Los estudios espectroscópicos no están de acuerdo sobre si la estrella central es una binaria cercana o simplemente una única estrella variable, aunque modelos morfocinemáticos sugieren la primera opción.37
Entre las galaxias observables en la constelación se encuentra NGC 5866 (también llamada galaxia Eje o Messier 102), una galaxia lenticular o espiral distante 50 millones de años luz38 que probablemente fue descubierta por Pierre Méchain o Charles Messier en 1781. La medida de las velocidades orbitales de sus cúmulos globulares39 implica que su materia oscura supone solo el 34 - 45 % de la masa total de la galaxia, cifra notablemente baja. Da nombre al Grupo de NGC 5866 —del que forma parte— y que tiene como otros miembros a NGC 5879 y NGC 5907. Por otro lado, Arp 188 es una galaxia espiral barrada situada a 420 millones de años luz de distancia. Su característica más notable es un rastro de estrellas de unos 280 000 años luz de largo originada por la colisión con una pequeña galaxia compacta.40
NGC 6503 es una galaxia espiral enana situada en el borde de la región del espacio conocida como el Vacío Local. Se encuentra a unos 18 millones de años luz de distancia
Different cyclotron size: a) Lawrence ́s first one, b) Venezuela First one (courtesy of Dorly Coehlo), c) Fermi National Laboratory at CERN. And size matters, and Cyclotrons win as best hospital candidates due to Reactors are bigger, harder and difficult to be set in a hospital installation. Can you imagine a nuclear reactor inside a health installation? Radiation Protection Program will consume all the budget available. Size, controlled reactions, electrical control, made cyclotrons easy to install, and baby cyclotrons come selfshielded so hospital don ́t need to spend money in a extremely large bunker. Now on, we are going to talk about our first experience with the set up of a baby cyclotron for medical uses inside the first PET installation in Latin America. “Baby” means its acceleration “D” diameters are suitable to be set inside a standard hospital room dimensions, with all its needs to be safetly shielded for production transmision and synthetized for human uses for imaging in Nuclear Medicine PET routine. When we ask why Cyclotrons are better than reactors for radioisotopes production to be used in Medicine, we also have to have in mind that they has: 1. Less radioactive waste 2. Less harmful debris
Different cyclotron size: a) Lawrence ́s first one, b) Venezuela First one (courtesy of Dorly Coehlo), c) Fermi National Laboratory at CERN. And size matters, and Cyclotrons win as best hospital candidates due to Reactors are bigger, harder and difficult to be set in a hospital installation. Can you imagine a nuclear reactor inside a health installation? Radiation Protection Program will consume all the budget available. Size, controlled reactions, electrical control, made cyclotrons easy to install, and baby cyclotrons come selfshielded so hospital don ́t need to spend money in a extremely large bunker. Now on, we are going to talk about our first experience with the set up of a baby cyclotron for medical uses inside the first PET installation in Latin America. “Baby” means its acceleration “D” diameters are suitable to be set inside a standard hospital room dimensions, with all its needs to be safetly shielded for production transmision and synthetized for human uses for imaging in Nuclear Medicine PET routine. When we ask why Cyclotrons are better than reactors for radioisotopes production to be used in Medicine, we also have to have in mind that they has: 1. Less radioactive waste 2. Less harmful debris
The issue meant that the planned launch on Tuesday morning was pushed to Wednesday to allow for a thorough investigation of the issue and to implement additional safety checks.
In an announcement, SpaceX stated: "Teams are taking a closer look at a ground-side helium leak on the Quick Disconnect umbilical.
"Falcon and Dragon remain healthy and the crew continues to be ready for their multi-day mission to low-Earth orbit. Next launch opportunity is no earlier than Wednesday, 28 August."
Spacex's CEO and renowned entrepreneur Elon Musk posted on social media regarding the groundbreaking journey, reports the Express US. He said: "An incredible amount of work has gone into this historic mission by an amazing team. We are triple-checking everything to make sure there is nothing more we can do to improve crew safety."
The flight will launch on a Falcon 9 rocket(
Image:
(Image: Getty))
Furthermore, he highlighted the significance of the mission, tweeting: "Crew safety is absolutely paramount and this mission carries more risk than usual, as it will be the furthest humans have traveled from Earth since Apollo and the first commercial spacewalk! ".
Reaffirming their commitment to the schedule, SpaceX aims to maintain the initial early morning launch timing of 3:38 am ET on Wednesday at the storied Launch Complex 39A of NASA's Kennedy Space Center in Florida. More options are also on the table with additional lift-off times of 5:23 am ET and 7:09 am ET.
If the preferred launch windows aren't workable, they've got a fallback on Thursday, August 29. Just three days into the space mission, an EVA is scheduled to test out SpaceX's cutting-edge spacesuits.
Designed for deep space escapades and to shield against intense cosmic radiation in the Van Allen belts, these EVA suits are at the forefront of aerospace innovation alongside the Polaris Dawn spacecraft.
Tech mogul Jared Isaacman, a pioneer in private space travel, is commandeering and bankrolling this five-day cosmic voyage. No stranger to the stars after his self-financed 2021 flight on a Crew Dragon craft, Isaacman is the seasoned spacefarer of the group.
Despite recent delays, Isaacman shared from isolation that the team is geared up and waiting for liftoff as soon as the glitch is sorted out.
He stated on X: "The best aerospace engineers in the world are working on the issue, and we promise to put on a great show soon enough. When the call comes, we won't hesitate to strap in."
The great circle alignment from Giza to Alexandria has an azimuth of 51.85° north of due west from Giza (the same angle as the slope of the Great Pyramid). Extended beyond Alexandria, this great circle also crosses over Delphi, Rollright and Newgrange, as well as the city of London.
Dendera was dedicated to Isis/Sirius. The ancient Egyptian year began on the date of the heliacal rising of Sirius in mid July. The helical rising of Sirius heralded the annual inundation of the Nile that was essential to the welfare of ancient Egypt. The axis of the temple of Isis at Dendera was aligned 20° south of due east, pointing directly at the rising point of Sirius from the latitude of Dendera.
Robert Bauval describes a number of connections between Isis/Sirius and Paris in Talisman (2004). Isis is shown riding on a boat in many ancient Egyptian drawings and carvings. At the direction of Napoleon, Sirius and a statue of Isis were added to the coat of arms for Paris shown below.
During the French revolution, a statue of Isis known as the Fountain of Regeneration was constructed on the former site of the Bastille. The engraving below commemorated this statue.
The Elysian Fields is described as a place of eternal salvation in the ancient Egyptian Book of the Dead. Named after the Elysian Fields, the Champs Elysees is the main axis of Paris. The names Elysian and Elysees both suggest an association with Isis. The photograph below is facing southeast. The Arc de Triumphe is visible in the background. Beyond the Arc de Triumphe is the Louvre. The azimuth of the Champs Elysees is 26° south of due east, pointing directly at the rising point of Sirius/Isis from the latitude of Paris.
The termination point of the Champs Elysees to the northwest is the Grande Arche, in the foreground of the picture above. The axis of the Grande Arche is offset 6.33° south of the axis of the Champs Elysees. With an azimuth of just over 32° south of due east, the azimuth of the axis of the Grande Arche is the same as the azimuth of the great circle alignment from Paris to Dendera.
The Grande Arche is a nearly perfect cube with a height of 110 meters, a width of 108 meters and a depth of 112 meters. It is often described as a cube with side lengths of 110 meters. This is equal to 210 ancient Egyptian cubits:
110/210 = .5238
.5238 meters is a precise measure of the ancient Egyptian cubit, equating to 20.6222 inches, well within the ± .005 inches in Petrie's 20.62 inch measure of the ancient Egyptian cubit. Instead of the usual comparisons between the cubit and the meter of .52375/1 or .524/1, the best comparative measure may be the simple fraction of 11/21 that is suggested by the Grande Arche.
The sides of the Grande Arche are divided into 5 x 5 large panels and within each large panel are 7 x 7 smaller panels. Side lengths of 110 meters suggest lengths of 22 meters for the sides of the large panels with lengths of 22/7 meters for the sides of the smaller panels. The fraction 22/7 equals 3.1428, an accurate expression of π that is also found in the dimensions of the Great Pyramid. Side lengths of 210 cubits in the Grande Arche suggest lengths of 42 cubits for the sides of the large panels and 6 cubits for the sides of the smaller panels. This also shows that the relationship between the meter and the cubit is 6/π, using the measure of 22/7 for π:
21/11 = 6/π
22/7 x 21/11 = 6
The northern pyramid at Dashur, known as the Red Pyramid, was the first true (smooth sided) pyramid built in Egypt and it was the last pyramid built prior to construction of the Great Pyramid. The baselengths of the Red Pyramid are 420 cubits (220 meters) long, 20x multiples of 21/11.
One of the oldest stone circles in England is at Rollright. The diameter of the Rollright circle is 31.4 meters, an accurate expression of π times 10 meters. Given the 6/π relationship between the meter and the cubit, the diameter of the Rollright circle is also 60 ancient Egyptian cubits.
Biden lands in France for D-Day anniversary, democracy speech
PARIS, June 4 (Reuters) - President Joe Biden landed in France on Wednesday to commemorate the 80th anniversary of D-Day on a trip designed to underscore his commitment to U.S. allies in Europe and contrast his vision of democracy with his 2024 political opponent Donald Trump.
Biden will spend five days in France and attend D-Day celebrations in Normandy, where U.S. and allied forces stormed French beaches in an attack that helped defeat Nazi Germany in World War II, as well as deliver a high-profile speech and hold a formal state visit with President Emmanuel Macron.
While in Normandy Biden will sit down for talks with Ukraine President Volodymyr Zelenskiy about the war effort to repel Russian invaders, White House national security adviser Jake Sullivan told reporters aboard the presidential flight to Paris.
Biden's remarks in Normandy, both on Thursday at the formal 80th anniversary ceremony and on Friday at the famed Pointe du Hoc cliffs, will center around the dangers of isolationism and the need to stand up to dictators, Sullivan said.
Biden will draw a connection from World War Two through the Cold War and creation of the NATO alliance to today, "where we face once again war in Europe, where NATO has rallied to defend freedom and sovereignty."
In what promises to be an emotional moment, Biden will meet the aged veterans who participated in the D-Day invasion.
White House national security spokesperson John Kirby said the potential use of some $300 billion in frozen Russian assets to aid Ukraine would be discussed by Biden and Macron during the visit.
Item 1 of 7 U.S. President Joe Biden is greeted by honor guard as he arrives at Paris-Orly Airport, France June 5, 2024. REUTERS/Elizabeth Frantz
[1/7]U.S. President Joe Biden is greeted by honor guard as he arrives at Paris-Orly Airport, France June 5, 2024. REUTERS/Elizabeth Frantz Purchase Licensing Rights, opens new tab
Biden, a Democrat, is running for re-election in November against Trump, a Republican, and has made preserving and strengthening U.S. democracy a key part of his campaign in the aftermath of Trump's chaotic four years in office.
Trump refused to accept the results of the 2020 election, which sparked a deadly attack on the U.S. Capitol by his supporters on January 6, 2021; he has vowed to go after political opponents, deport immigrants and punish whistleblowers in a second term.
Trump has threatened to abandon NATO allies if they do not bolster their defense spending and some fear he would pull the United States out of the alliance altogether if he were elected president again.
Biden's message on democracy could be complicated by his staunch backing of Israeli Prime Minister Netanyahu in Israel's war with Hamas in Gaza, which has killed tens of thousands of Palestinians, after Hamas attacked Israel in October last year, killing over one thousand.
The International Criminal Court has charged Netanyahu with war crimes and some international allies and left-leaning voters in the United States want Biden to stop the flow of U.S. military aid to Israel. The issue could hurt Biden in key states, including Michigan, in the November election.
The D-Day commemorations are set against a backdrop of a modern conflict in Europe, Russia's more than 2-year war with Ukraine.
At a political fundraiser before his trip, Biden called the D-Day invasion "one of the most important moments in the history of defense of freedom and democracy in the history of the world" and said the sacrifices from that day must not be given up.
"Democracy is literally on the ballot this year. The future of democracy and freedom is at stake. We have brave soldiers who gave their lives on the beaches of Normandy who did their part," he told donors in Connecticut on Monday.
Get weekly news and analysis on U.S. politics and how it matters to the world with the Reuters Politics U.S. newsletter. Sign up here.
Reporting by Jeff Mason and Paris newsroom; additional reporting by Steve Holland, Eric Beech, Kanishka Singh, Katharine Jackson and Andrea Shalal; Editing by Heather Timmons, Stephen Coates and Michael Perry
الفقرة السابقة
The flight will launch on a Falcon 9 rocket (
