Ciência e Tecnologia - Morte por 'esparguetificação'. Como um buraco negro engoliu uma estrela - Video

 ‘Esparguetificação’ quer dizer exatamente aquilo que parece. Imagine um fio de esparguete nos lábios e sugue-o até ele desaparecer dentro da boca. Basicamente foi isto que o buraco negro fez à estrela e os telescópicos do Observatório Astronómico do Sul (ESO), o Very Large Telescope (VLT) e o New Technology Telescope (NTT), estavam de lentes postas na situação.

Quando uma estrela infeliz se aproxima demasiado de um buraco negro supermassivo situado no centro de uma galáxia, a extrema atração gravitacional exercida pelo buraco negro desfaz a estrela em finas correntes de matéria,” explica Thomas Wevers, autor do estudo e bolseiro do ESO em Santiago do Chile, em comunicado de imprensa.

A estrela AT2019qiz, estava localizada num galáxia em espiral na constelação de Erídano, a cerca de 215 milhões de anos-luz da Terra. A estrela tinha uma massa equivalente à do nosso Sol, mas ficou reduzida a metade depois do encontro com o buraco negro que tinha mais de um milhão de vez a massa da estrela.

Observador - Portugal

Science & Technology - Astronomy picture of the day : Mars, Pleiades, and Andromeda over Stone Lions

 2020 October 13

Mars, Pleiades, and Andromeda over Stone Lions
Image Credit & Copyright: Cem Özkeser

Explanation: Three very different -- and very famous -- objects were all captured in a single frame last month. On the upper left is the bright blue Pleiades, perhaps the most famous cluster of stars on the night sky. The Pleiades (M45) is about 450 light years away and easily found a few degrees from Orion. On the upper right is the expansive Andromeda Galaxy, perhaps the most famous galaxy -- external to our own -- on the night sky. Andromeda (M31) is one of few objects visible to the unaided eye where you can see light that is millions of years old. In the middle is bright red Mars, perhaps the most famous planet on the night sky. Today Mars is at opposition, meaning that it is opposite the Sun, with the result that it is visible all night long. In the foreground is an ancient tomb in the Phygrian Valley in Turkey. The tomb, featuring two stone lions, is an impressive remnant of a powerful civilization that lived thousands of years ago. Mars, currently near its brightest, can be easily found toward the east just after sunset.

Science & Technology - Astronomy picture of the day : Descending Toward Asteroid Bennu

 2020 October 12

Descending Toward Asteroid Bennu
Video Credit: NASA, OSIRIS-REx, NASA's Scientific Visualization Studio; Data: NASA, U. Arizona, CSA, York U., MDA

Explanation: What would it be like to land on an asteroid? Although no human has yet done it, NASA's robotic OSIRIS-REx spacecraft is scheduled to attempt to touch the surface of asteroid 101955 Bennu next week. The goal is to collect a sample from the nearby minor planet for return to Earth for a detailed analysis in 2023. The featured video shows what it looks like to descend toward the 500-meter diamond-shaped asteroid, based on a digital map of Bennu's rocky surface constructed from image and surface data taken by OSIRIS-REx over the past 1.5 years. The video begins by showing a rapidly spinning Bennu -- much faster than its real rotation period of 4.3 hours. After the rotation stops, the virtual camera drops you down to just above the rugged surface and circles a house-sized rock outcrop named Simurgh, with the flatter outcrop Roc visible behind it. If the return sample reaches Earth successfully, it will be scrutinized for organic compounds that might have seeded a young Earth, rare or unusual elements and minerals, and clues about the early history of our Solar System.

Science & Technologie - Astronomy picture of the day : The Very Large Array at Moonset

 2020 10 octobre

The Very Large Array at Moonset
Image Credit: Jeff Hellermann, NRAO / AUI / NSF

Explication : Un spectacle inspirant, ces antennes géantes du Karl G. Jansky Very Large Array (VLA) s’élèvent au-dessus du désert du Nouveau-Mexique à moonset. Montées sur des piliers mais transportables sur les voies ferrées pour modifier la configuration du VLA, ses 27 antennes de fonctionnement sont chacune de la taille d’une maison (25 mètres de diamètre) et peuvent être organisées en un réseau couvrant la taille d’une ville (35 kilomètres). Un cheval de bataille prolifique de radioastronomie, le VLA a été utilisé pour découvrir l’eau sur la planète Mercure,coronae radio-brillante autour des étoiles, micro-quasars dans notre galaxie, gravitationnellement induit anneaux Einstein autour des galaxies lointaines, et les homologues radio à cosmologiquement lointains sursauts gamma. Sa grande taille a permis aux astronomes d’étudier les détails des galaxies radio, des jets cosmiques ultra-rapides, et de cartographier le centre de notre propre Voie lactée. Aujourd’hui, 40 ans après son dévouement, le VLA a été utilisé dans plus de 14 000 projets d’observation et a contribué à plus de 500 thèses de doctorat. Le 10 octobre, l’Observatoire national de radioastronomie organisera une journée de célébration en ligne de l’ALV à 40 ans avec des visites virtuelles et des présentations sur l’histoire, les opérations, la science et l’avenir du Very Large Array.

Science & Technologie - Astronomy picture of the day

2020 October 8

Mare Frigoris
Image Credit & Copyright: Matt Smith

Explanation: Lighter than typically dark, smooth, mare the Mare Frigoris lies in the far lunar north. Also known as the Sea of Cold, it stretches across the familiar lunar nearside in this close up of the waxing gibbous Moon's north polar region. Dark-floored, 95 kilometer wide crater Plato is just left of the center. Sunlit peaks of the lunar Alps (Montes Alpes) are highlighted below and right of Plato, between the more southern Mare Imbrium (Sea of Rains) and Mare Frigoris. The prominent straight feature cutting through the mountains is the lunar Alpine Valley (Vallis Alpes). Joining the Mare Imbrium and Mare Frigoris, the lunar valley is about 160 kilometers long and up to 10 kilometers wide.

Corn Moon Rising - (Science & Technology - Astronomy picture of the day)

2020 September 14
Corn Moon Rising 
Image Credit & Copyright: Zarcos Palma

Explanation: A rising moon can be a dramatic sight. A rising Full Corn Moon was captured early this month in time-lapse with a telephoto lens from nearly 30 kilometers away -- making Earth's ascending half-degree companion appear unusually impressive. The image was captured from Portugal, although much of the foreground -- including lights from the village of Puebla de Guzmán -- is in Spain. A Full Corn Moon is the name attributed to a full moon at this time of year by cultures of some northern indigenous peoples of the Americas, as it coincides with the ripening of corn. Note that the Moon does not appear larger when it is nearer the horizon -- its seemingly larger size there is only an illusion. The next full moon -- occurring at the beginning of next month -- will be known as the Full Harvest Moon as it occurs nearest in time to the northern autumnal equinox and the northern field harvests.

Une nouvelle imagerie du cerveau (Science & Technologie - Santé/Médecine)

Des chercheurs de l’Université de Harvard ont mis au point un cerveau multirégional sur une puce afin de comprendre comment les troubles mentaux impactent simultanément les régions du cerveau.

En savoir plus : Multiregional brain on a chip

Même si la plupart des technologies mentionnées dans ce Top 10 sont ou seront utilisées exclusivement par des médecins, il peut être intéressant de souligner que deux d’entre elles sont des applications mobiles utilisées par le patient. Trois si l’on tient compte des examens médicaux à distance. 

Comme nous l’avons mentionné dans l’article Santé numérique et innovations de première ligne publié dans le cadre de notre participation au Congrès des services de première ligne, une des tendances qui gagne de plus en plus en popularité en matière de santé numérique est l’implication du patient. L’idée est de déléguer aux patients certaines tâches qui ne nécessitent pas de formation en médecine ou qui s’accomplissent avec des instructions de base afin d’alléger le système de santé.

Avant d’envisager la démocratisation de technologies médicales actuellement en développement, il faut toutefois sensibiliser les professionnels de la santé à utiliser des technologies existantes qui ont déjà fait leurs preuves comme la prise de rendez-vous en ligne pour cliniques médicales ainsi que la création et la gestion numérique d’horaires de médecins.

Pour suivre l’évolution des tendances en matière de santé numérique, joignez-vous à la Communauté PetalMD!

GW190521: Unexpected Black Holes Collide - (Science & Technology - Astronomy picture of the day)

2020 September 8
GW190521: Unexpected Black Holes Collide 
Illustration Credit: Raúl Rubio (Virgo Valencia Group, The Virgo Collaboration)

Explanation: How do black holes like this form? The two black holes that spiraled together to produce the gravitational wave event GW190521 were not only the most massive black holes ever seen by LIGO and VIRGO so far, their masses -- 66 and 85 solar masses -- were unprecedented and unexpected. Lower mass black holes, below about 65 solar masses are known to form in supernova explosions. Conversely, higher mass black holes, above about 135 solar masses, are thought to be created by very massive stars imploding after they use up their weight-bearing nuclear-fusion-producing elements. How such intermediate mass black holes came to exist is yet unknown, although one hypothesis holds that they result from consecutive collisions of stars and black holes in dense star clusters. Featured is an illustration of the black holes just before collision, annotated with arrows indicating their spin axes. In the illustration, the spiral waves indicate the production of gravitational radiation, while the surrounding stars highlight the possibility that the merger occurred in a star cluster. Seen last year but emanating from an epoch when the universe was only about half its present age (z ~ 0.8), black hole merger GW190521 is the farthest yet detected, to within measurement errors.

Edvar Grieg (Peer Gynt) : "In the hall of the mountain king" - (Music - Live - Video)

Simon R. Hudson : The Milky Way over St Michael's Mount - (Science & Technology - Astronomy picture of the day)

2020 September 7
The Milky Way over St Michael's Mount 
Image Credit: Simon R. Hudson

Explanation: Where do land and sky converge? On every horizon -- but in this case the path on the ground leads to St Michael's Mount (Cornish: Karrek Loos yn Koos), a small historic island in Cornwall, England. The Mount is usually surrounded by shallow water, but at low tide is spanned by a human-constructed causeway. The path on the sky, actually the central band of our Milky Way Galaxy, also appears to lead to St Michael's Mount, but really lies far in the distance. The red nebula in the Milky Way, just above the castle, is theLagoon Nebula, while bright Jupiter shines to the left, and a luminous meteor flashes to the right. The foreground and background images of this featured composite were taken on the same July night and from the same location. Although meteors are fleeting and the Milky Way disk shifts in the night as the Earth turns, Jupiter will remain prominent in the sunset sky into December.