Glowing Nebula's Clouds Look Like Giant Human Face in New Photo | NGC 3324, Nebulas & Star Formation | Space Photos & European Southern Observatory The wispy clouds of a distant nebula bursting with newborn stars take on an eerie face-like shape sculpted by stellar winds in a new photo snapped by a telescope in Chile. The hotbed of star birth, called NGC 3324, is full of hot young stars, whose ultraviolet radiation is making the gas clouds glow. The stellar wind and radiation from the newborn stars has also punched out a cavity in the surrounding gas and dust. The edge of the wall of gas and dust at the right in the photo resembles the profile of a human face, with a ridge in the center that looks like a nose. Astronomers often attach nicknames to nebulas based on their shape and their earthly likenesses. The new image was captured by the Wide Field Imager on the MPG/ESO 2.2-meter telescope at the European Southern Observatory's (ESO) La Silla Observatory in Chile's Atacama Desert. Strong stellar winds and intense ultraviolet radiation from these young stars have carved out a pocket in the nearby gas and dust.
Record : une galaxie 380 millions d'années après le Big Bang ? Un groupe d’astronomes a découvert 7 galaxies parmi les plus lointaines connues, observées sur une période s’étendant entre 350 et 600 millions d’années après le Big Bang . L’une d’entre elles pourrait même détenir un record. Hubble la montre peut-être alors que le cosmos n’avait que 380 millions d’années. Cela fait 9 ans que les astronomes étudient le Hubble Ultra Deep Field (HUDF). De 2003 à 2004, les instruments de Hubble ont observé pendant plusieurs heures, réparties sur une durée de 11 jours au total, une petite région de la voûte céleste située dans la constellation du Fourneau. Les astrophysiciens avaient ainsi obtenu une image dans le visible sur laquelle se trouvaient à la fois des galaxies proches et les plus anciennes connues à l’époque. Un groupe d’astronomes vient de publier un article sur arxiv portant sur des observations d’une partie du HUDF dans l’infrarouge proche pendant 6 semaines, d’août à septembre 2012. Le bilan de l' Hubble Ultra Deep Field 2012 est arrivé
Alien Life Unlikely Around White and Brown Dwarfs, Study Finds The dead and failed stars known as white dwarfs and brown dwarfs can give off heat that can warm up worlds, but their cooling natures and harsh light make them unlikely to host life, researchers say. Stars generally burn hydrogen to give off light and heat up nearby worlds. However, there are other bodies in space that can shine light as well, such as the failed stars known as brown dwarfs and the dead stars known as white dwarfs. White dwarfs are remnants of normal stars that have burned all the hydrogen in their cores. Still, they can remain hot enough to warm nearby planets for billions of years. Brown dwarfs are gaseous bodies that are larger than the heaviest planets but smaller than the lightest stars. Still, the gravitational energy from their contractions does get converted to heat, meaning they can warm their surroundings. An added benefit of looking for exoplanets around these dwarfs is that they might be easier to detect than ones around regular stars. Shifting habitable zones
Ghostly gamma-ray beams blast from Milky Way's center (Phys.org) -- As galaxies go, our Milky Way is pretty quiet. Active galaxies have cores that glow brightly, powered by supermassive black holes swallowing material, and often spit twin jets in opposite directions. In contrast, the Milky Way's center shows little activity. But it wasn't always so peaceful. New evidence of ghostly gamma-ray beams suggests that the Milky Way's central black hole was much more active in the past. "These faint jets are a ghost or after-image of what existed a million years ago," said Meng Su, an astronomer at the Harvard-Smithsonian Center for Astrophysics (CfA), and lead author of a new paper in the Astrophysical Journal. "They strengthen the case for an active galactic nucleus in the Milky Way's relatively recent past," he added. The two beams, or jets, were revealed by NASA's Fermi space telescope. The newfound jets may be related to mysterious gamma-ray bubbles that Fermi detected in 2010. The two structures also formed differently.
Explornova - Galaxies Description : Avant 1923, on croyait que l'univers se limitait à la Voie lactée, littéralement en grec la Galaxias ou Galaxie en français. Depuis les découvertes d’Edwin Hubble en 1929, de nombreux objets nébuleux sont devenus d’autres galaxies. Une galaxie est si grande qu’il nous faudrait des centaines de milliers d’années pour la traverser si nous pouvions voyager à la vitesse de la lumière, soit environ 300 000 km par seconde. Non seulement c’est extrêmement long, mais nous sommes aussi très loin d’atteindre une telle vitesse de voyage. Nous observons donc notre chère Voie Lactée depuis la Terre. Alors qu’il est difficile d’observer et de comprendre la forme de notre galaxie puisque nous sommes dedans, nous pouvons facilement observer d’autres galaxies dans l’Univers.
This date in science: Baily's Beads discovered | Space May 15, 1836. On this date, Francis Baily, an English astronomer, saw beads of sunlight shining along the edge of the moon’s silhouette during an eclipse of the sun. It was an annular eclipse – nowadays often called a ring of fire eclipse – meaning that the moon was too far away in its monthly orbit around Earth to appear large enough in our sky to cover the sun completely. Baily’s Beads are beads of sunlight – caused when sunlight shines between mountains and other features on the moon – seen during the February 16, 1991 annular solar eclipse. Another shot of Bailey’s Beads from the February 16, 1999 ecilpse via Fred Espenak. Francis Baily, pre-1844, via Wikimedia Commons This phenomenon became known as Baily’s Beads, and it can be seen during total eclipses, too, just before the moon covers the sun completely. Baily published his discovery in the Monthly Notices of the Royal Astronomical Society in December of that year.
Astronomers estimate 100 billion habitable Earth-like planets in the Milky Way, 50 sextillion in the universe Astronomers at the University of Auckland claim that there are actually around 100 billion habitable, Earth-like planets in the Milky Way — significantly more than the previous estimate of around 17 billion. There are roughly 500 billion galaxies in the universe, meaning there is somewhere in the region of 50,000,000,000,000,000,000,000 (5×1022) habitable planets. I’ll leave you to do the math on whether one of those 50 sextillion planets has the right conditions for nurturing alien life or not. The previous figure of 17 billion Earth-like planets in the Milky Way came from the Harvard-Smithsonian Center for Astrophysics in January, which analyzed data from the Kepler space observatory. Kepler essentially measures the dimming (apparent magnitude) of stars as planets transit in front of them — the more a star dims, the larger the planet. Gravitational microlensing, an effect theorized by Einstein back in 1936, is exactly what it sounds like.
Groupe local Le Groupe local de galaxies[1] ou, plus simplement, le Groupe local[2] est le groupe de plus de 60 galaxies auquel appartient la Voie lactée[3],[4],[5]. Son diamètre est d’environ 3 millions de parsecs (soit environ 10 millions d'années-lumière). Le Groupe local semble être un représentant typique des groupes de galaxies qui se trouvent dans l’univers. Il possède à peu près tous les types usuels de galaxies, à l’exception des galaxies elliptiques géantes qui ne sont jamais présentes dans des structures aussi petites. Voici une localisation des principales galaxies du Groupe local : Carte interactive du Groupe local. Historique[modifier | modifier le code] D'après l'historien des sciences américain Steven J. L'expression est reprise, dès 1936, par l’astronome américain Edwin Hubble, dans le chapitre VI de son ouvrage The Realm of Nebulae[8]. Caractéristiques[modifier | modifier le code] Les autres membres du Groupe local sont gravitationnellement indépendants de ces larges sous-groupes.
Orion's hidden fiery ribbon | Science Wire This orange glow represents faint light coming from grains of cold interstellar dust, at wavelengths too long for human eyes to see. It was observed by the ESO-operated Atacama Pathfinder Experiment (APEX) in Chile. Clouds of gas and interstellar dust are the raw materials from which stars are made. But these tiny dust grains block our view of what lies within and behind the clouds — at least at visible wavelengths — making it difficult to observe the processes of star formation. View Larger | This wide-field view shows a region of sky in the famous constellation of Orion (The Hunter), as seen in visible light. The large, bright feature at the top of the image is the well-known Orion Nebula (Messier 42). This is why astronomers need to use instruments that are able to see at other wavelengths of light. This spectacular new picture shows just a part of a bigger complex called the Orion Molecular Cloud, in the constellation of Orion (The Hunter). Via ESO
Voie lactée La Voie lactée, aussi nommée la Galaxie (avec une majuscule), est une galaxie spirale barrée qui comprend entre 200 et 400 milliards d'étoiles, et sans doute plus de 100 milliards de planètes. Elle abrite le Système solaire et donc la Terre. Son diamètre est estimé à 100 000 à 120 000 années-lumière, voire à 150 000 ou à 200 000 années-lumière, bien que le nombre d'étoiles au-delà de 120 000 années-lumière soit très faible. Son cortège de galaxies satellites et elle font partie du Groupe local, lui-même rattaché au superamas de la Vierge appartenant lui-même à Laniakea. Le Système solaire se situe à environ 27 000 années-lumière du centre de la Voie lactée, lequel est constitué d'un trou noir supermassif. Étymologie et histoire du nom[modifier | modifier le code] Cette désignation trouve son origine dans la mythologie grecque : dans le récit le plus courant, Zeus, désirant rendre Héraclès immortel, lui fait téter le sein d'Héra alors endormie. = -30°[44],[45].
A hidden population of exotic neutron stars | Science Wire Magnetars – the dense remains of dead stars that erupt sporadically with bursts of high-energy radiation – are some of the most extreme objects known in the Universe. A major campaign using NASA’s Chandra X-ray Observatory and several other satellites shows magnetars may be more diverse – and common – than previously thought. When a massive star runs out of fuel, its core collapses to form a neutron star, an ultradense object about 10 to 15 miles wide. The gravitational energy released in this process blows the outer layers away in a supernova explosion and leaves the neutron star behind. Most neutron stars are spinning rapidly – a few times a second – but a small fraction have a relatively low spin rate of once every few seconds, while generating occasional large blasts of X-rays. A magnetar called SGR 0418+5729 (SGR 0418 for short) has been shown to have the lowest surface magnetic field ever found for this type of neutron star. Via Chandra X-Ray Observatory