Astronomers using NASA’s Swift satellite recently detected a rise in high-energy X-rays from a source toward the center of our Milky Way galaxy. The outburst, produced by a rare X-ray nova, came from a previously unknown stellar-mass black hole.
An X-ray nova is a short-lived X-ray source that appears suddenly, reaches its emission peak in a few days and then fades out over a period of months. The outburst arises when a torrent of stored gas suddenly rushes toward one of the most compact objects known, either a neutron star or a black hole.
The rapidly brightening source triggered Swift’s Burst Alert Telescope twice on the morning of Sept. 16, and once again the next day. Named Swift J1745-26 after the coordinates of its sky position, the nova is located a few degrees from the center of our galaxy toward the constellation Sagittarius. While astronomers do not know its
precise distance, they think the object resides about 20,000 to 30,000 light-years away in the galaxy’s inner region.
Ground-based observatories detected infrared and radio emissions, but thick clouds of obscuring dust have prevented astronomers from catching Swift J1745-26 in visible light.
From NASA’s legendary Scientific Visualization Studio, here’s news of one of the nearest and richest stellar associations in our galaxy. Cygnus OB2, located about 4,700 light-years away, hosts some 3,000 hot stars, including about 100 in the O class. Weighing in at more than a dozen times the sun’s mass and sporting surface temperatures five to ten times hotter, these ginormous blue-white stars blast their surroundings with intense ultraviolet light and powerful outflows called stellar winds.
Two of these stars can be found in the intriguing binary system known as Cygnus OB2 #9. In 2011, NASA’s Swift satellite, the European Space Agency’s XMM-Newton observatory and several ground-based facilities took part in a campaign to monitor the system as the giant stars raced toward their closest approach. The observations are giving astronomers a more detailed picture of the stars, their orbits and the interaction of their stellar winds.
An O-type star is so luminous that the pressure of its starlight actually drives material from its surface, creating particle outflows with speeds of several million miles an hour. Put two of these humongous stars in the same system and their winds can collide during all or part of the orbit, creating both radio emission Continue reading Battle of Giant Windy Stars→
This video explores the most basic question of all: why we explore space? Be sure to experience the visual spectacle in full HD, 1080P.
The Mars rover, Curiosity, is the latest in a long line of missions to Mars: landers sent to scoop its soil and study its rocks, orbiters sent to map its valleys and ridges.
They are all asking the same question. Did liquid water once flow on this dry and dusty world? Did it support life in any form? And are there remnants left to find? The science that comes out of these missions may help answer a much larger, more philosophical question.
Is our planet Earth the norm, in a galaxy run through with life-bearing planets? Or is Earth a rare gem, with a unique make-up and history that allowed it to give rise to living things? On Mars, Curiosity has spotted pebbles and other rocks commonly associated with flowing water.
It found them down stream on what appears to be an ancient river fan, where water flowed down into Gale Crater. This shows that at some point in the past, Mars had an atmosphere, cloudy skies, and liquid water flowing. So what could have turned it into the Continue reading Why Mars Died, and Earth Lived→
These exquisite images are a must see at full resolution. Space imagery from NASA’s Conceptual Image Lab. An elegant interaction powers the sun, producing the light and energy that makes life possible. That interaction is called fusion, and it naturally occurs when two atoms are heated and compressed so intensely that their nuclei merge into a new element. This process often leads to the creation of a photon, the particles of light that are released from the sun.
However, before exiting our star, each photon must first undergo a long journey. Over the course of 40,000 years it will be absorbed by other atoms and emitted repeatedly until reaching the sun’s surface. Once there, the photons stream out, illuminating Earth, the solar system and beyond. The number released from the surface every second is so vast that it is more than a billion billion times greater than the number of grains of sand on our planet.
This movie takes us on a space weather journey from the center of the sun to solar eruptions in the sun’s atmosphere all the way to the effects of that activity near Earth. The view starts in the core of the sun where atoms fuse Continue reading Light from the Core of the Sun→
From HubbleCast and host Dr. J. Astronomers using the NASA/ESA Hubble Space Telescope have studied a giant filament of dark matter in 3D for the first time. Extending 60 million light-years from one of the most massive galaxy clusters known, the filament is part of the cosmic web that constitutes the large-scale structure of the Universe, and is a leftover of the very first moments after the Big Bang.
The theory of the Big Bang predicts that variations in the density of matter in the very first moments of the Universe led the bulk of the matter in the cosmos to condense into a web of tangled filaments. This view is supported by computer simulations of cosmic evolution, which suggest that the Universe is structured like a web, with long filaments that connect to each other at the locations of massive galaxy clusters. However, these filaments, although vast, are made mainly of dark matter, which is incredibly difficult to observe.
The first convincing identification of a section of one of these filaments was made earlier this year. Now a team of astronomers has gone further by probing a filament’s structure in three dimensions. Seeing a filament in 3D eliminates many of Continue reading Dark Matter Structure Revealed→
European astronomers have discovered a planet with about the mass of the Earth orbiting a star in the Alpha Centauri system — the nearest to Earth. It is also the lightest exoplanet ever discovered around a star like the Sun.
Alpha Centauri is one of the brightest stars in the southern skies and is the nearest stellar system to our Solar System — only 4.3 light-years away. It is actually a triple star — a system consisting of two stars similar to the Sun orbiting close to each other, designated Alpha Centauri A and B, and a more distant and faint red component known as Proxima Centauri. Since the nineteenth century astronomers have speculated about planets orbiting these bodies, the closest possible abodes for life beyond the Solar System, but searches of increasing precision had revealed nothing. Until now.
The European team detected the planet by picking up the tiny wobbles in the motion of the star Alpha Centauri B created by the gravitational pull of the orbiting planet . The effect is minute — it causes the star to move back and forth by no more than 51 centimetres per second (1.8 km/hour), about the speed of a baby crawling. This Continue reading Earth-sized Planet Found Orbiting the Sun’s Nearest Neighbor→
From NASA. A comprehensive study of hundreds of galaxies observed by the Keck telescopes in Hawaii and NASA’s Hubble Space Telescope has revealed a surprising pattern to galaxy evolution that extends back 8 billion years, or more than half the age of the universe.
Astronomers thought disk galaxies in the nearby universe had settled into their present form by about 8 billion years ago, with little additional development since. The trend observed shows the opposite, that galaxies were steadily changing over this time period. Today, star-forming galaxies take the form of orderly disk-shaped systems, such as the Andromeda Galaxy or the Milky Way, where rotation dominates over other internal motions. The most distant blue galaxies in the study tend to be very different, exhibiting disorganized motions in multiple directions. There is a steady shift toward greater organization to the present time as the disorganized motions dissipate and rotation speeds increase. These galaxies are gradually settling into well-behaved disks.
Blue galaxies — their color indicates stars are forming within them — show less disorganized motions and ever-faster rotation speeds the closer they are observed to the present. This trend holds true for galaxies of all masses, but the most massive systems always show Continue reading The Turbulent Story of Galaxy Evolution→
Check out this very recent new activity from Hawaii’s Kilauea Volcano. Just as the activity is rising, we’re learning more about its deeper patterns. A new study finds that a deep connection about 50 miles underground can explain the enigmatic behavior of two of Earth’s most notable volcanoes, Hawaii’s Mauna Loa and Kilauea. The study, the first to model paired volcano interactions, explains how a link in Earth’s upper mantle could account for Kilauea and Mauna Loa’s competition for the same deep magma supply and their simultaneous “inflation,” or bulging upward, during the past decade.
The research offers the first plausible model that can explain both the opposing long-term eruptive patterns at Mauna Loa and Kilauea — when one is active the other is quiet — as well as the episode in 2003-2007 when GPS records showed that each bulged notably due to the pressure of rising magma. The study was conducted by scientists at Rice University, the University of Hawaii, the U.S. Geological Survey (USGS) and the Carnegie Institution of Washington.
From NASA and Bela Lugosi. An enormous alien planet that some astronomers thought was dead and buried has come back to life, a new study suggests. A new analysis of observations from NASA’s Hubble Space Telescope found that the bright nearby star Fomalhaut does indeed host a huge exoplanet, which scientists dubbed a “zombie” world in an aptly Halloween-themed video on the alien planet. This conclusion contradicts other recent studies, which determined that the so-called planet — known as Fomalhaut b — is actually just a giant dust cloud.
“Given what we know about the behavior of dust and the environment where the planet is located, we think that we’re seeing a planetary object that is completely embedded in dust rather than a free-floating dust cloud,” co-author John Debes, of the Space Telescope Science Institute in Baltimore, said in a statement.