In January 2002, a moderately dim star in the constellation Monoceros, the Unicorn, suddenly became 600 000 times more luminous than our Sun. This made it temporarily the brightest star in our Milky Way. The light from this eruption created a unique phenomenon known as a light echo when it reflected off dust shells around the star.
The brightness of V838 Monocerotis, as astronomers call the star, has long since returned to normal levels. Observations by the NASA/ESA Hubble Space Telescope show remarkable details in the shells of dust lit by the titanic stellar eruption. Astronomers may be able to probe the entire 3D structure of the dust shells surrounding this aging star in much the same way as a doctor does a CAT scan on a patient. The results will appear on 27 March 2003 in Nature.
Astronomers last saw light echoing off dust around stars in our Milky Way in 1936, long before Hubble was able to study this rare sight in the underworld of dusty, black interstellar space.
"As light from the outburst continues to reflect off the dust surrounding the star, we view continuously changing cross-sections of the dust envelope. Hubbles sharp view is allowing us to do astronomical tomography of the dust with unprecedented resolution." says the lead observer, astronomer Howard Bond of the Space Telescope Science Institute in the United States.
Lars Lindberg Christensen | alfa
Hope to discover sure signs of life on Mars? New research says look for the element vanadium
22.09.2017 | University of Kansas
22.09.2017 | Forschungszentrum MATHEON ECMath
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
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