The SECCHI team has obtained images of the density enhancements whose prior existence was known only from point measurements by in situ spacecraft. The team’s results will be discussed during an invited talk by Dr. Neil Sheeley of the Naval Research Laboratory (NRL) at the fall meeting of the American Geophysical Union in San Francisco, CA, in December. The scientific paper is scheduled for publication in the March 1, 2008 issue of the Astrophysical Journal.
During relatively quiet solar conditions throughout the spring and summer of 2007, the SECCHI Heliospheric Imager HI-2 telescope on the STEREO B solar-orbiting spacecraft observed a succession of wavefronts sweeping past Earth. The scientists have compared these white-light images with in situ plasma and magnetic ?eld measurements obtained by near-Earth spacecraft, and found a perfect association between the occurrence of these waves and the arrival of high-density regions that rotate with the Sun. These compression regions are believed to form as high-speed wind from dark areas of the solar corona known as coronal holes run into the low-speed wind in front of it.
Currently, the researchers are tracking HI-2 waves backward toward the Sun to see exactly how they originate. Preliminary results suggest that the waves begin as blobs of material that are shed continuously from coronal streamers.
The STEREO twin spacecraft were launched on October 25, 2006 with the objective of obtaining stereoscopic observations of the Sun from a near-Earth orbit. After some initial maneuvers, which included a gravitational assist from the moon, the two spacecraft achieved their orbits with one spacecraft (A) located slightly closer to the Sun and gradually moving ahead of Earth and the other spacecraft (B) located slightly farther from the Sun and gradually falling behind. The angular distance between the A and B spacecraft increases at a rate of approximately 45 degrees per year and was about 26 degrees in early September 2007.
Each spacecraft is equipped with a suite of Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) instruments. In addition to an extreme ultraviolet imager (EUVI), there are two coronagraphs (COR1 and COR2) and two heliospheric imagers (HI-1 and HI-2) pointing 13 degrees and 53 degrees off to the side.
Janice Schultz | EurekAlert!
Organic light-emitting diodes become brighter and more durable
28.05.2018 | Technische Universität Dresden
APEX takes a glimpse into the heart of darkness
25.05.2018 | Max-Planck-Institut für Radioastronomie
The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.
Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
28.05.2018 | Event News
25.05.2018 | Event News
02.05.2018 | Event News
28.05.2018 | Trade Fair News
28.05.2018 | Physics and Astronomy
28.05.2018 | Event News