Archiv: interstellar (galactic) magnetic field


02.01.2020 - 17:18 [ ORF.at ]

„Magnetische Wand“ im interstellaren Raum

(04.11.2019)

„Voyager 2“ hat die Grenze der Heliosphäre in nur einem Tag passiert, was einen scharfen Übergang zum lokalen interstellaren Medium bedeutet. „Die alte, historische Vorstellung, dass der Sonnenwind sich einfach allmählich reduziert, je weiter man in den interstellaren Raum vordringt, trifft nicht zu“, erläuterte „Voyager“-Forscher Don Gurnett von der Universität von Iowa, Ko-Autor einer der Analysen. „Wir haben mit ‚Voyager 2‘ und vorher mit ‚Voyager 1 gezeigt, dass es dort draußen eine ausgeprägte Grenze gibt.“

04.11.2019 - 19:38 [ ScienceNews.org ]

Voyager 2 reveals the dynamic, complex nature of the solar system’s edge

Despite encountering the heliopause at different times and locations — the two spacecraft are farther from each other than each are from the sun — some things looked similar. The magnetic field looked pretty much the same on the inside and the outside of the boundary: Somehow, the sun’s magnetic field lines up nearly perfectly with the local galactic field, contrary to expectations. “We could dismiss that as coincidence in one case, but we can’t do that twice,” study coauthor Leonard Burlaga, of NASA’s Goddard Space Flight Center in Greenbelt, Md., said in the news conference.

04.11.2019 - 19:30 [ Nature ]

Energetic charged particle measurements from Voyager 2 at the heliopause and beyond

Here, we report measurements of energetic (>28 keV) charged particles on V2 from the interface region between the heliosheath, dominated by heated solar wind plasma, and the VLISM, expected to contain cold non-solar plasma and the Galactic magnetic field. The number of particles of solar origin began a gradual decrease on 7 August 2018 (118.2 au), while those of Galactic origin (Galactic cosmic rays) increased ~20% in number over a period of a few weeks. An abrupt change occurred on 5 November when V2 was located at 119 au, with a decrease in the number of particles at energies of >28 keV and a corresponding increase in the number of Galactic cosmic rays of energy E > 213 MeV. T

04.11.2019 - 19:19 [ theGuardian.com ]

Nasa’s Voyager 2 sends back its first signal from interstellar space

The shape depends, in a complex way, on the relative strengths of the magnetic fields inside and outside of the heliosphere, and the latest measurements are suggestive of a more spherical form.

04.11.2019 - 18:51 [ ORF ]

„Magnetische Wand“ im interstellaren Raum

Nach Jahrzehnten haben sie nun die Grenze der Heliosphäre passiert und sind damit auf dem Weg zu den Sternen.

30.05.2019 - 16:24 [ scitecheuropa.eu ]

Solving a century-long mystery: the origin of galactic cosmic rays

(04.04.2019)

The word ‘astronomy’ means the direct observations of extra-terrestrial objects. This definition is relevant to photons, neutrinos, and gravitational waves, i.e. massless, neutral and stable particles. But for cosmic ray electrons, protons, and nuclei, the term ‘astronomy’ is used with a certain reservation. Because of the deflections of electrically charged particles in the chaotic interstellar and intergalactic magnetic fields, the information about their original directions pointing to the sites of their production is lost. Instead, on the Earth, we detect an (almost) isotropic flux of cosmic rays contributed by a huge number of galactic and extragalactic sources.