Archiv: supernovae (star explosions / implosions)


26.04.2024 - 02:52 [ Space.com ]

Earth got hammered by cosmic rays 41,000 years ago due to a weak magnetic field

(24 April 2024)

The question is, Do periods of low magnetosphere intensity also correlate with major upheavals in Earth‘s biosphere, the complete zone of our planet over which life exists, ranging from mountaintops to the deepest ocean trenches?

„Understanding these extreme events is important for their occurrence in the future, space climate predictions, and assessing the effects on the environment and on the Earth system,“ Sanja Panovska, a scientist at GFZ Potsdam in Germany, said in a statement.

01.07.2023 - 16:32 [ Physics & Astronomy International Journal / medcraveonline.com ]

About the nature of gravitational and gravity waves

(March 20, 2018)

Gravitational waves, which Albert Einstein predicted in 1916.2 were a riddle until 14 September 2015. Gravitational waves are small deformations of the four dimensional space–time geometry. They propagate with the speed of light and they are generated by catastrophic events in the Universe, in which strong gravitational fields and sudden acceleration (or deceleration) of asymmetric distribution of large masses are involved. In the other words, according to the theory of relativity, any accelerating or decelerating massive object that isn’t spherically or cylindrically symmetrical generates detectable gravitational waves. That object could be for example neutron star or black hole binary system. Gravitational waves are also produced by cosmological explosions such as supernova. Gravity is the weakest of the four fundamental forces, it is known for a very long time, but still there is no a good unique gravity force (field) theory.

25.10.2021 - 18:59 [ National Aeronautics and Space Administration ]

Studying the Edge of the Sun’s Magnetic Bubble

(Oct 19, 2021)

The space radiation that comes at us from other stars is called galactic cosmic radiation (GCR). Active areas in the galaxy – like supernovae, black holes, and neutron stars – can strip the electrons from atoms and accelerate the nuclei to almost the speed of light, producing GCR.

On Earth, we have three layers of protection from space radiation. The first is the heliosphere, which helps block GCR from reaching the major planets in the solar system. Additionally, Earth’s magnetic field produces a shield called the magnetosphere, which keeps GCR out away from Earth and low-orbiting satellites like the International Space Station. Finally, the gases of Earth’s atmosphere absorb radiation.

22.09.2021 - 19:40 [ ORF ]

Riesiger Hohlraum im All entdeckt

Bei der Erstellung dreidimensionaler Karten in der Milchstraße haben Astrophysiker und Astrophysikerinnen einen riesigen Hohlraum entdeckt. Das kugelförmige Gebilde hat einen Durchmesser von rund 500 Lichtjahren.

17.04.2021 - 04:46 [ CNN ]

Giant radio pulses and X-ray surges are coming from the Crab Nebula

The light from this supernova first reached Earth in July 1054 and was witnessed by astronomers in Japan and China.

When the star exploded, it formed a neutron star, which is the dense core of a star that is about the size of a city like Chicago. This became a pulsar, or rapidly spinning neutron star, that is now located in the nebula.

15.09.2020 - 20:05 [ Informationsdienst Wissenschaft ]

P-ONE: Neues Observatorium im Pazifik für hochenergetische kosmische Neutrinos

Astronomen beobachten das Licht, das von entfernten Himmelsobjekten zu uns kommt, um das Universum zu erkunden. Licht verrät jedoch nichts über hochenergetische Ereignisse außerhalb unserer Galaxie, wie etwa über die Jets aktiver galaktischer Kerne, Gammastrahlenausbrüche oder Supernovae. Denn auf ihrem langen Weg durch das Universum verlieren Photonen mit extrem hohen Energien einen Teil ihrer Energie durch Interaktion mit anderen Teilchen.

24.08.2020 - 12:02 [ Heise.de ]

Beteigeuze wird schon wieder dunkler: Neuer Erklärungsversuch

(13.08.2020)

Zwischenzeitlich kam er nur auf 40 Prozent seiner normalen Helligkeit und hatte damit unter anderem Spekulationen genährt, dass sein Ende in einer gigantischen Explosion bevorstehen könnte. Immerhin ist unstrittig, dass er am Ende seines Lebens angekommen ist und in astronomisch naher Zukunft in einer immensen Supernova enden wird. Die wäre am Nachthimmel so hell wie ein Halbmond. Ende Februar begann er aber wieder heller zu werden, im späten Frühling war er wieder so hell wie früher.

24.08.2020 - 12:01 [ National Aeronautics and Space Administration ]

NASA Satellite’s Lone View of Betelgeuse Reveals More Strange Behavior

(13.08.2020)

STEREO’s measurements revealed that Betelgeuse is dimming again — an unexpected development so soon after its last dim period. Betelgeuse typically goes through brightness cycles lasting about 420 days, with the previous minimum in February 2020, meaning this dimming is happening unexpectedly early. These observations were reported by the science team via The Astronomer’s Telegram on July 28, 2020. This is an intriguing phenomenon that scientists will study with additional Earth-orbiting and ground-based observatories when Betelgeuse returns to the night sky in late August.

16.04.2020 - 03:18 [ Nature Astronomy ]

An extremely energetic supernova from a very massive star in a dense medium

Here we present a new event, SN2016aps, offset from the centre of a low-mass galaxy, that radiated ≳5 × 1051 erg, necessitating a hyper-energetic supernova explosion.

09.01.2020 - 19:38 [ Sueddeutsche ]

Steht eine Supernova in der kosmischen Nachbarschaft bevor?

Der auf Deutsch wegen eines historischen Schreibfehlers oft Beteigeuze genannte Riesenstern bildet die linke Schulter des Sternbilds Orion. In dieser Konstellation ist er derzeit nur der zweithellste Stern. Doch das könnte sich bald ändern.

02.01.2020 - 17:17 [ CNN ]

Why the world is waiting for Betelgeuse to go supernova

(01.01.2020)

If Betelgeuse does go supernova, it will be the brightest star in the sky for many months. (Except for the sun, of course.) It will even be visible during the day.

27.12.2019 - 21:06 [ CNN ]

A giant red star is acting weird and scientists think it may be about to explode

The red supergiant would glow a vibrant blue for three of four months, and would take about a year to fade out.

„It would be a really bright star visible in the daytime,“ Guinan said.

There wouldn‘t be any direct danger to life on earth, but ultraviolet radiation from the celestial blast could scorch ozone in our atmosphere.