Archiv: stars (space objects)


04.10.2021 - 07:04 [ National Astronomical Observatory of Japan / SciTechdaily.com ]

Interplay Between Magnetic Force and Gravity in Massive Star Formation

(September 26, 2021)

The magnetic field is part of one of the four fundamental forces in nature. It plays a vital role in everyday life, from producing electricity in hydroelectric power plants to diagnosing diseases in medicine. Historically, the Earth’s magnetic field served as a compass for travelers before modern technology was available. Crucially for life, the Earth’s magnetic field acts as a shield protecting us from charged particles emanating from the Sun, which are accelerated by the Sun’s magnetic field. Removing this shield would very likely extinguish life on Earth.

20.02.2021 - 12:20 [ Jet Propulsion Laboratory / NASA.gov ]

Using Light to Study Planets

In this activity, students will build a spectrometer using basic materials to observe the light emitted and absorbed by several sources. This will be used as a model for how NASA uses spectroscopy to determine the nature of elements found on Earth and other planets. For higher grades, this activity can also be used to discuss advanced spectroscopic topics, such as how NASA research is advancing spectroscopic techniques to teach us more about plant life on Earth.

14.05.2020 - 20:45 [ inverse.com ]

The Sun‘s midlife crisis could be making it stand out in the universe

(30.04.2020)

„The solar dynamo is one of the last unsolved mysteries of solar physics,“ Reinhold says. „We don’t really know why it’s 11 years long, or how it is generated.“

Other stars also run on cycles, but theirs varies from three years to eight years.

Although the researchers aren‘t quite sure what makes the Sun so unique, they have a few possible explanations.

14.05.2020 - 20:37 [ Forbes ]

Is Our Sun In A 9,000 Year ‘Feeble Phase?’ Similar Stars Are Five Times More Fickle, Find Scientists

(30.04.2020)

The Sun takes 24.5 days to rotate once around their own axis; the 369 chosen all rotate once every 20-30 days.

“The speed at which a star rotates around its own axis is a crucial variable,” said Prof. Dr. Sami Solanki, director at MPS and co-author of the new paper. “The magnetic field is the driving force responsible for all fluctuations in activity.”

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.

15.11.2019 - 15:31 [ Carnegie Science / Youtube ]

Hypervelocity star

(12.11.2019)

The artist impression of the ejection mechanism by the supermassive black hole. Credit: James Josephides (Swinburne Astronomy Productions)

15.11.2019 - 15:21 [ Carnegie Science ]

Runaway star was ejected from the “heart of darkness”

“My favorite part of this discovery is thinking about where this star came from and where it‘s going,” said Ji. “It was born in one of the craziest places in the universe, near a supermassive black hole with lots of other nearby star friends; but it‘s going to leave our galaxy and die all alone, out in the middle of nowhere. Quite a fall from grace.”

15.11.2019 - 15:06 [ CBS News ]

Supermassive black hole throws star out of Milky Way galaxy at speed of 3.7 million mph

Five million years ago, when humanity‘s ancestors were just learning to walk upright, a star was ejected from Sagittarius A*, the supermassive black hole at the center of the Milky Way Galaxy, at a staggering 3.7 million mph. This month, a group of researchers spotted the superfast star traveling relatively close to Earth.

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.

30.05.2019 - 16:11 [ arxiv.org ]

Hypothesis: Muon Radiation Dose and Marine Megafaunal Extinction at the end-Pliocene Supernova

(November 2018)

Considerable data and analysis support the detection of one or more supernovae (SNe) at a distance of about 50 pc, ∼2.6 million years ago. This is possibly related to the extinction event around that time and is a member of a series of explosions that formed the Local Bubble in the interstellar medium. We build on previous work, and propagate the muon flux from SN-initiated cosmic rays from the surface to the depths of the ocean. We find that the radiation dose from the muons will exceed the total present surface dose from all sources at depths up to 1 km and will persist for at least the lifetime of marine megafauna. It is reasonable to hypothesize that this increase in radiation load may have contributed to a newly documented marine megafaunal extinction at that time.

25.05.2019 - 14:36 [ NASA Solar System ‏/ Twitter ]

The Space Between: interstellar space is often called the space between the stars, but more specifically, it’s the region between our Sun’s heliosphere and the astrospheres of other stars. Find out how that works

(27.03.2019)

29.04.2019 - 10:50 [ Phys.org ]

Rapid destruction of Earth-like atmospheres by young stars

(24.04.2019)

The high energy radiation is important because it is absorbed high in the atmosphere of a planet, causing the gas to be heated. For the Earth, the gas is heated to temperatures of more than 1000 degrees Celsius in the upper region known as the thermosphere. This is the region in which spacecraft such as satellites and the International Space Station fly. When orbiting young stars with high activity levels, the thermospheres of planets are heated to much higher temperatures which, in extreme cases, can cause the gas to flow away from the planet.

07.08.2018 - 15:40 [ China.org.cn ]

Chinese astronomers discover giant star rich in lithium

With 3,000 times more lithium than a normal star, it was found in the direction of Ophiuchus, on the north side of the galactic disk, at a distance of 4,500 light years from Earth.