Milky Way tagged posts

The Puzzle of the Galaxy with No Dark Matter

Dark matter-free galaxy NGC 1277, located near the centre of the Perseus cluster, 240 million light-years from Earth. Credit: NASA, ESA, and M. Beasley (IAC)

A team of scientists, led by the researcher at the IAC and the University of La Laguna (ULL) Sebastién Comerón, has found that the galaxy NGC 1277 does not contain dark matter. This is the first time that a massive galaxy (it has a mass several times that of the Milky Way) does not show evidence for this invisible component of the universe. “This result does not fit in with the currently accepted cosmological models, which include dark matter” explains Comerón.

In the current standard model cosmology massive galaxies contain substantial quantities of dark matter, a type of matter which does not interact in the same way as no...

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A Neutrino Portrait of our Galaxy reveals High-Energy Particles from within the Milky Way

Five views of the Milky Way: the top two bands show visible light and gamma rays, while the lower three show expected and real neutrino results, plus a measure of the significance of neutrino events detected by IceCube. IceCube Collaboration

Our Milky Way galaxy is an awe-inspiring feature of the night sky, viewable with the naked eye as a hazy band of stars stretching from horizon to horizon.

For the first time, the IceCube Neutrino Observatory in Antarctica has produced an image of the Milky Way using neutrinos—tiny, ghost-like astronomical messengers.

In research published June 29 in the journal Science, the IceCube Collaboration—an international group of more than 350 scientists—presents evidence of high-energy neutrino emission coming from the Milky Way.

We have not...

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Astronomers find ‘Gold Standard’ Star in Milky Way

The star HD 222925 is a ninth-magnitude star located toward the southern constellation Tucana. Image credit: The STScI Digitized Sky Survey

In our sun’s neighborhood of the Milky Way Galaxy is a relatively bright star, and in it, astronomers have been able to identify the widest range of elements in a star beyond our solar system yet.

The study, led by University of Michigan astronomer Ian Roederer, has identified 65 elements in the star, HD222925. Forty-two of the elements identified are heavy elements that are listed along the bottom of the periodic table of elements.

Identifying these elements in a single star will help astronomers understand what’s called the “rapid neutron capture process,” or one of the major ways by which heavy elements in the universe were created...

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Gaia Mission finds parts of the Milky Way Much Older than expected

Milky Way edge-on view

Using data from ESA’s Gaia mission, astronomers have shown that a part of the Milky Way known as the ‘thick disc’ began forming 13 billion years ago, around 2 billion years earlier than expected, and just 0.8 billion years after the Big Bang.

This surprising result comes from an analysis performed by Maosheng Xiang and Hans-Walter Rix, from the Max-Planck Institute for Astronomy, Heidelberg, Germany. They took brightness and positional data from Gaia’s Early Data Release 3 (EDR3) dataset and combined it with measurements of the stars’ chemical compositions, as given by data from China’s Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) for roughly 250 000 stars to derive their ages.

They chose to look at sub giant stars...

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