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    Category Astronomy/Space

    Astronomers see Stellar Self-Control in action

    November 30, 2022, Categories  Astronomy/Space

    Composite image of RCW 36.
    Credits: X-ray: NASA/CXC/Ames Research Center/L. Bonne et al.; Infrared: ESA/NASA.JPL-Caltech/Herschel Space Observatory/JPL/IPAC

    Many factors can limit the size of a group, including external ones that members have no control over. Astronomers have found that groups of stars in certain environments, however, can regulate themselves.

    A new study has revealed stars in a cluster having “self-control,” meaning that they allow only a limited number of stars to grow before the biggest and brightest members expel most of the gas from the system. This process should drastically slow down the birth of new stars, which would better align with astronomers’ predictions for how quickly stars form in clusters. A paper describing these results appeared in the Aug...

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    Hubble Glimpses a Glittering Gathering of Stars

    November 30, 2022, Categories  Astronomy/Space

    This glittering gathering of stars is Pismis 26, a globular star cluster located about 23,000 light-years away. Many thousands of stars gleam brightly against the black backdrop of the image, with some brighter red and blue stars located along the outskirts of the cluster. The Armenian astronomer Paris Pismis first discovered the cluster in 1959 at the Tonantzintla Observatory in Mexico, granting it the dual name Tonantzintla 2.

    Pismis 26 is located in the constellation Scorpius near the galactic bulge, which is an area near the center of our galaxy that holds a dense, spheroidal grouping of stars that surrounds a black hole...

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    Non-detection of Key Signal allows Astronomers to Determine what the First Galaxies were – and weren’t – like

    November 29, 2022, Categories  Astronomy/Space

    Observations by the NASA/ESA Hubble Space Telescope have taken advantage of gravitational lensing to reveal the largest sample of the faintest and earliest known galaxies in the universe.
    Early galaxies capture by the NASA/ESA Hubble Telescope
    Credit: NASA Goddard

    Researchers have been able to make some key determinations about the first galaxies to exist, in one of the first astrophysical studies of the period in the early Universe when the first stars and galaxies formed, known as the cosmic dawn.

    Using data from India’s SARAS3 radio telescope, researchers led by the University of Cambridge were able to look at the very early Universe — just 200 million years after the Big Bang — and place limits on the mass and energy output of the first stars and galaxies.

    Counterintuitively, the researchers were able to place these limits on the earliest galaxies by not finding the signal they had been looking for, known as the 21-centimetre hydrogen line.

    This non-detectio...

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    NASA’s IXPE helps Solve Black Hole Jet mystery

    November 25, 2022, Categories  Astronomy/Space

    This illustration shows NASA’s IXPE spacecraft, at right, observing blazar Markarian 501, at left. A blazar is a black hole surrounded by a disk of gas and dust with a bright jet of high-energy particles pointed toward Earth. The inset illustration shows high-energy particles in the jet (blue). When the particles hit the shock wave, depicted as a white bar, the particles become energized and emit X-rays as they accelerate. Moving away from the shock, they emit lower-energy light: first visible, then infrared, and radio waves. Farther from the shock, the magnetic field lines are more chaotic, causing more turbulence in the particle stream.
    Credits: NASA/Pablo Garcia

    Some of the brightest objects in the sky are called blazars...

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