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Unveiling the formation of the first galaxies

Utilizing high-resolution three-dimensional radiation hydrodynamics simulations and a detailed supernova physics model run on supercomputers, a research team led by Dr. Ke-Jung Chen from the Institute of Astronomy and Astrophysics, ...

Cosmic dawn observational progress with NenuFAR

The NenuFAR Cosmic Dawn project has taken an important step in the exploration of the Cosmic Dawn, this key period in our universe marked by the formation of the first stars. An upper limit on the amplitude of the neutral ...

Webb telescope catches early galaxy formation in action

Astronomers from the Cosmic Dawn Center have unveiled the nature of the densest region of galaxies seen with the James Webb Space telescope in the early universe. They find it to be likely the progenitor of a massive, Milky ...

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Dawn is the time that marks the beginning of the twilight before sunrise. It is recognized by the presence of weak sunlight, while the sun itself is still below the horizon. Dawn should not be confused with sunrise, which is the moment when the leading edge of the sun itself appears above the horizon.

The duration of the twilight period between dawn and sunrise varies greatly depending on the observer's latitude, from a few minutes in equatorial regions to many hours in polar regions. Dawn may easily be determined by observing a thread. When the color of a thread can be determined, changing from black to the thread's distinctive color, the 'crack of dawn' has occurred. This same measure of ambient light can be used to determine, conversely, the instant of dusk.

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