Oldest planetary debris in our galaxy found in new study

Astronomers led by the University of Warwick have identified the oldest star in our galaxy that is accreting debris from orbiting planetesimals, making it one of the oldest rocky and icy planetary systems discovered in the ...

No trace of dark matter halos

According to the standard model of cosmology, the vast majority of galaxies are surrounded by a halo of dark matter particles. This halo is invisible, but its mass exerts a strong gravitational pull on galaxies in the vicinity. ...

Family tree of the Milky Way deciphered

Scientists have known for some time that galaxies can grow by the merging of smaller galaxies, but the ancestry of our own Milky Way galaxy has been a long-standing mystery. Now, an international team of astrophysicists has ...

Astronomers discover how to feed a black hole

The black holes at the centers of galaxies are the most mysterious objects in the Universe, not only because of the huge quantities of material within them, millions of times the mass of the sun, but because of the incredibly ...

Gravitational lenses measure universe expansion

It's one of the big cosmology debates: The universe is expanding, but how fast exactly? Two available measurements yield different results. Leiden physicist David Harvey adapted an independent third measurement method using ...

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