Sunshine Jumping With Flying Friends

Type 1a Supernovae: Why Our Standard Candle Isn’t Really Standard

By: Nadia Drake | National Geographic-Phenomena

When I joined Phenomena, Carl Zimmer asked: What obsesses you? Among my obsessions, I answered, are type 1a supernovae. Here we go.

How can an astronomical object of such crucial cosmological importance remain so fundamentally mysterious?

When a runaway thermonuclear explosion rips through a white dwarf star and blows the star to bits, it’s called a type 1a supernova. These explosions are incredibly violent and incredibly bright, sometimes outshining entire galaxies. Thought to occur about once every two centuries in a galaxy like the Milky Way, these stellar cataclysms are relatively frequent events.

HUBBLE UNCOVERS EXTREME GALAXY CALLED ‘SPARKY’

Astronomers have used the Hubble Space Telescope to observe a monster galaxy that was hidden behind walls of dust.

The discovery offers important clues about an early phase of galaxy development, from a time just 3 billion years after the Big Bang.

The research appears in the journal Nature.

Galaxy formation theories have suggested that the universe’s heaviest galaxies develop from the inside out, forming their star-studded, central cores during early cosmic epochs. But scientists had never been able to observe this core construction until now.

“It’s a formation process that can’t happen anymore,” says Erica Nelson, a Yale University graduate student who was lead author of the paper. “The early universe could make these galaxies, but the modern universe can’t.

“It was this hotter, more turbulent place—these were boiling cauldrons, forging stars.”