protostars

What is a Protostar?

When gravity begins to pull a cloud of dust and mass together in a nebula—Increasingly hotter as the cloud collapses

what would be required for a collapsing cloud to be a protostar?

would require several million degrees kelvin

It is not a star because it cannot fuse hydrogen into helium (“nuclear fusion”)

Nuclear fusion requires a temperature of 10M degrees kelvin

What is a Protostar?

When gravity begins to pull a cloud of dust and mass together in a nebula—Increasingly hotter as the cloud collapses

what would be required for a collapsing cloud to be a protostar?

would require several million degrees kelvin

It is not a star because it cannot fuse hydrogen into helium (“nuclear fusion”)

Nuclear fusion requires a temperature of 10M degrees kelvin

3 basic parts

protostar, accretion disk, jets of gas

protostar definition

first stage of a star

do all protostars become stars?

no, if they don’t get hot enough in nuclear fusion the “failed” stage becomes a brown dwarf

brown dwarfs

“stars” that failed nuclear fusion, smaller than the earths sun but bigger than jupiter, forever cooling, once they emit all the heat they’re dark balls of cold gas, shines for ~15 million years, sometimes orbital

discovery of protostars

first conceptualized by jap astrophys in 1960s, known for his theoretical modeling on pre-main sequence stars, conducted some of the earliest studies on brown dwarfs, “Hayahi Track” named after him for first theorizing of vertical luminosity temp path of early years

how long is this process?

~10 million years to become star/brown dwarf

process of protostar

form gas cloud, clumps of dust form within, large clump condenses in the core by getting hotter, dust/gas turn into disk shape around core, spins to disk, becomes hot enough to form star or if it doesn’t, turns into brown dwarf