I actually thought that would be when the star starts fusing hydrogen into helium... But apparently there are other stages between those two.
According to Wikipedia, "[The protostar phase] ends when the protostar blows back the infalling gas and is revealed as an optically visible pre-main-sequence star, which later contracts to become a main sequence star."Pre-main sequence means the star is not yet on the main sequence; and that, in turn, basically means that it is not yet fusing hydrogen into helium.
The temperature at which hydrogen fuses is 10,000,000 degrees Kelvin. This is the minimum temperature the core of a proto star has to have to become a true star.
They are called oncogenes.
Matter from nebula that condense make proto star.
In the words of my physics teacher 'Not in your lifetime!' Planets form from a disk of dust and gas when the star is just a proto-star. Planets cannot form after the star has been formed.
The Nearest star after our Sun is Alpha-Centuri. It is at a distance of 4 light years. That is it takes light four years to reach the Earth. In term of miles it is ~ 3.6 x 10^(50) miles. or in numbers: 360.000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000.0 miles.
Well,a proto star is a new star.So whena new star forms the other star is no longer a proto star.
The temperature at which hydrogen fuses is 10,000,000 degrees Kelvin. This is the minimum temperature the core of a proto star has to have to become a true star.
That depends on the mass of the proto-star.
Compression. Whenever anything is compressed, it heats up. In a proto-star, clouds of hydrogen gas are compressed by gravitational attraction, and the compression heats the gas.
A "proto-star".
They are called oncogenes.
Matter from nebula that condense make proto star.
No one. It comes from the Greek - proto - meaning first. So first star - a protostar.
In the words of my physics teacher 'Not in your lifetime!' Planets form from a disk of dust and gas when the star is just a proto-star. Planets cannot form after the star has been formed.
A 'proplid', or a proto-stellar object, often called a proto-star, and some believe (as I do) that 'Herbig-Haro Objects', are newly formed stars. At any rate, a star is a mass of gas in space made hot by nuclear reactions.
A disk of gas ad dust that forms round a proto-star as the star coalesces at the center and from which planets accurate. The related links below give more information.
Our Solar System Formed from the remnants of a star wich went supernovae (at least approx 5 billion years ago) the dust from that star started to condense (due to the passing another star or some other mechanism), spinning counter-clockwise, the pressure at the center of this cloud became great enough to start a process know as nuclear fussion (triple alpha process) creating a proto-star, wich was significantly dimmer and smaller than todays Sol. The remaining dust accreted to from proto-planets (maybe upwards of 100), These proto-Planets smashed into each-other and merged to become the inner planets. As for our gas-giants, they formed from cold gas and dust, beyond what is known as the "Frost Line" due to the required colder temperatures to form Gas Planets.