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A protostar is a very young star that is still gathering mass from its parent molecular cloud. It is the earliest phase in the process of stellar evolution . [ 1 ] For a low-mass star (i.e. that of the Sun or lower), it lasts about 500,000 years. [ 2 ]
The radiation from the protostar and early star has to be observed in infrared astronomy wavelengths, as the extinction caused by the rest of the cloud in which the star is forming is usually too big to allow us to observe it in the visual part of the spectrum. This presents considerable difficulties as the Earth's atmosphere is almost entirely ...
In supercritical filaments, observations have revealed quasi-periodic chains of dense cores with spacing comparable to the filament inner width, and embedded two protostars with gas outflows. [4] A protostar continues to grow by accretion of gas and dust from the molecular cloud, becoming a pre-main-sequence star as it reaches its final mass ...
LRLL 54361 also known as L54361 is thought to be a binary protostar producing strobe-like flashes, located in the constellation Perseus in the star-forming region IC 348 and 950 light-years away. The object may offer insight into a star's early stages of formation, when large masses of gas and dust are falling into a newly forming binary star ...
A star forms by accumulation of material that falls in to a protostar from a circumstellar disk or envelope. Material in the disk is cooler than the surface of the protostar, so it radiates at longer wavelengths of light producing excess infrared emission. As material in the disk is depleted, the infrared excess decreases.
Over about 100,000 years, [9] the competing forces of gravity, gas pressure, magnetic fields, and rotation caused the contracting nebula to flatten into a spinning protoplanetary disc with a diameter of about 200 AU [11] and form a hot, dense protostar (a star in which hydrogen fusion has not yet begun) at the centre. [25]
The presence of a magnetic field causes the eventual ejection and collimation of the matter, forming a bipolar outflow or jet. In both cases, bipolar outflows consist largely of molecular gas. They can travel at tens or possibly even hundreds of kilometers per second, and in the case of young stars extend over a parsec in length.
Pre-stellar cores are the nurseries of new stars, and are an early phase in the formation of low-mass stars, before gravitational collapse produces a central protostar.The spatial distribution of pre-stellar cores shows the history of their formation, and their sensitivity to the physics controlling their creation.