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Pre-solar nebula forms and begins to collapse. Sun begins to form. [38] 100,000 – 50 million years 4.6 bya: Sun is a T Tauri protostar. [9] 100,000 – 10 million years 4.6 bya: By 10 million years, gas in the protoplanetary disc has been blown away, and outer planet formation is likely complete. [38] 10 million – 100 million years 4.5–4. ...
A protoplanetary nebula or preplanetary nebula [1] (PPN, plural PPNe) is an astronomical object which is at the short-lived episode during a star's rapid evolution between the late asymptotic giant branch (LAGB) phase and the subsequent planetary nebula (PN) phase. A PPN emits strongly in infrared radiation, and is a kind of reflection nebula.
The widely accepted modern variant of the nebular theory is the solar nebular disk model (SNDM) or solar nebular model. [1] It offered explanations for a variety of properties of the Solar System, including the nearly circular and coplanar orbits of the planets, and their motion in the same direction as the Sun's rotation.
These objects represent the final stage before a planetary nebula. During this stage, the red giant star begins to slowly expel its outermost layers of material. A protoplanetary nebula usually glows by reflecting the light from its parent star. This stage is usually brief, typically lasting no more than a few thousand years.
Presolar grains are individual solid grains which condensed around distant stars or as part of novae, and potentially supernovae outflows, which were accreted in the early solar nebula and remain in relatively unaltered chondritic meteorites. As they were accreted before the formation of the Solar System, they must be presolar.
Box Nebula NGC 6445: 1786 4.5 11.2 Sagittarius: Eye of Sauron Nebula M 1-42: 10 14 Sagittarius
HBC 1 is a young pre-main-sequence star. [11] Regardless of the details, the outer surface of a protostar consists at least partially of shocked gas that has fallen from the inner edge of the disk. The surface is thus very different from the relatively quiescent photosphere of a pre-main sequence or main-sequence star. Within its deep interior ...
The Westbrook Nebula, a protoplanetary nebula. A protoplanetary nebula or preplanetary nebula [27] (PPN, plural PPNe) is an astronomical object which is at the short-lived episode during a star's rapid evolution between the late asymptotic giant branch (LAGB) phase and the subsequent planetary nebula (PN) phase.