Various - chaos core i and ii

In the dense nebulae where stars are produced, much of the hydrogen is in the molecular (H 2 ) form, so these nebulae are called molecular clouds . [3] Observations indicate that the coldest clouds tend to form low-mass stars, observed first in the infrared inside the clouds, then in visible light at their surface when the clouds dissipate, while giant molecular clouds, which are generally warmer, produce stars of all masses. [5] These giant molecular clouds have typical densities of 100 particles per cm 3 , diameters of 100 light-years ( × 10 14   km ), masses of up to 6 million solar masses ( M ☉ ), [6] and an average interior temperature of 10  K . About half the total mass of the galactic ISM is found in molecular clouds [7] and in the Milky Way there are an estimated 6,000 molecular clouds, each with more than 100,000  M ☉ . [8] The nearest nebula to the Sun where massive stars are being formed is the Orion nebula , 1,300 ly ( × 10 16  km) away. [9] However, lower mass star formation is occurring about 400–450 light years distant in the ρ Ophiuchi cloud complex . [10]

Various - Chaos Core I and IIVarious - Chaos Core I and IIVarious - Chaos Core I and IIVarious - Chaos Core I and II