Star Formation

What condition is considered sufficient for an interstellar cloud to collapse andform a star or stars (i.e., if this condition holds then the cloud has to collapse)?

Gravity must dominate gas pressure inside the cloud.
The smallest mass that a main sequence star can have is about 0.08 solar mass.The reason for this is that

the temperature in the core of a contracting protostar of less than 0.08 solarmasses does not get high enough for nuclear reactions to start.
Which kind of nebula is heated by hot, young massive stars?

Emission
The most likely places in which stars and planetary systems are forming in theuniverse are

gas and dust nebulae.
Protostars are objects

that are slowly contracting and heating up.
Dark Nebulae

Raw material for star and planet formation
Protostars

collapsing clumps of gas on their way to becoming stars, which have not started nuclear fusion. Protostars are large cool and luminous.
At what temperature does nuclear fusion start?

10 million K.
What is the interstellar medium

the matter that exists in the space between the star systems in a galaxy. The space is not completely empty, contains huge clouds of gas and dust called nebulae.
Dark nebulae are also known as?

molecular clouds
Emission Nebulae
- Clouds of ionized gas surrounding hot, massive,
- newborn stars.

Author

Kencollins08

150740

Card Set

Star Formation

Description

star formation

Updated

2012-04-28T20:58:03Z

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