General Astronomy Quiz 13 Flashcards
What does a star’s mass determine?
Everything about a star’s life
What is space made up of?
Clouds of gas and dust (Interstellar Medium)
Is space empty?
NO
What can dust and dark clouds obscure?
Our view of distant objects
Where do stars form?
In dense, molecular clouds
What is nebulae?
The clouds of gas and dust found in the ISM
What is emission nebula?
When clouds of hydrogen are heated, electrons are lost, and atoms are ionized. The heated cloud of gas glows.
What is a famous example of an emission nebula?
Orion’s Nebula
What is a reflection nebula?
A cloud of interstellar gas and dust that shines by reflecting light from nearby stars, it does not make light on its own.
Do clouds of dust scatter red and blue photons differently?
YES
What is interstellar reddening?
When starlight appears redder than it is due to the scattering and absorption of shorter wavelengths of light (blue) by interstellar dust.
What is a dark nebula?
A dense cloud of solid grains of material.
Does dark nebula look dark in visible light?
YES
What does infrared wavelengths allow you to do?
See through clouds
What is dust better at doing?
Blocking or scattering shorter wavelengths
What is a giant molecular cloud?
Large region of gas and dust, primarily composed of molecular hydrogen
Where are many new stars hidden?
Stellar nursery
What do stars tend to form in?
Star clusters
What forms a protostar/protostellar disk?
When a shock wave travels through a GMC and collapses smaller, denser regions
When does hydrogen fusion turn on?
When a protostar contracts and the core gets very hot
What do ALL main sequence stars do?
Turn FOUR hydrogen atoms into ONE helium atom through fusion
What does the Sun and low mass stars use?
Proton-proton chain
What is the proton-proton chain?
A series of nuclear fusion reactions that converts hydrogen into helium
What process do stars with higher masses use?
The Carbon-Nitrogen cycle (CNO)
