SNC1DW Chapter 8

Varying types of electromagnetic waves, from radio waves to gamma rays. All waves travel at the speed of light.

A telescope that uses a lens to collect the light from an object.

A telescope that uses a mirror to collect the light from an object. 

An artificial object/vehicle that orbits a celestial body. Can also be a celestial body that orbits another of a larger size.

E.g. The Moon, The Hubble Space Telescope

Observatories that orbit other planets. Usually made to take high-resolution pictures not obtainable from Earth.

The theory that describes how planets and stars formed from spinning, contracting disks of dust and gas.

A celestial body made of super-heated hydrogen and helium.

A giant cloud of gas and dust, which could be the birthplace of most, if not all, celestial bodies.

The hot, condensed object at the center of a nebula.

The process where hydrogen nuclei fuse to form helium nuclei. This is also a process of energy production.

The Sun's surface layer.

Area of strong magnetic fields on the photosphere.

Streams of fast-moving charged particles released by the Sun into the solar system.

Fast-moving charged particles released from the Sun that collide with Earth's or another celestial body's atmosphere.

• The Sun:
• -is needed for all life on Earth
• -drives most processes on Earth
• -powers the winds and ocean currents
• -provides photosynthesis

The measure of the total amount of energy a star radiates per second. Measured in Joules/second.

E.g. Astronomers have found stars from 10 000 times less luminous than the Sun, to over 30 000 times more luminous.

A star's magnitude as seen 32.6 light-years from Earth.

An instrument that produces a spectrum from a narrow beam of light, and projects it onto a photographic plate/digital detector.

Certain wavelengths in a spectrum identified by lines. Spectral lines identify chemical elements.

A graph that compares the properties of stars.

A band of stars on the H-R diagram that runs diagonally from the top-left to the bottom-right. 90 percent of stars are in the main sequence.

A small, dim, yet very hot star.

A giant explosion where the entire outer parts of a star get blown off.

A star so dense that only neutrons exist in it's core.

Nebula -> small protostar -> red dwarf -> red main sequence star -> white dwarf. Low mass stars stay as main sequence stars for as long as 100 billion years. When they run out of hydrogen, they become white dwarfs.

Nebula -> medium protostar ->  yellow main sequence star -> red giant -> white dwarf. Intermediate-mass stars burn their hydrogen faster than low-mass stars, so they only last about 10 billion years. When their hydrogen runs out, they become red giants and eventually white dwarfs.

Nebula -> large protostar -> blue main sequence star -> red supergiant -> supernova -> neutron star or black hole. High-mass stars burn their hydrogen the fastest, so they die more quickly and violently. Heavier elements form by fusion, and the star expands into a supergiant. When the star explodes during a supernova, it becomes either a neutron star or a black hole.

The result of the deaths of stars over 25 solar masses. The remnants of the supernova is crushed by gravity and nothing can escape it, not even light.