5511 Deck 15 Extra Cards Flashcards
Define:
Active galactic nuclei
(AGN)
Extremely luminous centers around supermassive black holes.
They are found in some galaxies and emit high amounts of energy.
List and describe:
irregular galaxies
- Irregular I galaxies lack a distinct shape but still have some structure.
- Irregular II galaxies lack any kind of structure.
These classifications are based on the degree of organization.
Describe:
shell galaxies
Their stars are arranged into shells or layers.
They may have formed from two galaxies oscillating in orbit while merging.
Identify:
How many planets are in the solar system?
Eight
Pluto was demoted to a dwarf planet in 2006.
Identify:
Another term for Jovian planets.
Gas giants
They do not have a solid surface and are primarily composed of gases.
Identify:
The closest star to Earth.
The Sun
Sirius is one of the brightest stars visible from Earth.
Identify:
What defines an average star?
Stars with masses between 0.5 and 8 solar masses.
These are also known as intermediate-mass stars.
Define:
A protostar cloud
A dense region of gas that begins to heat up as it collapses and forms a star.
It eventually reaches temperatures high enough for hydrogen fusion.
Explain:
Hydrostatic equilibrium in the context of star formation.
The balance between thermal pressure and gravitational collapse in a star’s core.
This occurs as the core temperature rises.
Explain:
What occurs during the red giant phase of an average star?
The star expands as hydrogen fusion moves away from the core into shells.
The core shrinks under gravitational contraction during this phase.
Describe:
The fate of a high-mass star after a supernova.
It may become a neutron star or a black hole, depending on the mass of the remaining core.
A core less than 2 solar masses becomes a neutron star; larger forms a black hole.
Explain:
The difference between a massive star and an average star.
Massive stars have shorter lives and end up as neutron stars or black holes, while average stars end as white dwarfs.
Average stars include those with masses between 0.5 and 8 solar masses.
Identify:
How long can a star’s lifespan range based on its mass?
From a few million years for massive stars to trillions of years for less massive stars.
Lifespan is inversely related to mass.
Identify:
The person who discovered the first asteroid and the year of its discovery.
List:
The three types of asteroids based on composition.
- C-type (chondrite)
- S-type (stony)
- M-type (metallic)
C-type asteroids are dark, S-type are somewhat bright, and M-type can have volcanic lava.
Explain:
What happens to meteors when they enter the Earth’s atmosphere?
They burn up and produce a fireball.
Meteors are commonly referred to as shooting stars.
Identify:
What are comets primarily made of?
Dust, rocks and ice.
Comets release gases when they warm up near the sun.
Explain:
The difference between asteroids and comets.
- Asteroids: primarily made of rock and metal.
- Comets: composed of rock, ice and dust.
Asteroids are found in the asteroid belt, while comets originate from the Oort Cloud and Kuiper Belt.
Explain:
What causes meteors to appear during meteor showers?
Earth passing through debris left by comets.
This debris burns up in the atmosphere, creating visible meteors.
Identify:
The organization that established the classification system for dwarf planets.
The International Astronomical Union
(IAU)
This was established in 2006.
This classification included planets, dwarf planets and asteroids.
List:
The five recognized dwarf planets in our solar system.
- Ceres
- Pluto
- Haumea
- Makemake
- Eris
The order is based on their position relative to the Sun.
Identify:
The radius of Haumea.
Around 385 miles (620 km).
Named after the Hawaiian goddess of fertility, Haumea is located in the Kuiper belt.
Identify:
The mass of Eris.
16,600,000,000,000,000,000,000 kg.
It is the most massive of all known dwarf planets.
