Core astrophysics concepts such as redshift, light-years, stellar classification, and gravitational lensing explained in plain language. Front: the concept. Back: a plain-language explanation.
36 cards · basic cards · AI-written, checked twice. Edit anything.
- Redshift
Show answer
The shift of light toward the red end of the spectrum when an object moves away from us, caused by the Doppler effect.- Blueshift
Show answer
The shift of light toward the blue end of the spectrum when an object moves toward us, caused by the Doppler effect.- Light-year
Show answer
The distance light travels through empty space in one year, equal to about 5.88 trillion miles or 9.46 trillion kilometers.- Parallax
Show answer
The apparent shift in position of a nearby star when viewed from opposite sides of Earth's orbit around the Sun, used to measure stellar distances.- Apparent magnitude
Show answer
How bright a star appears from Earth, as measured by the naked eye or telescopes.- Absolute magnitude
Show answer
The intrinsic brightness of a star if it were placed at a standard distance of 10 parsecs (32.6 light-years) from Earth.- Luminosity
Show answer
The total amount of energy a star radiates per unit time, measured in watts.- Hertzsprung-Russell diagram
Show answer
A scatter plot of stars showing the relationship between their luminosity and surface temperature, revealing stellar properties and life stages.- Spectral classification
Show answer
A system categorizing stars by their surface temperature and spectrum using letters O, B, A, F, G, K, M, from hottest to coolest.- Main sequence
Show answer
The long-lived phase of a star's life when it fuses hydrogen in its core, represented as a diagonal band on the Hertzsprung-Russell diagram.- White dwarf
Show answer
A dense remnant of a star after it has shed its outer layers, about the size of Earth but with the mass of the Sun, slowly cooling over time.- Red giant
Show answer
A large, cool, reddish star in the late stage of stellar evolution, formed when a star exhausts hydrogen fuel and expands.- Neutron star
Show answer
An extremely dense stellar remnant composed almost entirely of neutrons, typically 20 kilometers in diameter but with the mass of the Sun.- Black hole
Show answer
A region of spacetime where gravity is so extreme that not even light can escape from beyond the event horizon.- Event horizon
Show answer
The boundary around a black hole from which no object or light can escape, even at the speed of light.
FlashKeepers