Foundational astronomy vocabulary including orbits, parallax, redshift, and light-years.
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- What is a light-year?
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A unit of distance equal to how far light travels in one year in vacuum- Define parallax
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The apparent shift in position of a nearby object against distant background when viewed from two different locations- What is redshift?
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A shift in light from an object toward longer wavelengths, usually indicating the object is moving away- What is blueshift?
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A shift in light from an object toward shorter wavelengths, usually indicating the object is moving toward us- Define orbit
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The curved path followed by an object around another object under the influence of gravity- What is eccentricity?
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A measure of how elliptical an orbit is, ranging from 0 (circular) to 1 (parabolic)- Define escape velocity
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The minimum speed an object must reach to break free from gravitational attraction without further propulsion- What is luminosity?
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The total amount of energy radiated by a star per unit time in all directions- What is apparent magnitude?
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The brightness of a star as observed from Earth- What is absolute magnitude?
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The intrinsic brightness a star would have if placed at a standard distance of 10 parsecs- Explain parallax angle
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The angle at which a nearby star appears to shift against the background of distant stars as Earth orbits the Sun- What is an AU?
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Astronomical Unit, the average distance from Earth to the Sun, approximately 150 million kilometers- What is a solar mass?
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The mass of the Sun, used as a standard unit to express the mass of other stars- Define photosphere
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The visible surface layer of the Sun from which light is emitted- What is the chromosphere?
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A thin layer of the Sun's atmosphere above the photosphere, visible during a total solar eclipse
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