Ch 4 - Vocabulary Flashcards
What do we call the study of the stars, planets, and all other heavenly bodies?
Astronomy
What do we call scientists who study outer space?
astronomers
What do we call an area containing no air or any other matter?
a vacuum
What do we call the force that resists motion?
friction
What do we call a star system containing from millions to billions of stars?
a galaxy
What do we call the cluster of about 40 galaxies that the Milky Way belongs to?
the Local Group
What do we call a spiral galaxy in which the spiral arms are attached to a straight “bar” that runs though the centre of the galaxy?
a barred spiral
What do we call large clouds of gas and space dust?
nebulae
What do we call a group of stars which seems to outline the shape of a person, an animal, or something else?
a constellation
What do we call the imaginary line around which the earth rotates that stretches from pole to pole through the interior of the earth?
the axis of rotation
What do we call the central, hotest region of the sun?
the core
What do we call the sun’s visible surface (the sphere of light)?
the photosphere
What do we call the darker spots or blotches on the sun’s surface that slowly move across the surface as the sun rotates?
sunspots
What do we call the event that occurs when the earth’s moon passes between the sun and the earth, temporarily blocking the sun’s rays?
a solar eclipse
What do we call the part of the sun’s atmosphere closest to the sun’s surface?
the sphere of colour that is delicate pink or orange
the chromosphere
What do we call the haze of very hot gases that extends hundreds of thousands of miles from the surface of the sun?
the hottest region of the sun’s atmosphere
the corona
What do we call a stream of high-speed particles that escape from the corona?
solar wind
What do we call the distance light travels in one year?
equal to about 9.5 trillion kilometres or 5.9 trillion miles
a light year
What do we call it when a star suddenly flares up to many times its original brightness?
a nova
What do we call the violent explosion of a star?
a supernova
What do we call huge loops of cooler gas erupting thousands of miles from the chromosphere tha are suspended in space by the sun’s magnetic field?
prominences
What do we call a group of two stars that circle around each other?
a binary star
Which word do astronomers use to refer to a star’s brightness?
magnitude
