Astronomy Ch.8 (The family of stars) Crossword
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Down:
2) a star system in which the stars are too close together to be visible separately. we see a single point of light. only in a spectrum can the two stars be detected 4) a graph of brightness versus time commonly used in analyzing variable stars and eclipsing binaries 5) the arrangement of spectral classes (OBAFGKM) ranging from hot to cool7) pairs of stars that orbit around their common center of mass8) a main-sequence star cooler than an M star10) a measure of the flow of energy through a surface. usually applied to light 14) a very cool, low-mass star or brown dwarf located below the L stars on the main sequence 15) the distance to a hypothetical star whose parallax is 1 second of arc. 1 PC = 206,265 AU = 3.26 ly16) a group of stars that formed together and orbit a common center of mass 17) exceptionally luminous star whose diameter is 10 to 1000 times that of the sun 23) large, cool, highly luminous star in the upper right of the HR diagram. typically 10 to 100 times the diameter of the sun |
Across:
1) the more massive a star is, the more luminous it is 3) intrinsic brightness of a star. the apparent visual magnitude the star would have if it were 10 pc away6) the method of determining a star's distance by comparing its apparent magnitude with its absolute magnitude as estimated from its spectrum 9) a plot of the intrinsic brightness versus the surface temperature of stars. it separates the effects of temperature and surface area on stellar luminosity and is commonly plotted as absolute magnitude versus spectral type but also as luminosity versus surface temperature or color 11) a measure of stellar distance12) a star whose mass is too low to ignite nuclear fusion and that is heated by contraction 13) the mathematical formula that relates the apparent magnitude and absolute magnitude of a star to its distance 18) a faint, cool, low-mass, main-sequence star 19) a binary star system in which the stars eclipse each other 20) a category of stars of similar luminosity, determined by the widths of lines in their spectra 21) a star's position in the temperature classification system, O, B, A, F, G, K, M, based on the appearance of the star's spectrum 22) the region of the HR diagram running from upper left to lower right, which includes roughly 90% of all stars 24) the total amount of energy a star radiates in 1 second25) a binary star system in which the two stars are separately visible in the telescope 26) the true brighness of an object independent of its distance. also referred to as "luminosity" 27) dying star at the lower left of the HR diagram that has collapsed to the size of Earth and is slowly cooling off |
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