Answer Happy

Please answer case 4, 5, 6
CASE 4: Draw a light curve for the following conditions: (fourth case): (1) two stars of equal surface brightness (2) no limb darkening (3) alternately total and annular eclipses (4) elliptical orbit with a major axis not lined up with the observer's line of sight. DRAW IN AT LEAST FOUR MINIMA. Exaggerate all important characteristics. The sides of the minima MUST slope in. They should come down, and go up, at an angle, left to right. Do your practice sketch here. Draw your final work on page 11 using a ruler and measuring carefully. LIGHT CURVE 4 LIGHT INTENSITY CASE 5: Now we will vary condition 1. Consider two stars which differ in surface brightness (brightness per unit area). Suppose we have a small star of high surface brightness, and a large star of low surface brightness, e.g. a white dwarf and a red giant. When the small star is in front of the large star, each square inch of the large star that is blocked is replaced by a square inch. of the small star that sends us more light than the covered area of the big star alone, but less than that sent by both stars together. When the small star is eclipsed by the large star, the minima will be deeper than the other minima because the relatively bright area of the small star is covered by a relatively dim area of the large star. The total time from start to end of each. eclipse is the same in both cases, however. Conditions for the fifth case: (1) Stars with different surface brightness (2) no limb darkening (3) alternately total and annular eclipses. (4) aligned elliptical orbit. LIGHT CURVE 5 LIGHT INTENSITY LIGHT CURVE 6 LIGHT INTENSITY CASE 6: Draw a light curve for the following conditions (sixth case): (1) a small star of high surface brightness and a large star of low surface brightness (2) no limb darkening (3) partial eclipses (Sides of graph MUST slope in.) (4) circular orbits. Do your practice sketch here. Draw your final work on page 11 using a ruler and measuring carefully. TIME 5 Partial eclipse without limb darkening. TIME Partial eclipse with limb darkening. TIME When we studied the Sun we learned that the term limb darkening means the Sun is darker around the edges than at the center. The same effect is encountered in stars other than our Sun. Thus less light is lost from covering the edges of the star than from covering the middle. The result is a gradual curve into the eclipse rather than sharp corners. The shape of the curve would change as shown. 5/12 Note that the top comers are curved, but the minimum is still a point.