Homework : Measuring stellar brightnesses and stellar colors with virtual simulators - Assignment Example

Part Minimum exposure time required to see the star utilizing the eye with virtual detector Case 80 seconds Case 2= 20 secondsCase 3= 20 secondsCase 4= 20 secondsMinimum exposure time for the difference amidst the numbers in the green box and red box approximated within the range 50 – 100= 80-20= 60 secondsPart 21. Wavelength of the peak emission when temperature is at 8000 λ1= 2.9* 106/ 8000 = 362.5nm2. Wavelength of the peak emission when the temperature 4000λ2= 2.9* 106/ 4000 = 725nm3.

Ratio of the two wavelengthsRatio= λ2/ λ1 = 725/ 362.5 = 2The ratio is genuine since a temperature of 4000k possesses twice-longer wavelength than 8000k4. Color of the star at 7000kA white star possess a temperature of approximately 7000k5. Color of star at temperature of 4500kAn orange star a surface temperature of 45006. Temperature that produces a B-V value of 0.5B-V = -3.684 log (T) + 14.551 B-V = 0.344 [log (T)]2 -3.402 log (T) +8.037 For the log (T) >3.961 Temperature= 6517.196 °K7. Percentage in Temperature B-V value of 0.5= 6517.196°KB-V value of 0.6= 0.6/0.5*6517.196 °K = 7820.

6352 °KPercentage change in temperature= (7820.6352-6517.196)/ 6517.196 8 100% = 20%Thus, 20% change in temperature produces 10% change in B-V8.Thus, 20% change in temperature produces 10% change in B-V9. As the star becomes cooler and red, the B-V color index escalates since lesser magnitudes designates brighter light. Hot stars possess a small B-V whilst cool starts possess a bigger B-V. This makes B-V to lose temperature sensitivity for the underlying hot stars.

Moreover, hot starts radiate blue and corresponding ultra-violet wavelengths. 10. Exterior temperature of the underlying star is determined precisely by assessing the prevailing colors of the light it emits. Observation of the spectrum discloses the existing temperature of the prevailing stars’ surface (Seeds & Dana, 135-189). Careful observation at the stars within the sky depicts that the sky is compose of diverse colour mostly white, blue and red. A spectrum starts from ultra violet via the visible wavelengths and via infrared (Chromey, 232-278).

Nevertheless, the general shape of the spectrum is the identical to the hot objects, hotter objects that radiate relatively more energy mainly directed to the blue and underlying ultra violet end of the existing spectrum. Works CitedSeeds, Michael A, & Dana E. Backman. Astronomy: The Solar System and Beyond. Belmont, CA: Brooks/Cole, Cengage Learning, 2010. Print.Chromey, Frederick R. To Measure the Sky: An Introduction to Observational Astronomy. Cambridge: Cambridge University Press, 2010. Print.