Question

Scientists using the Hubble Space Telescope have observed Cepheids in the galaxy M 100. Here are the actual data for three Cepheids in M 100:
Cepheid 1: luminosity = 3.9×1030 watts, brightness 9.3×10−19watt/m2
Cepheid 2: luminosity = 1.2×1030 watts, brightness 3.8×10−19watt/m2
Cepheid 3: luminosity = 2.5×1030 watts, brightness 8.7×10−19watt/m2

Compute the distance to M 100 with data from each of the three Cepheids.

Express your answers using two significant figures. Enter your answers numerically separated by commas.

Answer 1

The relation belween the lumingsity CL) and brightness (8) is iven by Where distance to the star d is the 4B 30 Watts ce Pheid L 3.5x10 For 3 x 1019 Wa 3.9x 1030 4*x.3X10 22 5.77 x10 m 3. 086 x16 Parsec Nouw Pe 18. 72 x10 A 18.42 MP Pe 1.8 x 10 1.9 x 10Pe Cant upto two iaures

cepheid 2, L For 30 l2x 10 3.8 x 10 61- 4/M 1-2え1030 m 4xx 3.8X1D19 23 5.01 X10 |d2 1.6 X l0 30 W 2.5x10 For cepheid 3 w/m2 8.7LO 30 25 X10 A x 8.7X1 9 2. 3 Ym 4.18 X10 da ニ 1, 5 X1o