1. A planetary nebula has an angular diameter of 76 arc seconds and a distance of 5100 ly. What is its linear diameter (in ly)? Hint: Use the small-angle formula: angular diameter (in arc seconds)2.06 ✕ 105=linear diameterdistance 2. Suppose a planetary nebula is 3.2 pc in diameter, and Doppler shifts in its spectrum show that the planetary nebula is expanding at 31 km/s. How old is the planetary nebula in yr? (Note: 1 pc = 3.1 ✕ 1013 km and 1 yr = 3.2 ✕ 107 s.)

1.Small angle Formula:D=αd2.06×105where, D is the linear diameterα is the angular diameter=76 arc…

1. A planetary nebula has an angular diameter of 76 arc seconds and a distance of 5100 ly. What is its linear diameter (in ly)? Hint: Use the small-angle formula: angular diameter (in arc seconds) 2.06 ✕ 105= linear diameter distance

1. A planetary nebula has an angular diameter of 76 arc seconds and a distance of 5100 ly. What is its linear diameter (in ly)? Hint: Use the small-angle formula: angular diameter (in arc seconds) 2.06 ✕ 105= linear diameter distance

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