Hill's Space

Brightnesses are cursed

 |  1 min  |  128 words

Today I learned that astronomers measure star brightnesses in the modern AB system, using (logarithmic) units of Janskys, where one Jansky is 10−26 W⋅m−2⋅Hz−1. Why is there the extremely cursed Hz−1? Hz is already s−1. Why is it like that. Astronomers, why is it like that. s−1−1 is just seconds

If you cancel all the units, you get… 1 Jy = 10−26 kg m2 s−3m−2 s−1−1 = 10-26 kg s−2. …so we measure starlight in the same units as surface tension. If you really wanted to, you could talk about how bright a star is by how much its light would stretch a soap bubble.

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