Rick Johnson wrote:
IC
18 without its tidal arms is only about 35 million light years across, a
small spiral galaxy. With its tidal arms it is almost 220,000 light
years across!

Oops. Let's correct that to read:
IC 18 without its tidal arms is only about 35 THOUSAND light years
across, a small spiral galaxy. With its tidal arms it is almost
220,000 light years across!

Rick

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Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".