Amateur astronomers discover a planet with four suns

Re:Amateur astronomers discover a planet with four suns by pdonis on Monday October 15, 2012 @06:45PM (#4657504)

> I'm guessing those stars at 1000AU can't be much brighter than our full moon is

They may well be fainter. According to Wikipedia, the Sun is about 400,000 times as bright as the full moon, on average:

http://en.wikipedia.org/wiki/Apparent_magnitude

So if the Sun were 1,000 AU away from us instead of 1 AU, it would be a million times fainter (1,000 squared), or less bright than the full moon.

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Re:Amateur astronomers discover a planet with four suns by SoftwareMaven on Monday October 15, 2012 @08:15PM (#4657781)

But there are two of them, so that would mean closer to the moon's brightness, right? If I'm following, the sun would be about 40% as bright ast he full moon at 1000AU, so with the second start being smaller than, it may be 60%?

(Mock my math if need be, I'm not really trying here. :)

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Re:Amateur astronomers discover a planet with four suns by pdonis on Monday October 15, 2012 @11:38PM (#4658357)

Yes, the second star would add to the brightness and make things closer. Also, I didn't see in the article what the actual brightnesses of the two stars 1,000 AU away are relative to the brightness of the Sun. I just used the Sun because it was easy to look up the relative brightness of the Sun vs. the Moon. :-)

Edit: I see from looking at more recent posts that the two distant stars are thought to be spectral class G and M. The Sun is a G, so it should be about the same brightness as the brighter of the two.

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