granthutchison wrote:OK, I installed it and tried for myself (couldn't resist ...
![Wink :wink:](./images/smilies/icon_wink.gif)
) My calcs above give an eclipse duration of 1.0241 days, and my best eyeball at extracting first and last contact from Celestia comes out at 1.0246 days. The error falls below the limits of my screen resolution, so I doubt if I'm going to get a better match!
Yeah, I checked and got 1.0228 days, which is in the right ballpark - I didn't bother zooming
right in, but that's close enough I think
![Smile :)](./images/smilies/icon_smile.gif)
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granthutchison wrote:I'm not seeing this. Total luminosity 3.4 at ~2.55AU, right?
Gah! I multiplied by the luminosity twice, that's why my answers were wrong! Well spotted
![Embarassed :oops:](./images/smilies/icon_redface.gif)
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During eclipse you've got 1.7 suns at 2AU, which is
T = 278.3 * 1.7^0.25/2^0.5 = 225K
This I agree with, now I've corrected my spreadsheet!
![Smile :)](./images/smilies/icon_smile.gif)
Using an equation I know you've used previously, that's a blackbody temperature of:
T = 278.3 * 3.4^0.25/2.55^0.5 = 237K
And I also get this now, though I did it by adding the 'flux' from both stars and then taking the fourth root of the total, like you said on
this thread here. But the answer's the same.
It was a silly mistake in my spreadsheet, my excuse is that it was late last night when I wrote it
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You'll also find that insolation is maximal either side of eclipse, and falls to a minimum when the two stars are at their most widely separated, in the 90-degree position.
I told you I was a dunce when it came to binaries
![Smile :)](./images/smilies/icon_smile.gif)
. That's odd, but I see how it works like that now you've explained it... I'd just assumed that at the 90 degree position you'd get two stars equally apart, whereas near the eclipse you'd get one star a lot further away than the other, which would be less insolation than at the 90 degree position. Evidently I was mistaken there!
Though this wouldn't necessarily be true if the luminosities of the stars were different, would it?
Hmmm. Might be worth coming up with an equation for the duration of maximal eclipse - from second contact to third contact, which is the only time the insolation is really this low.
The further star is completely occulted by the nearer star for very close to 5 hours, according to Celestia. Quite a long time, compared to our own solar eclipses!
Oh yeah, turn the orbits on, move the viewpoint above the system so you can see a plan view of all the orbits (including the planet's), Track and Lock onto Star1, and speed up the simulation to see how the planet moves around the binary in the reference frame of Star1
![Smile :)](./images/smilies/icon_smile.gif)
. I wish there was some way to view the orbital tracks around the point you've locked onto, that'd make a nice simulation of the planet's motion in a rotating reference frame.