APOD: TrES 2b: Dark Planet (2011 Aug 22)

[ruprecht147]

I'm glad to see that at least a few commenters were bugged by the inclusion of the phony exomoons. A few studies have argued very cogently that Hot Jupiters won't have any satellites; see Namouni 2010, ApJ Letters [http://adsabs.harvard.edu/abs/2010ApJ...719L.145N] and Barnes & O'Brien 2002, ApJ [http://adsabs.harvard.edu/abs/2002ApJ...575.1087B].

[DavidLeodis]

The APOD is a slightly cropped version of the full artistic illustration that is brought up through the "shown above" link (or clicking on the APOD) with the result that the APOD has particularly cut off much of the solar flare at the top right. It seems an unnecessary thing to me to have made a cropped version as the full one would not have been much larger and to me is a better version.

[neufer]

It seems to me something rather misleading about the sketch is that the planet is shown as being on this side of its star. But on this side of its star, with the star as a backdrop, surely any planet would look darker than this one. Where the darkness must really be evident is when it's on the far side, almost behind the star. I presume that's where the darkness must have stood out in the data as compared to other planets which would be bright (though dim compared to the star of course), then that brightness would disappear from the total incoming light, then reappear as the planet finished passing behind the star and came back into view.

The darkness of the planet is represented artistically by a distinctive but very faint crescent.

If the planet was instead drawn close to full phase (i.e., near to superior conjunction) as you have suggested then it would be rather hard for one to distinguish between the reflected light and the natural glow of the warm planet.

[sato]

i know that at least one star - BPM 37093 - has been found to have a core of crystallized carbon (diamond), and i also know that carbon nanotubes are being developed as a surface for solar panels due to their extremely low reflective properties. these 2 ideas lead me to a theory.... perhaps this is not a planet but a dead companion star, with its body (or possibly just a core, the outer layers having been blown off or otherwise removed) consisting not of diamond, but another kind of very non-reflective carbon structure?