Comments on: clouds

By: systemic - Roboscope

systemic - Roboscope — Wed, 26 Apr 2006 16:16:10 +0000

[...] Like Marlon Brando in On the Waterfront, GL 581 b “could’ve been a contender”, and connoisseurs of the might-have-been should be sure to read the oklo posts [1,2] that talk about what this planet would have taught us if only it was transiting… [...]

By: systemic - GL 581. Flat, unfortunately.

systemic - GL 581. Flat, unfortunately. — Mon, 17 Apr 2006 23:23:37 +0000

[...] For more details on the GL 581 campaign, please read (1) this oklo post, “clouds”, and then (2) this oklo post, “two for the show”. For information on how amateur astronomers and small-telescope observers can participate in the search for transiting extrasolar planets, see our website for transitsearch.org. Over the coming months, we’ll be integrating transitsearch.org much more tightly into the oklo site. The systemic project and the transitsearch project both have a common goal of facilitating meaningful public participation in cutting-edge extrasolar planet research. [...]

By: systemic - two for the show

systemic - two for the show — Sun, 02 Apr 2006 22:51:34 +0000

[...] As dicussed in previous posts, GL 581 “b” has a minimum mass of 17.8 times the Earth’s Mass (very close to the mass of Neptune), and orbits with a 5.366 day period around a nearby red-dwarf star. The a-priori geometric probability that GL 581 b can be observed in transit is 3.6%. Because the orbit of the planet has been well-characterized with the radial velocity technique, we can make good predictions of the times that transits will occur if the plane of the planet’s orbit is in close enough alignment with the line of sight to the Earth. The star can then be monitored photometrically during the transit windows to look for a telltale dimming lasting a bit more than an hour as the planet crosses the face of the star. [...]

By: systemic - A Case for Habitable Planets Orbiting Red Dwarfs

systemic - A Case for Habitable Planets Orbiting Red Dwarfs — Thu, 30 Mar 2006 01:42:38 +0000

[...] We’ve completed three sets of calculations, and our computers are currently working on a large number of additional runs. In the first set (containing sixty individual simulations) we assume that two Neptune-like giant planet cores have already managed to form beyond the protostellar ice line (where the temperature is lower than 150K, and where planets can grow more quickly because of the availability of ices), and we assume that the innermost Neptune-mass core has been able to migrate a small ways inward to a distance of ~0.2 AU from the central star. This situation was chosen so as to be in analogy with the known Neptune-mass planets orbiting the red dwarfs GL 436 and GL 581 (see yesterday’s post). In a second set of sixty simulations, we didn’t include the giant planet cores. In our simulations, the Neptune-mass cores assume a role similar to that which Jupiter and Saturn are believed to have had during the formation phases of the terrestrial planets in our own solar system. [...]