Talk:GJ 1132 b

Latest comment: 4 months ago by SevenSpheres in topic Claimed contradiction

Observations

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Is this the smallest transiting exoplanet discovered through ground-based observations? If so, should it be mentioned here? — Preceding unsigned comment added by 176.46.22.7 (talk) 10:36, 12 November 2015 (UTC)Reply

Hotter than Venus?

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The Article suggests that Gliese 1132 b is hotter than Venus but in reality...

Planet Temperature Notes
Venus 737 K (464 °C; 867 °F) Mean temperature
Gliese 1132 b 500 K (227 °C; 440 °F) Estimated

Soo Venus is hotter than Gliese 1132 b? Or the initial temperature of 500 K was a mistake or original research? I noticed that originally the planetbox had 500 K but in the Article it was 500°F, Which would result in a somewhat similar number 533 K (500 °F (260 °C; 533 K)) Davidbuddy9 (talk) 04:55, 14 November 2015 (UTC)Reply

Well there seems to be a lot of confusion; articles using different measures and different scales, all not very helpful. Unfortunately you have not compared like with like in that table. The Venus figure above is the measured mean surface temperature, which is atmosphere dependant. The Gliese 1132 b figure appears to be an average of the estimated equilibrium temperature. In fact the actual paper [1] (btw why does our article link to the pay-walled version?) gives the range of equilibrium temperature as;
"between 580 K (assuming a Bond albedo of 0) and 410 K (assuming a Venus-like Bond albedo of 0.75)"
The equilibrium temperature of Venus by comparison is a meagre ~260 K, so everything being equal Gliese 1132 b should be hotter. The reason Venus' surface is 500 K hotter than that is the runaway greenhouse effect that traps heat near the surface, see the scale height diagram in Atmosphere_of_Venus#Troposphere. However as the paper notes, due to the high insolation GJ 1132b receives from its star;
"Irradiated well beyond the runaway greenhouse limit, surface water would extend up to high altitudes where it could be destroyed by photolysis and its hydrogen rapidly lost to space."
indicating it would have a similar if not worse greenhouse effect and thus probably an even higher surface temperature than Venus. ChiZeroOne (talk) 13:38, 14 November 2015 (UTC)Reply

Move discussion in progress

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There is a move discussion in progress on Talk:Gliese 1214 b which affects this page. Please participate on that page and not in this talk page section. Thank you. —RMCD bot 18:17, 6 May 2023 (UTC)Reply

Claimed contradiction

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Contradiction between parts of the article. For example, the lead say that the planet may be cool enough to have an atmosphere, but the "atmosphere" section says that it is unlikely.

This isn't a contradiction. Saying that a planet may be cool enough to have an atmosphere doesn't mean it actually does have an atmosphere, and we don't know for sure either way - while claimed detections of an atmosphere have been disputed, not all types of atmosphere have been ruled out either. SevenSpheres (talk) 00:39, 4 July 2024 (UTC)Reply