Early next week I’ll be discussing the winning entry in Project Hyperion’s design contest to build a generation ship. But I want to sneak in the just announced planet candidate at Alpha Centauri A today, a good fit with the Hyperion work given that the winning entry at Hyperion is designed around a crewed expedition to nearby Proxima Centauri. Any news we get about this triple star system rises immediately to the top, given that it’s almost certainly going to be the first destination to which we dispatch instrumented unmanned probes. And one day, perhaps, manned ships, if designs like Hyperion’s ‘Chrysalis’ come to fruition. More on that soon, but for today, be aware that the James Webb Space Telescope is now giving us evidence for a gas giant orbiting Centauri A, the G-class star intriguingly similar to the Sun, which is part of the close binary that includes Centauri B, both orbited by the far more distant Proxima. Image: This artist’s concept shows what the gas giant orbiting...

Science fiction has always provoked interesting research. After all, many of the scientists I’ve spoken with over the years have been science fiction readers, some of whom trace their career choices to specific novels (Poul Anderson’s Tau Zero is frequently mentioned, but so is Frank Herbert’s Dune, and there are many others). This makes sense because there is a natural tension in exoplanet studies growing out of the fact that in most cases, we can’t even see our targets. Instead, we detect them through non-visual methods. True, we can analyze planetary atmospheres for some gas giant planets, but we’re only beginning to drill down to the kind of biosignature searches that may eventually flag the presence of life. But fiction can paint a planet’s physics and visually explore its surface, modeling worlds in vast variety and sometimes spurring directions of thought that would otherwise remain unexplored. Consider Hal Clement, whose forays into planet-building included the remarkable...

We have so few exoplanets that can actually be seen rather than inferred through other data that the recent news concerning the star TWA 7 resonates. The James Webb Space Telescope provided the data on a gap in one of the rings found around this star, with the debris disk itself imaged by the European Southern Observatory’s Very Large Telescope as per the image below. The putative planet is the size of Saturn, but that would make it the planet with the smallest mass ever observed through direct imaging. Image: Astronomers using the NASA/ESA/CSA James Webb Space Telescope have captured compelling evidence of a planet with a mass similar to Saturn orbiting the young nearby star TWA 7. If confirmed, this would represent Webb’s first direct image discovery of a planet, and the lightest planet ever seen with this technique. Credit: © JWST/ESO/Lagrange. Adding further interest to this system is that TWA 7 is an M-dwarf, one whose pole-on dust ring was discovered in 2016, so we may have an...

The assumption that gas giant planets are unlikely around red dwarf stars is reasonable enough. A star perhaps 20 percent the mass of the Sun should have a smaller protoplanetary disk, meaning sufficient gas and dust to build a Jupiter-class world are lacking. The core accretion model (a gradual accumulation of material from the disk) is severely challenged. Moreover, these small stars are active in their extended youth, sending out frequent flares and strong stellar winds that should dissipate such a disk quickly. Gravitational instabilities within the disk are one possible alternative. Planet formation around such a star must be swift indeed, which accounts for estimates as low as 1 percent of such stars having a gas giant in the system. Exceptions like GJ 3512 b, discovered in 2019, do occur, and each is valuable. Here we have a giant planet, discovered through radial velocity methods, orbiting a star a scant 12 percent of the Sun’s mass. Or consider the star GJ 876, which has two...