I can only wonder what Miguel de Cervantes Saavedra would have thought of the idea that a distant star would one day be named for him. I wonder, too, what the Spanish novelist (1547-1616) would have made of the idea that planets circled other stars, and that planets around the star named for him would have names taken from his most famous work, Don Quixote. Maybe the great character of the book's title, obsessed with tales of chivalry, would have been unhinged enough to take things like other solar systems in stride. We have the NameExoWorlds contest to thank for these speculations. The contest, organized by the International Astronomical Union (IAU) gave the public the opportunity to choose the names of selected stars and planets. The star named for Cervantes is mu Arae (HD 160691), a G-class star about fifty light years out in the constellation Ara (the Altar). Here we've found three gas giant planets comparable to Jupiter as well as a 'super-Earth.' And frankly, as a reader who...

Planets that transit across their star as seen from Earth allow us to use transmission spectroscopy to study their atmospheres. The idea is straightforward: Even though we can't see the planet at optical wavelengths, we can examine the starlight that travels through its outer atmosphere during the transit. Each atmosphere leaves its own signature, and the atmospheres of some of the 'hot Jupiters' thus far studied have raised questions. Why do some of these worlds have less water than our models of their atmospheres would predict? Is this an indication that such planets formed in protoplanetary disks that were depleted of water? A new study brings us some answers by going to work on eight hot Jupiters (WASP-6b, WASP-12b, WASP-17b, WASP-19b, WASP-31b, WASP-39b, HAT-P-1b and HAT-P-12b) using the Hubble Space Telescope. The worlds chosen here offer a wide range of temperature, surface gravity, mass and radii. All eight were observed at optical wavelengths using Hubble's Space Telescope...

If you were trying to identify the kind of star that should produce Earth-like planets, you’d think the task would be straightforward. Our theories of planet formation focus on a circumstellar disk around a young star out of which planets form, and we’ve already gathered evidence that gas giant worlds are more likely to form around stars that are rich in iron. Since rocky planets are rich in iron and silicon, doesn’t this mean their stars should be rich in metallic elements? New work out of the Carnegie Institution for Science suggests that the answer is surprisingly complex. As presented by Johanna Teske at the Extreme Solar Systems III meeting in Hawaii, the team’s work has revealed that smaller planets do not require high iron content in their parent stars. In fact, looking at the abundance of 19 different elements in seven stars orbited by at least one rocky planet (these are drawn from the Kepler catalog), the team finds that rocky worlds do not preferentially form around stars...

Oh to be in Hawaii for the Extreme Solar Systems III conference rather than simply following events on Twitter! The exoplanet community's choice of venues for these gatherings is hard to beat, the first of them, in 2007, having occurred on Santorini, a storied island in the Aegean Sea southeast of the Greek mainland, with a 2011 follow-up in Jackson Hole, WY. If you haven't been following events on Twitter (#ExSS3), you can at least check the full program with abstracts online, where you'll see quite a few familiar names. Alexandre Santerne's session at ExSS3 is one I wish I could have sat in on yesterday. Leading an international team, Santerne (Instituto de Astrofísica e Ciências do Espaço, Portugal) has gone to work on Kepler detections of gas giants. You would think that planets of this size would be fairly straightforward detections, but it turns out that this is not the case. In fact, Santerne and team find that half of the giant exoplanet candidates are false positives. To be...

A quick follow-up on our most recent discussion of KIC 8462852 (and thanks to all for the continuing high level of discussion in the comments) because today’s topic touches on a bit of the same ground. Centauri Dreams regular Harry Ray was first to notice a paper from Eva Bodman and Alice Quillen (University of Rochester) titled “KIC 8462852: Transit of a Large Comet Family.” From the paper: ...if the comet family model is correct, there is likely a planetary companion forming sungrazers. Since the comets are still tightly clustered within each dip, a disruption event likely occurred recently within orbit, like tidal disruption by the star. This comet family model does not explain the large dip observed around day 800 and treats it as unrelated to the ones starting at day 1500. The flux changes too smoothly and too slowly to be easily explained with a simple comet family model. I’ve only had the chance to glance at this work so far, but it’s heartening to see another paper analyzing...

Learning that our own Solar System has a configuration that is only one of many possible in the universe leads to a certain intellectual exhilaration. We can, for example, begin to ponder the problems of space travel and even interstellar missions within a new context. Are there planetary configurations that would produce a more serious incentive for interplanetary travel than others? What would happen if there were not one but two habitable planets in the same system, or perhaps orbiting different stars of a close binary pair like Centauri A and B? My guess is that having a clearly habitable world -- one whose continents could be made out through ground-based telescopes, and whose vegetation patterns would be obvious -- as a near neighbor would produce a culture anxious to master spaceflight. Imagine the funding for manned interplanetary missions if we had a second green and blue world that was as reachable as Mars, one that obviously possessed life and perhaps even a civilization....

Just a few days ago we looked at evidence that Kepler-438b, thought in some circles to be a possibly habitable world, is likely kept out of that category by flare activity and coronal mass ejections from the parent star. These may well have stripped the planet’s atmosphere entirely (see A Kepler-438b Caveat - and a Digression). Now we have another important study, this one out of the Harvard-Smithsonian Center for Astrophysics, taking a deep look at the red dwarf TVLM 513–46546 and finding flare activity far stronger than anything our Sun produces. Led by the CfA’s Peter Williams, the team behind this work used data from the Atacama Large Millimeter/submillimeter Array (ALMA), examining the star at a frequency of 95 GHz. Flares have never before been detected from a red dwarf at frequencies as high as this. Moreover, although TVLM 513 is just one-tenth as massive as Sol, the detected emissions are fully 10,000 times brighter than what our star produces. The four-hour observation...

Centauri Dreams continues to follow the fortunes of the Gemini Planet Imager with great interest, and I thank Horatio Trobinson for a recent note reminding me of the latest news from researchers at the Gemini South installation in Chile. The project organized as the Gemini Planet Imager Exoplanet Survey is a three-year effort designed to do not radial velocity or transit studies but actual imaging of young Jupiters and debris disks around nearby stars. Operating at near-infrared wavelengths, the GPI itself uses adaptive optics, a coronagraph, a calibration interferometer and an integral field spectrograph in its high-contrast imaging work. Launched in late 2014, the GPIES survey has studied 160 targets out of a projected 600 in a series of observing runs, all the while battling unexpectedly bad weather in Chile. Despite all this, project leader Bruce Macintosh (Stanford University), the man behind the construction of GPI, has been able to announce the discovery of the young 'Jupiter'...