Word: ghez
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...paintings, porcelain and objets d'art. The current temporary show, like the museum, is a small gem, although the title From Caillebotte to Picasso is a little misleading. Only one Picasso and two Caillebottes are on display. The rest of the 85 paintings and sculptures, all from the Oscar Ghez collection at Geneva's Petit Palais, cover modern art between 1870 and 1950: Impressionists, Neo-Impressionists, Nabis, Fauves, Cubists and Surrealists. Many of the names are second-tier - Marie Bracquemond, Charles Angrand, Henri-Edmond Cross, Suzanne Valadon - but most of their works (especially Bazille's Family Reunion...
UCLA astronomer Andrea Ghez, meanwhile, has focused her attention on the center of our home galaxy, the Milky Way, far closer than Djorgovski's gamma-ray bursts but hundreds of times farther away than Marcy's planets. Shrouded in thick clouds of dust, the galactic core is invisible to ordinary light detectors. But among the Keck's suite of specialized instruments is an electronic camera sensitive to infrared light--the same kind of invisible light that your remote control uses to communicate with your TV. Infrared light of some wavelengths can penetrate dust as though it weren't there, giving...
Armed with the combination of the Keck's power and the detector's sensitivity, Ghez has been able to measure the motions of stars that lie 100 times as close to the core as the nearest star, Proxima Centauri, lies to the sun, and he finds that they're whipping around the galactic center at 1,600 miles per second, nearly 100 times as fast as Earth orbits the sun. It only takes high school physics to calculate that the object they're orbiting is as massive as 3 million suns yet packed into an area no bigger than...
...only thing that reasonably fits this description is a black hole, an object whose gravity is so strong even light can't escape from it. "We have evidence of these supermassive black holes in several other galaxies," says Ghez, "but this is the most convincing case we know...
Even with these limitations, astronomers at both the Keck and Gemini have taken pictures that are every bit as clear as the Hubble's. Clearer, in fact, because a large telescope's images are inherently sharper than a small one's. Indeed, Ghez's latest and sharpest Keck images of the galactic center have been made with the adaptive optics...