720 XTF Search Results (expand=spectral-Type;f1-spectral-Type=Optical);f1-spectral-Type%3DOptical Results for your query: expand=spectral-Type;f1-spectral-Type=Optical Thu, 01 Jan 1970 12:00:00 GMT Starry night at Yerkes. Can you find the satellite in this time-lapse photo of the night sky over Yerkes Observatory in Williams Bay, Wisconsin? Fri, 20 Apr 2012 12:00:00 GMT Jupiter and its moons. Jupiter and its four planet-sized moons, called the Galilean satellites, were photographed in early March 1979 by Voyager 1 and assembled into this collage. Io is the moon in the upper left corner of the image, and is the moon that is closest to Jupiter. Thu, 01 Mar 1979 12:00:00 GMT Horsehead Nebula as Seen by Hubble. The Horsehead Nebula is one of the most identifiable nebulae because of the shape of its swirling cloud of dark dust and gases, which resembles to a horse's head when viewed from Earth. Thu, 01 Jan 1970 12:00:00 GMT Io - crescent with plumes. Voyager 2 took this picture of Io July 10, 1979, from a range of 1.2 million kilometers (750,000 miles). The image was part of an extensive sequence of "volcano watch" pictures of Io. The sunlit crescent of Io is seen at the left, and the night side illuminated by light reflected from Jupiter can also be seen. Three volcanic eruption plumes are visible on the limb. All three were previously seen by Voyager 1. On the bright limb Plume 5 (upper) and Plume 6 (lower) are about 100 kilometers high, while Plume 2 on the dark limb is about 185 kilometers high and 325 kilometers wide. The "volcano watch" sequence of pictures told us that these volcanoes are persistent, change with time, and are larger and last longer than those on Earth. Tue, 10 Jul 1979 12:00:00 GMT The First Black Hole. Since its discovery in 1962, the X-ray binary star Cygnus X-1 has been one of the most intensively studied cosmic X-ray sources. About a decade after its discovery, Cygnus X-1 secured a place in the history of astronomy when a combination of space-based, X-ray observations by the Chandra X-ray Observatory and optical, ground-based observations by the Digitized Sky Survey led to the conclusion that it was a black hole, the first such identification. This is an optical image of Cygnus X-1. Thu, 01 Jan 1970 12:00:00 GMT Hubble Stays on Trail of Fading Gamma-Ray Burst Fireball, Results Point to Extragalactic Origin. It is difficult to determine the origin of a GRB, but sometimes it can be done. The visible light of this GRB was detected by ground-based telescopes, and once the light had faded a deep picture by the Hubble showed this GRB was located in a faint distant galaxy Fri, 05 Sep 1997 12:00:00 GMT M100 Galactic Nucleus. This image was taken with Hubble's Wide Field and Planetary Camera 2, installed to correct Hubble's optics. The difference in clarity is dramatic and represents the realization of the anticipated quality of images from a space-based, optical telescope. Thu, 01 Jan 1970 12:00:00 GMT M100 Galactic Nucleus. This image was taken before the optics was fixed and demonstrates that the optical error generates images that are not much better than images taken with ground-based telescopes and were much less clear than expected. The picture is from the Wide Field and Planetary Camera 1. Thu, 01 Jan 1970 12:00:00 GMT Optical Crab Nebula. The Crab Nebula, some 6,000 light years from Earth, is the remnant of a supernova explosion. It was seen on Earth in the year 1054. At the center of the bright nebula is a rapidly spinning neutron star, or pulsar, that emits pulses of radiation 30 times a second. This view shows the Crab in the optical wavelength. Thu, 01 Jan 1970 12:00:00 GMT