... January 4, 1997 . A Star Where Photons Orbit . ... Explanation : The above computer animated picture depicts how a very compact star would look to a nearby observer. ... From here one can either look down and see several duplicate images of the entire surface of the star, look up and see several duplicate images of the entire night sky, or look along the photon sphere and see the back of one's own head. Tomorrow's picture: Too Close to a Black Hole . ... About APOD > . ...

... Observers looking at an object that is moving away from them see light that has a longer wavelength than it had when it was emitted (a redshift), while observers looking at an approaching source see light that is shifted to shorter wavelength (a blueshift). ... By measuring the amount of the shift to the red, we can determine that the bright galaxy is moving away at 3,000 km/sec, which is 1 percent of the speed of light, because its lines are shifted in wavelength by 1 percent to the red. ... Part 2...

... Tonight's Sky . ... Sky this Month . ... Star Atlas . ... stars . ... The Sky This Week: April 1 - 10 . ... Observing springtime deep-sky objects with a large telescope . ... Why do some stars appear to flash a variety of different colors when you look at them through a telescope? ... So, Earthт??s atmosphere will bend some colors from especially bright stars more so than others, which makes the source look like itт??s flashing colors. Get instant access to subscriber content on Astronomy.com! ...

... 29a. Satellite looking up . 29c. Satellites probing around . ... The US Air Force furthermore sponsors polar satellites of the DMSP series, scanning the cloud cover of the polar region and also studying ions and electrons of the magnetosphere. ... The Canadian satellite Alouette in 1962 bounced radio signals off the top of the ionosphere, and UARS (Upper Atmosphere Research Satellite) has studied the Earth atmosphere. ... Next Satellite Class: #29c Those observing local conditions . ...

... August 30, 1999 . Looking Back on an Eclipsed Earth . ... Explanation: Here is what the Earth looks like during a solar eclipse. ... Only observers near the center of the dark circle see a total solar eclipse - others see a partial eclipse where only part of the Sun appears blocked by the Moon . This spectacular picture of the 1999 August 11 solar eclipse was one of the last ever taken from the Mir space station , as Mir is being decommissioned after more than ten years of productive use. ...

These include satellites which monitor the weather, such as the GOES series (one of which is shown on the right) of the US National Oceanic and Atmospheric Administration (NOAA). ... To this class also belong "spy satellites" which observe the ground from low circular orbits. ... The Canadian satellite Alouette in 1962 bounced radio signals off the top of the ionosphere, and UARS (Upper Atmosphere Research Satellite) is currently studying the Earth atmosphere. ...

... The Sun . Does anyone know how many stars are there in the solar system? Come take a look at the Sun. See that? ... Did you know all the stars you see when you look up are inside our galaxy! ... Did you know that our Sun and solar system were born in a cloud of gas and dust like this. ... We're looking at a place where stars are being born. ... Sharing the Universe is based upon work supported by the Informal Education Division of the National Science Foundation under Grant no DRL-0638873. ...

... NGC 7129 and NGC 7142 . ... This alluring telescopic image looks toward the constellation Cepheus and an intriguing visual pairing of dusty reflection nebula NGC 7129 (left) and open star cluster NGC 7142. The two appear separated by only half a degree on the sky, but they actually lie at quite different distances. ... Tethys, one of Saturn's larger moons at about 1000 kilometers in diameter, survived the collision, but sports today the expansive impact crater Odysseus. ... August . ...

This is the homepage of Andrew Fruchter, an astronomer on the staff of the Space Telescope Science Institute . ... Here you can look at an HST images of the optical counterparts of gamma-ray bursts and their host galaxies. ... Therefore, substantial information on the fine scale structure of objects can be obtained by offsetting the pointing of the telescope between exposures and then combining these "dithered" exposures into a single image. ...

... mar05: filter bank installed but left in wide band mode. 05apr05: 10db amps placed in pixel 2a,2b path in front of the filter bank. 08apr05: 10db amps placed in front of filter bank for all alfa pixels. 12apr05: 6db attenuators placed before 10db amps. 25apr05: 10db amps are now only in the OH filter bath. ... This allowed the search of the data taken by P2030 (100Mhz bandwidth, cfr 1420Mhz, 64usec samples) between 01feb05 and 01may05 for signals of the aerostat radar. ...

... Under certain conditions, like those in the nucleus of a QSO, all atoms can be made to emit light at particular wavelengths. ... If that source is approaching the observer, the wave is squashed up onto itself making the wavelength shorter. ... This is redshift. ... You can see how the section of the QSO spectrum which we observe changes with redshift. ... We then see how far we had to slide the observed spectrum along the scale to make it match and that is the objects redshift. ... The 2QZ team . ...

... Bad Astronomy . Misconceptions . ... But what if they make Bad Astronomy there? ... But they aren't; what looks like a flat painting of stars on a canvas is actually a three-dimensional tapestry of stars at varying distances, the least of which is still tremendously far away. ... Look at the conste