Astronomy Picture of the Day . A Colorful Aurora . ... 1.09.1998 . ... Credit: Stephen Barnes , Sky Optics Explanation: A solar storm overtook the Earth on August 26th. ... Solar particles that strike oxygen high in Earth's atmosphere cause rare, red auroras , while oxygen lower to the ground will glow a more familiar green. ... Publications with keywords: aurora - Earth - atmosphere . Publications with words: aurora - Earth - atmosphere . ... Earth at Twilight . ... Aurora in the Distance . ...

... 2002 September 2 . Colorful Light Pillars . ... In most places on Earth, a lucky viewer can see a Sun-pillar , a column of light appearing to extend up from the Sun caused by flat fluttering ice-crystals reflecting sunlight from the upper atmosphere. ... These ice crystals may then reflect ground lights in columns not unlike a Sun-pillar . In the above picture, the colorful lights causing the light pillars surround a ice-skating rink in Fairbanks, Alaska . ... About APOD | ...

... HST . Reporting Problems with and Requesting Changes to Approved HST Programs . ... Data . ... Annual Reports . ... HST Peer Review Process . ... HST Overview . Overview . ... Cycle 24 Announcement . ... Changing Programs & Resolving Problems . ... Reporting Problems . Retrieving HST Data . ... Program Change Requests . ... Hubble Observation Problem Reports . Proceed to the Program Information Page for the program in question, and use the appropriate links on that page. ...

... A2130 (galfacts) reported strong rfi (lots of overflows from the mock spectrometer) on the evening of 02nov11. The punta salinas frequency agile radar was running in all frequencies until about 20:00 ast (it then changed to mode A 4 frequency mode). ... The variation in counts by session may be the beating of when the dome was at certain za's vs when the radar pointed at the observatory. punta salinas radar ran in all frequencies for the first part (till 20:00 ast) of the a2130 run on 02nov11. ...

... 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! ...

... September 5, 1998 . The Pulsar Powered Crab . Credit: J. Hester and P. Scowen ( ASU ), NASA . ... Using a stunning series of visible light images taken with the Hubble Space Telescope (HST) , astronomers have discovered spectacular pulsar powered motions within the Crab nebula. Highlights of this HST Crab "movie" show wisps of material moving away from the pulsar at half the speed of light, a scintillating halo, and an intense knot of emission dancing, sprite-like, above the pulsar's pole. ...

... DFS Department Problem Reporting rules and recommendations . ALL change requests, bugs or support request on operational releases (i.e. releases already installed and running on the mountain) must be reported via the DFS Problem Reporting tools , based on the Action Remedy system. ... in case of bug, change request or support need directly reported to you via mail or phone call by s DFS user (Paranal, La Silla, DFO, ...), please, check whether an Action Remedy Problem Report is already open. ...

Changes SciSim v2.0.3 . SciSim v2.0.3 is a bug fix release of SciSim and contains only minor changes compared to v2.0.2. The input (configuration & data) files, as well as the ODF products are compatible with previous versions. ... EDUID is currently coupled to ccd id. ... Iterpretation of Quadrant and CCD numbering has changed (see also the ESIM documentation in the SciSim User Guide). ... The following README files specify the changes in the data-files and in the configuration file: . ...

... Radio Catalog . The corrections in NVSS fluxes leading to the corrected Version 1.1 also result in changes to some of the figures and tables in Kimball Ivezi? ... The results are qualitatively the same. ... The new versions of the figures, along with the original versions (in high resolution), are available here . ... These figures, along with Table 4, continue to motivate t = 0.35 as the optimal separator between "simple" and "complex" sources). ... Complex Sources . ... t NVSS . ... galaxy . ...