... 2007 November 25 . An Iridescent Cloud Over Colorado . ... Explanation: Why would a cloud appear to be different colors? A relatively rare phenomenon known as iridescent clouds can show unusual colors vividly or a whole spectrum of colors simultaneously. ... When the Sun is in the right position and mostly hidden by thick clouds, these thinner clouds significantly diffract sunlight in a nearly coherent manner, with different colors being deflected by different amounts. ... About APOD | ...

... An Iridescent Cloud Over Colorado . ... 25.11.2007 . ... Credit: August Allen Explanation: Why would a cloud appear to be different colors? A relatively rare phenomenon known as iridescent clouds can show unusual colors vividly or a whole spectrum of colors simultaneously. ... When the Sun is in the right position and mostly hidden by thick clouds, these thinner clouds significantly diffract sunlight in a nearly coherent manner, with different colors being deflected by different amounts. ...

... Bad Astronomy . ... Bitesize Astronomy . ... Last week's Snack talked about how black holes can affect the environment around them in such a way as to be very bright . ... It's a common misconception that black holes always have matter swirling into them. ... As this matter gets closer and closer to the black hole it piles up and a large, fairly flat disk forms. This is called the accretion disk , because matter from this disk accretes (that is, falls in) on the black hole. ... 2008 Phil Plait. ...

... 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! ...

Crater Gassendi . ... I made this drawing was made on the 26th of november 2001. If you compare this one with the previous drawing of Gassendi (below) the differences are clear. ... This drawing was made on the 28th of september 2001. After nearly a full month without observations I had a one hour gap between the thicker clouds. ... This drawing was made on the 29th of august 2001. ... This drawing was made on the 27th of august 2001. ... This drawing was made on the 25th of august 2001. ...

... The Pleiades star cluster, also known as the Seven Sisters and Messier 45, is a conspicuous object in the night sky with a prominent place in ancient mythology . ... The stars in the Pleiades are thought to have formed together around 100 million years ago, making them 1/50th the age of our sun, and they lie some 130 parsecs (425 light years ) away. ... Data for these stars are listed in a table below. ... Yes . ... WEBDA Pleiades cluster data . ... M45: The Pleiades Star Cluster (2007 November 18) ...

... August 6, 1998 . Infrared Horsehead . ... Explanation: This famous cosmic dust cloud was imaged in infrared light by the European Space Agency's Infrared Space Observatory (ISO) satellite. The false-color picture shows the bright infrared emission from dust and molecular gas in part of the Orion star forming region surrounding the Horsehead Nebula . In visible light, the horsehead-shaped dust cloud looks dark against a background of bright glowing gas. ... About APOD > . ...

M1 image More About M1 Nice Color Picture . ... M16 image More About M16 HST image . ... M31 image More About M31 Nice Color Picture . ... M42 image ; M43 image More About M42/43 Nice Color CCD Picture . M51 image More About M51 Color Image of M51 M51 Supernova . M57 image More About M57 Nice Color CCD Picture Very Deep M57 Image . ... M81 image More About M81 M81 Supernova Ultraviolet Image of M81 More about Ultraviolet Imaging . M82 image More About M82 M82 False Color M82 True Color . ...

Astronotes Armagh Planetarium's Stellar Blog! ... Space Flight . ... Earth Satellites . ... Leonid meteors seen from 13 km altitude aboard an aircraft during the 1999 Leonids Multi-Instrument Aircraft Campaign (Leonid-MAC). Comet Tempel-Tuttle provides the cometary debris for the Leonid meteor shower. ... Every 17-19 November Earth crosses Tempel-TuttleтАЩs orbit and the Leonids become visible. With clear, dark skies observers may see 10 to 15 Leonid meteors every hour on those mornings. ...

Making HST Pictures: Examples and Illustrations . ... These illustrations represent some of the steps and techniques used to produce “pretty pictures” from HST images. ... TIFFs (ftp) . ... Separate images are exposed through different color filters. ... An alternate way to make color images . ... Eight bit (one byte) images contain 256 different values that may be represented by 256 shades of gray or 256 arbitrary colors from a color map (or palette) of all possible colors. ...

... Posts tagged ?Efron? ... The notions of missing data are overall different between two communities. ... Tags: bootstrap , catalog , Efron , estimator , ignorable , imputation , incompleteness , Little , MAR , MCAR , missing data , nonparametric , Rubin , Schafer , survey . ... 2 Comments . ... Astronomers confront with various censored and truncated data. ... Tags: censored , Efron , Feigelson , Freedman , massive data , Nelson , Petrosian , survival analysis , truncated . ... Comment . ...

... 2 April 1999 . The Nobeyama Radioheliograph data show that in the microwave range, besides large-scale trans-equatorial chains (see, e.g., the May 11-15, 1993 and November 1-4, 1993 events), there are also many examples displaying large and strongly evolving "longitudinal" or "internal" chains connecting remote active regions inside an active zone in one (northern or southern) hemisphere (the August 20-September 3, 1998 event). ... Last update: 2 April 1999 . ...

Browse the articles below for new ideas for your classroom. Mercury September/October 2005: Astronomy Education and Public Outreach: Steps and Missteps Toward an Emerging Profession (pdf) . Focus on Education articles as they appeared in Mercury: . ... March/April 2000: . ... Education Newswire articles as they appeared in Mercury, by issue. ... January/February 2000 . November/December 1999 . ... March/April 1999 . ... November/December 1998 . ... November/December 1997 . ...

... Home Astro-Imaging g3-efox8632-m82-e-600-c-35-x1-color-001-ut080815_ep1 . ... Lecture Series 2014-2015 . ... AAA Fall Astronomy Class: Astronomy Basics тАУ October-November 2015 . ... Clear Sky Chart . This Month's Sky . ... Beyond New York City . ... Observing Resources for Amateur Astronomers - Part 1: Beginning Observers . ... A History of the First Forty Years of the Amateur Astronomers Association . ... 2016 Amateur Astronomers Association of New York Designed by Press Customizr Powered by . ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . Noctilucent clouds as photographed by Mark Bailey from Lisdoart on 14th July 2006 at 11.30 pm. ... These so-called noctilucent (night glowing) clouds (NLCs), are formed by sunlight reflecting off ice crystals high in the atmosphere, and usually appear in the northwest, through north to northeast during twilight in the late spring and summer months at our latitude. ...

... Circumstellar disc of beta Pictoris: constraints on grain properties from polarization. To appear in the Astronomy & Astrophysics . abs , src , ps ] . ... Dust influx to Titan from Hyperion . ... abs ] . ... Characteristics of bulges and disks in interacting galaxies . ... Dust grains around Herbig Ae/Be stars: porous, cometary-like grains? ... To appear in the Astronomy & Astrophysics Supplement . ... Finally, Links may lead you to more options (e.g. via the LANL preprint system). ...

... This is a preliminary summary of the event on November 24, 1996, considered during the INTERBALL Workshop in Kiljavanranta, Finland, February 1998. ... Pronounced plasma sheet thinning (Bz decrease) . ... Particle burst observed inside the Polar Cap and in tail lobes . A short burst of particles detected by the Auroral Probe particle detectors during the Polar Cap crossing at 21:45 UT, almost simultaneously with the Tail Probe detectors registration of the particle burst inside the North Lobe. ...

... About ATNF overview . ... Governance overview . Australia Telescope Steering Committee . ... Visitor list . ... Parkes radio telescope . ... Parkes | ... Visiting Parkes radio telescope . ... Parkes radio telescope webcam . ... What is a pulsar? ... Group . ... Parkes Pulsar Observing Wiki . ... Pulsar Groups . ... Main / . ... Nov 1, 2010 - Jan 31, 2011 . ... Dec 8 - 17, 2009 . ... Dec 13 - 23, 2006 . ... Dec 3, 2006 - Jan 5, 2007 . ... Aug 10 - Dec 7, 2006 . ... Dec 31, 2005 - Feb 1, 2006 . ...

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... Data Reduction FAQ > The reduced science spectrum displayed in the Reflex window appears good but when I try to plot it, it is quite different. How can I get it? ... Observing with ESO Telescopes . ... ESO-MIDAS . ... Reflex . ... ESO Data . ... ESO HST Image Galleries . ... ESO Data Access Policy . ... ESO Science Newsletter . ... ESO Annual Reports . ... Seminars at ESO Santiago . ... Seminars at ESO Garching . ... ESO Telescope Bibliography . ... Last Update: 01.04.14 ESO . ...