... The New Solar System . ... Our Sun is a normal main-sequence G2 star, one of more than 100 billion stars in our galaxy. diameter : 1,390,000 km . ... The Sun is personified in many mythologies: the Greeks called it Helios and the Romans called it Sol . ... I n addition to heat and light, the Sun also emits a low density stream of charged particles (mostly electrons and protons) known as the solar wind which propagates throughout the solar system at about 450 km/sec. ... Solar Eclipse info . ... Sun ...

... NASA SPACECRAFT FINDS NEW EVIDENCE FOR WATER ICE ON MERCURY . ... The new data indicate the water ice in Mercury's polar regions, if spread over an area the size of Washington, D.C., would be more than 2 miles thick," said David Lawrence, a MESSENGER participating scientist at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., and lead author of one of three papers describing the findings. ... Water ice concentrations are derived from the hydrogen measurements. ...

Astronotes Armagh Planetarium's Stellar Blog! ... Solar System . Sun . ... March . ... The extent of the solar eclipse of 3 November€а 2013 at 13:22 UTC as seen from Accra, Ghana. We will see a similar sight.€а (Image credit: Kwabena under Creative Commons Licence) . ... Your viewing location is not important as long as it offers an unobstructed view of the south eastern sky.. ... You can use ?eclipse glasses? to view the Sun, these are made from aluminized Mylar filter material. ...

... We present a computer program for modelling energy flux distribution and light curves of eclipsing binaries from far ultraviolet to infrared regions. The Roche model is assumed. Proximity effects of components (reflection of radiation and surface gravity darkening) are taken into account. ... Figure 1: The surface temperature distribution for Algol A-B system before (upper plot) and after (lower plot) correction for temperature due to the irradiation effect. ...

... The concept of continuous solar wind developed in 1950's. First, Biermann (1951, 1957) observed comet tails as they passed close to the Sun , and explained the observed tail deflection by a continuous flux of protons from the Sun. Then Parker (1959) showed that the solar corona must expand, and called the outward streaming coronal gas 'solar wind'. ... The expanding solar wind drags also the solar magnetic field outward, forming what is called the interplanetary magnetic field (IMF) . ...

The Earth's magnetosphere global structure is conditioned by the interaction of the Solar wind and Earth's magnetic field. ... Many various magnetospheric models are available in the NSSDC . ... Fairfield D. H., Average and unusual location of the Earth's magnetopause and bow shock, J. Geophys. ... Stasiewicz K., Polar Cusp Topology and Position as a Function of Interplanetary Magnetic Field and Magnetic Activity: Comparison of a Model with Viking and other Observations, J. Geophys. ...

... Lightning Eclipse from the Planet of the Goats . ... Thunderstorms almost spoiled this view of the spectacular June 15 total lunar eclipse. ... Eclipsed Moon in the Milky Way . ... On June 15, the totally eclipsed Moon was very dark, with the Moon itself positioned on the sky toward the center of our Milky Way Galaxy. ... In an unexpected twist, recent observations have shown that the gas in the outer regions of this photogenic spiral is rotating in the opposite direction from all of the stars! ...

Jupiter is the largest of the nine planets, more than 10 times the diameter of Earth and more than 300 times its mass. ... The mean density of Earth is 5.245 times that of water. The pull of gravity on Jupiter at the top of the clouds at the equator is 2.4 times as great as gravity's pull at the surface of Earth at the equator. ... It is tipped about 11њ to Jupiter's axis of rotation, similar to Earth's, but it is also offset from the center of Jupiter by about 10,000 kilometers (6,200 miles). ...

... Science highlights . Exoplanets Disks 2016 . ... My post on the STScI science blog: "Disk, gaps, and exoplanets - a journey on the wings of a dragonfly" . ... Read here the scientific publication of this work, on the Astrophysical Journal: Banzatti Pontoppidan 2015, ApJ, 809, 167 . Read here a more poetic description on the STScI science blog: "Disk, gaps, and exoplanets - a journey on the wings of a dragonfly" . ... Do exoplanet compositions retain the imprint of large-scale disk processes? ...

... We computed the permanently shadowed areas and temperatures inside the craters for the variation of the position of the lunar pole of rotation with respect to the ecliptic pole with a period of 18.6 years. ... According to our results, the total permanently shadowed area in the polar craters of the Moon is equal to 50428.7 km2, or 0.13% of the total area of the lunar surface [3]. ... The area of permanently shaded part of a crater makes 59 % from all area of a crater [3]. ...

... Tonight's Sky . ... 50 Weirdest Objects . ... Early Mars bombardment likely enhanced life-supporting habitat . ... Astronomy for Kids . ... Observing springtime deep-sky objects with a large telescope . ... Do the gas giant planets have discernible surfaces? If so, would they support objects? ... Gas giants like Jupiter and Saturn do not have solid surfaces in the sense that if you dropped in a penny, it would never land with a clink. ... Get instant access to subscriber content on Astronomy.com! ...

... Australia Telescope Compact Array Radio Imaging of the Proplyd-like Objects in the Giant HII Region NGC 3603'' . M?cke, A., Koribalski, B.S. , Moffat, A.F.J., Corcoran, M.F., Stevens, I.R. 2002, ApJ 571, 366 . ... Brenneman, L., Corcoran, M.F., Moffat, A.F.J., Marchenko, S.V., Ptak, A., Skalkowski, G., Mushotzky, R., Stevens, I.R., Mueke, A., Koribalski, B.S. , et al. ... Physical Properties of visual counterparts to X-ray sources in the giant HII region NGC 3603'' . ...

... Australia?s 2002 Total Eclipse of the Sun . ... A total eclipse of the Sun is arguably the most awesome sight in all of nature. Day is suddenly replaced with an eerie twilight and the Sun?s brilliant disk is blocked by the dark Moon. ... This incredible spectacle is visible once every year or two when the Moon?s small dark umbral shadow races across our planet?s surface. The ensuing path of totality is typically about 150 kilometers wide but can stretch halfway around the globe. ...

Giant Jupiter. Jupiter . ... Jupiter has no solid surface that is why speaking about its dimensious point the radius of the upper border line of the clouds, where the presseru is about 10 KPa; radius of Jupiter on the equator is 71400 km. ... The Jupiter satellites. ... Nowadays 16 satellites of the Jupiter are known: Adrastea, Mitis, Amaltea , Phina,then 4 Galilei satellites: Io , Europe , Hanimed , Callisto , Leda, Aimalia, Zicitea, Elara, Ananke, Carme, Pasipe and Sinope. ... Jupiter's ring. ...

... Sun images . ... Sun flares . ... Active areas . September : 2009 . ... No sunspots and sunspot groups can be currently observed on the Sun's surface . The following H-alpha plages without spots can be currently observed on the Sun's surface . ... Coordinates . ... Coordinates and other characteristics of active regions are issued for September 09, 2009 00:31 UT . Last updated: September 10, 2009 00:00 UT . ... 7(499)132-65-96, Fax: +7(499)132-65-97 . ...

The SOHO spacecraft currently supplies daily images of the solar corona at 1.1-3, 2-6 and 4-30 solar radii. Are ground-based solar corona observations during total solar eclipses have becoming obsolete nowadays? A quick view of SOHO data shows that it is not perfect in some respects. ... On March 9, 1997 an expedition has been organized by the Russian Academy of Sciences to the Baikal region in Siberia for observation of the total solar eclipse. ... Fig. ... Lens: F = 1m, D = 170 mm . ...

Class 1 Introduction, Background History of Modern Astronomy The Night Sky, Eclipses and the Seasons Kepler's Laws Newtonian Gravity General Relativity Matter and Light Telescopes Class 2 Solar System Characteristics Formation Exosolar Planets Class 3 Stars The Sun Stellar Evolution of Low and High Mass Stars Deaths of Stars Exotic Stars Class 4 Galaxies Galaxy Classification Formation of Galaxies Galactic Evolution ... So far, one planet has been studied by this method. ...

... Conjunction Over Armagh . ... Comet and Pleiades . ... Pleiades . ... Antares Region . Helix and Cat's Eye Nebulae . Orion Nebula . Lagoon and Eagle Nebulae . Crab Nebula . ... Our Galaxy Core . Andromeda Galaxy . Wide-field and Zoomed-in Galaxies . Interacting Typhoons and Galaxies . Spiral Galaxy M106 . Sombrero Galaxy . Whirlpool Galaxy . Colliding Galaxies . ... й Miruna Popescu, Armagh Observatory ...

... galaxies: bulges galaxies: clusters: general galaxies: clusters: individual: . ... star formation statistics stellar content structure Cosmology ( cosmology :) cosmic background radiation ( cosmology :) cosmological parameters cosmology : miscellaneous cosmology : observations cosmology : theory ( cosmology :) dark ages, reionization, first stars ( cosmology :) dark energy ( cosmology :) dark matter ( cosmology :) diffuse radiation ( cosmology :) distance scale ( cosmology :) early Universe (...

... More on 51 Peg: . The discovery of a Jupiter--mass planet in orbit around the solar--type star 51Peg has been reported by Michel Mayor and Didier Queloz (Geneva Observatory) on October 6th at the 9th Cambridge workshop on "cool stars, stellar systems, and the sun" held at Florence (Italy). ... Recall that the measurements of radial velocity only yield v sin i which in turn gives us M sin i. For most values of i, sin i will be greater than 0.5 and this gives a mass estimate of 0.5 Jupiter masses. ...