... The TRACE images may be used without restrictions in publications of any kind. ... These two images, taken on 18 November 2000 at 15:54UT and 16:11UT, respectively, show such an event: the red circle in the image to the left shows a region where many loops are cooling, with bright loop tops (the intensity scales with the square root of the image to reduce the dynamic range). ... See also a collection of images related to the Sun, other cool stars, and solar-terrestrial effects . ... Images | ...

... A typical density of energetic ions is 1 per cubic cm., and the ions are matched by electrons, generally of lower energy. ... This region is almost empty of plasma--typical density 0.01 ion/cubic cm., the "best vacuum" in the Earth's vicinity--but it contains a relatively strong magnetic field which, since it fills a large volume, can store appreciable magnetic energy, Many believe that this is the storehouse from which substorms draw their energy, releasing it quite rapidly. ...

... Magnetic Storms . ... Cosmic Rays . ... Energetic Particles . ... Solar fast Particles . We cannot observe the way the distant universe accelerates cosmic rays or produces energetic photons, but acceleration processes also occur on our Sun , though on a much more moderate scale. ... That is why such events are often missed by cosmic ray detectors near the equator, where the lowest energies are excluded by the Earth's magnetic field. ... Should we be concerned about solar energetic radiation? ...

... The concerns here are similar to those for observing bright targets; saturation and blooming of the bright companion PSF must not impact the faint target. Also, one may need to consider subtracting the PSF of the bright object, and effects which limit the accuracy of that subtraction. If the bright companion will saturate and bloom, it will be necessary to rotate the CCD so that blooming along the CCD columns does not obliterate the faint target. ...

... High spectral, spatial and temporal resolution UV observations of the quiet Sun transition region show a highly structured and dynamical environment where transient supersonic flows are commonly observed. ... Estimates of the kinetic and enthalpy fluxes associated with these events show that explosive events are not important so far as solar coronal heating is concerned. ... In some cases, non-Gaussian line profiles are associated with supersonic flows in small magnetic loops. ...

... Research objects and scientific purposes . Space scientific program includes development and launch of two supersmall spacecrafts "Universitetskiy" and "Kompas-2" intended for monitoring of radiation conditions near the Earth. ... All the studies conducted in the near-Earth space are characterised by strong radiation fields. ... The circular polar orbits, which cover all the near-Earth space, are the most favorable for comprehensive studies of the radiation conditions near the Earth. ...

... About ATNF overview . ... Australia Telescope Steering Committee . ... LMC H II Region Luminosities versus . Observed Ionizing Stars . ... These values are compared to the observed H II region luminosities, yielding an estimate for the mean fraction of H-ionizing photons that escape the local nebulae in this sample. We formally estimate that, overall, 0-51% of the ionizing radiation escapes the local H II regions and is available to ionize the warm, ionized medium in the LMC. ...

... This thread contains a step-by-step recipe to extract MOS spectra of a point-like source observed in Imaging mode and to create associated response matrices, starting from a calibrated, concatenated event list (either produced with emproc or available as PPS product; here it has the assumed file name MOS.fits ). ... The users should note that the SAS metatask xmmselect allows them to interactively define source and background regions (via ds9) and to run backscale on the fly. ...

... What could cause a star to have such a large spot? Our Sun itself frequently has sunspots, relatively cool dark magnetic depressions that move across its surface. ... The Cat's Eye Nebula (NGC 6543) is one of the best known planetary nebulae in the sky. ... But on August 29th the red planet Mars, near it's closest approach to Earth in almost 60,000 years, shone brightly in the sky against a background of stars in the constellation Aquarius. ... A Powerful Solar Flare . ... Mars Moons . ...

... Height from the galactic plane 65- 75 A11 --- IRAS IRAS name 81 A1 --- l_F12 limit flag on F12 (upper limit ) 83- 90 E8.2 Jy F12 IRAS flux density at 12 micron 92 A1 --- l_F25 limit flag on F25 (upper limit ) 94-101 E8.2 Jy F25 IRAS flux density at 25 micron 103 A1 --- l_F60 limit flag on F60 (upper limit ) 105-112 E8.2 Jy F60 IRAS flux density at 60 micron 114 A1 --- l_F100 limit ...

... 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 . ...

Polycyclic aromatic hydrocarbons in HII regions: correlation with metallicity . ... We have perfomed the aperture photometry of HII regions using infrared images from telescopes Spitzer and Herschel at passbands 3.6, 4.5, 5.8, 8.0, 24, 70 and 160 m. Emission of PAHs are observed at passbands 3.6 - 8.0 m, 24 m is emission likely of hot small particles and finally large particles are responsible for emission at 70 and 160 m. We determine abundances of PAHs using model of Draine Li (2007) . ...

Most current theories for magnetospheric emission can be grouped into polar cap, outer gap, and nebular models. These models, at least in some cases, need not be mutually exclusive; the Crab pulsar (among others), for example, shows clear evidence for pulsed emission from the magnetosphere and unpulsed emission from the surrounding nebula. ... This suggestion is strengthened by observation of a distinct soft emission component, consistent with the cooling scenario, from several of these pulsars. ...

... Science Users Information > Science Activities > PhD Thesis Topics offered by ESO Faculty Members > Thesis Topic: Planetary Nebulae and HII regions in the Elliptical Galaxy NGC 5128 . ... NGC 5128 is the closest example of a giant early type (elliptical or S0) galaxy. Although often dubbed as a peculiar elliptical galaxy since it has a dust lane with recent star formation and an active galactic nucleus, the majority of early type galaxies have similar structures as revealed by recent surveys. ...

... We report on our ongoing project ``Infrared Study of HII Regions Associated with Small Clouds.' ... These IR data, combined with optical imaging (which will be obtained from the IAC-80 telescope), IRAS survey maps, and existing CO observations of the associated clouds, will allow us to undertake a detailed investigation of the gas-to-dust mass ratio, initial mass function and the star-formation efficiency in these complexes. ... CHECKPSF: check the PSF (Point Spread Function) model, . ...

... A1 centered at 2500 angstroms with a width of 1200 angstroms . ... M63 or NGC 5055 is a pleasant spiral galaxy with multiple arms and a bright inner region. The exposure times were 1149 seconds through B1 and 576 seconds through A1. NGC 752 a galactic stellar cluster was observed for 777 seconds through B5 . ... NGC 1365 is a prominent spiral galaxy in the Fornax Cluster. ... The galaxy fits comfortably into one UIT frame and this exposure was for 1360 seconds through A1 and B1. ...

... 1994: . Deep CCD images of the bright gamma-ray bursts GRB790418 and GRB790613 localization regions were obtained for the first time. In both cases, a faint blue star-like object (V = 24.5 m , BV m ) was detected within the region of localization of gamma-ray bursts. ... Based on sixty daily instantaneous spectra of the object SS433, obtained on the RATAN-600 in April-May 1994, we traced its variability in four very powerful flares at five frequencies. ... Archive . ...

. Statistics of sunspot activity . The sunspot indices . My observations . NGDC's observations . The solar regions . Links . About authors . Russian pages . The solar regions . NOAA 11300's . NOAA 11200's . NOAA 11100's . NOAA 11000's . NOAA 10900's . NOAA 10800's . NOAA 10700's . NOAA 10600's . NOAA 10500's . NOAA 10400's . NOAA 10300's . NOAA 10200's . NOAA 10100's . NOAA 10000's . NOAA 09900's . NOAA 09800's . NOAA 09700's . NOAA 09600's . NOAA 09500's . NOAA 09400's . NOAA 09300's .

... Observing . ... Solar Observing . ... April 3 (SUN) - Solar Observing, Central Park , Manhattan . ... APRIL'S SKY . ... Lecture Series at the American Museum of Natural History The Amateur Astronomers Association is proud to present an astronomy lecture series from October through May each year for our members and the .. ... The€аAmateur Astronomers Association of New York€аwas organized in 1927 to promote the study of Astronomy, emphasizing its cultural and inspirational value. ...

LARGE-SCALE PHENOMENA AT THE SUN ASSOCIATED . WITH FILAMENT ERUPTIONS OUTSIDE ACTIVE . ... Considering the 12.09.1999 event as an example, we analyze manifestations of large-scale disturbances associated with coronal mass ejections (CMEs) caused by filament eruptions outside of active regions. ... The filament eruption occurred in relatively weak magnetic fields, but it was accompanied by larger-scale phenomena than flare events do. ...