... To be read in conjunction with Section 4.11 of the WFPC2 Instrument Handbook , -Version 4.0. ... 1 The second study found evidence that CTE loss for faint stars has increased with time (Whitmore, 1998). The primary observational consequence of CTE loss is that a point source at the top of the chip appears to be fainter than if observed at the bottom of the chip, due to the loss of electrons as the star is read out down the chip (see Figure 1 ). ... Last updated: 06/16/98 10:38:00 . ...

Numerical simulation of electromagnetic scattering by morphologically complex objects Janna M. Dlugach*, Michael I. Mishchenko** *Main Astronomical Observatory of the National Academy of Sciences of Ukraine, Kyiv, Ukraine **NASA Goddard Institute for Space Studies, New York, USA Radiation mechanisms of astrophysical objects: classics today 21 ­ 25 September, 2015, St.Petersburg. ... Phase angle dependence of the degree of linear polarization for the center of the Jovian disk. ...

... 2009 October 29 . Zodiacal Light Over Laguna Verde . ... Once considered a false dawn , this triangle of light is actually Zodiacal Light , light reflected from interplanetary dust particles . ... The band of our Milky Way Galaxy on the left mirrors the zodiacal band. ... Zodiacal light is so bright in the north this time of year because the dust band is oriented nearly vertical at sunrise, so that the thick air near the horizon does not block out relatively bright reflecting dust . ...

In this gallery are many images of Low Surface Brightness Galaxies which have recently been discovered and analyzed. ... The central surface brightness of this galaxy is 24.28 . Malin 2 This galaxy is another huge disk galaxy with a scale length of 15 kpc and a redshift of 15000 km/a. The high surface brightness knot in one of its spiral arms actually has the same color, luminosity and H-alpha equivalent width as the entire Large Magellanic Cloud . ... Truly it is a Low Surface Brightness Galaxy. ...

... It is found that the correlation coefficients between these two parameters calculated separately inside and outside the sunspot formation zone ±30 have cyclic variation and occur in anti-phase. This suggests different mechanisms of formation of the corona in the fields of small, medium, and large scales. ... The relationship between the coronal green line brightness (CGLB) and the magnetic field strength (MFS) has been investigated by constructing the corresponding synoptic maps for the 1977-2001. ...

Next: SAS processing Up: Maintenance procedures Previous: Maintenance procedures Contents . Suitable observations should be longer than about 20 ksec, cover all the considered time period, and have different background levels, in particular the highest ones, so the sample should include observations taken at the beginning and end of the science window. It is helpful to consider objects for which no RGS spectrum is expected or to look at the RGS monitor pages. ... Michael Smith 2011-09-20 ...

... Particle Sizes in Saturns Rings . ... What size particles compose Saturn's rings? To help find out, the robot Cassini spacecraft now orbiting Saturn broadcast radio waves of three different wavelengths right through the rings to Earth earlier this month. Swirls and Stars in IC 4678 . ... What causes small waves in Saturn's rings? Observations of rings bordering the Keeler gap in Saturn's rings showed unusual waves. ... Deep Impact Spacecraft Hurtles Toward Comet . ...

... It provides long range planning information to the scheduling team; it provides bright object, timing, and orientation information to the observation planning team; and it provides graphical description of the observations and their constraints. ... The GUI graphically displays the constraints that are computed by Spike and stored in the description files and in the database. ... BOAS processes all bright objects that have entered the database since the last time BOAS was run. ...

... The dayside auroral precipitation consist of magnetosheath related boundary layer precipitation, and plasma sheet related BPS/CPS precipitation (extensions of the nightside precipitation regions). ... For example, the much lower fluxes from the LLBL region when compared to the cusp are compensated by the bidirectional electron beams found in the LLBL: the precipitating energy fluxes in the LLBL and the cusp are not that different. ... directly through the cusp and plasma mantle . ...

Imaging photometry of the optical continuum during Deep Impact Tanyu Bonev1 and Klaus Jockers Max Planck Institute fЭr Aeronomie · Feasibility · Brightness and color measurements of a disintegrated comet · Simulations of the impact ejecta dust cloud · Conclusions 1 on leave from I nsti tute of Astronomi e, Bulgari an Aca demy of Sc i ence s Feasibility or · What we know about the dust coma of comet 9P/Tempel? and · Is the material added by the impact sufficient to be detected? ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... Circular polarization of the bright side of Iapetus versus wavelength, obtained with FORS2 at the ESO VLT during the night 2011-03-28 at a phase angle of 0.77 . ... It can be noted that a change in signal occurs in circular polarization observations that are taken after rotating the instrument by 90 degree with respect to the intial position angle on the sky. ...

The spectrophotometrical complex of the 6-m telescope in Nasmyth-1 focus . ... A new sample of 360 blue compact galaxies with a strong star formation was build on the base of the Second Byurakan Survey. ... More that 20 galaxies with the extremely low-abundances of heavy elements in the range of 1/30-1/10 of the Sun's one, were found. ... During the 15-years observation term near 500 spectra of the unique source SS~433, from which the relativistic jets were found for the first time, were obtained. ...

11 august 2014/Monday: Arriving, Registration . ... The variation of solar flare coronal X-ray source spatial properties. ... Melnikov V.F., Charikov Yu.E., Kudriavtsev I.V. Directivity of X-ray and gamma-ray emission from different parts of flaring magnetic loops. ... E., Melnikov V.F. Angular characteristics of polarization degree of hard X-ray emission from different parts of flaring magnetic loops. ... The thick target model and analytical calculations of the hard X-ray emission from solar flares. ...

... The ancient chronical said about the colour rings around the Sun and the Moon, about three suns in the sky, light columns, bright lightning, different "comets" rushing to the Earth, moving among the stars or round the Earth with the sky. All these occurrences may be divided into three categories: one that occur in the near or far space, processes going on in the Earth atmosphere under the influence of cosmic factors and at last the occurrences connected with the Earth atmosphere. ... Rainbow . ...

Next: Some theory Up: userhtml Previous: Calibration . By many measures, the ATCA 3-mm observing band is a completely different domain to the other ATCA bands. ... Not surprisingly many aspects of the data reduction are also different. This chapter reviews the theory behind some of the differences, and then considers a practical approach to calibration. ... Antenna gain considerations and flux calibration . Instrumental phase . Atmospheric phase and phase calibration considerations . ...

... In one situation, we can use light from quasars to probe the material between us and them because that light may pass through one or more galaxies or gas clouds on its way to us. The gas inside the galaxies or the intergalactic clouds acts then as a filter, absorbing selected wavelengths from the quasar light. ... Light from a quasar must pass through clouds of gas and even faint galaxies -- each leaving its imprint on the light -- before we receive it here on Earth. ... Gravitational lensing . ...

These NASA Hubble Space Telescope pictures of comet Hale-Bopp show a remarkable "pinwheel" pattern and a blob of free-flying debris near the nucleus. The bright clump of light along the spiral (above the nucleus, which is near the center of the frame) may be a piece of the comet's icy crust that was ejected into space by a combination of ice evaporation and the comet's rotation, and which then disintegrated into a bright cloud of particles. ...

Physical and dynamical parameters of particles in outbursting Comet 17 P/Holmes . ... The time depending offset between the center of brightness and center of mass of the comet nucleus has been determined on the ground of positional observations of the comet. ... The motion of these particles allowed subsequent offset between the center of brightness and center of mass of the comet nucleus to be obtained from positional observations. ... comet, dynamical model, outburst, brightness. ...

... In order to compare the number of different evolutionary stages obtained and X-ray luminosity of the chosen X-ray sources with the observed galactic values we use the sum of C/O+O/C , where C and O are the calculated and observed values of a given binary type, respectively. If we make comparison for a number of different binary species (for example, we compare the number of CV, number of X-ray pulsars,   total X-ray luminosity of LMXB, etc.), we write this criterion in the form: . ...

This page is devoted to information on Supernova 1999gn in NGC 4303 (= M61 ) Basic information on this SN, including the last reported brightness, on this Supernova can be found on the main supernova page. Information on the original web pages for many of these images can be found on the Supernova links web page. ... SEDS has a Supernova 1999gn page . ... Seiichi Yoshida has a 1999gn page . ... Kopernik 's M61 and supernova 1999gn page . ... vsnet-alert 3835 ] SN 1999gn in NGC 4303 = Messier 61 . ...