... Let us first find out which way -- rise in spectral resolution with some loss in the S/N ratio or increase in the S/N ratio with a fixed spectral resolution -- is better for the purpose of reduction of equivalent width determination errors. ... N -- number of counts for 1 ? ... line equivalent width, . ... Thus if the spectral resolution is managed to be increased (i.e. to decrease )without loss in the number of counts falling at 1 ?, the equivalent width measurement error is then proportional to . ...

... Time-series of high resolution spectra have been obtained during three nights and several important events were detected. Observations contained several chromospheric lines, allowing to investigate simultaneously the response of the chromosphere at different heights. A detailed analysis of the H alpha line behaviour, in particular, has revealed prominece clouds and plage-like regions in this star. ... Promience clouds are seen to lie below the co-rotation radius. ...

... AGES Precursor Observations · Targeted the M74 ( NGC 628) group · Noise falls as t (to 200s) AGES Precursor Observations · Targeted the M74 ( NGC 628) group · Noise falls as t (to 200s) AGES Precursor Observations · Targeted the M74 ( NGC 628) group · Noise falls as t (to 200s) · Detected 5 galaxies in the group KDG 010 dw0137+1540 UGC 1171 AGES Precursor ...

Solar High Resolution Studies . ... Solar Group . ... High Resolution Studies . Small Scale Activity . ... High resolution observations at different heights in the solar atmosphere have emphasized that there is no such thing as a "quiet" Sun (e.g. Schrijver et al., ... This, and the temporal coincidence of other signatures, supports the idea that microflares are indeed just miniature flares, but that one needs a very high resolution in order to observe them (Cauzzi et al., 2003, in preparation) . ...

... The remote planet Pluto and its moon Charon orbit the Sun at a mean distance of almost 6,000 million kilometres, or nearly fourty times farther out than the Earth. During a recent investigation by an international group of astronomers [1], the best picture ever of Pluto and Charon [2] was secured with the European Space Agency's Faint Object Camera at the Hubble Space Telescope (HST). ... The new HST image was taken when Charon was near its maximum elongation from Pluto (0.9 arcseconds). ...

RATAN-600 OBSERVATIONS OF MICROWAVE STRUCTURE OF THE QUIET SUN T.I. Kaltman, V.M. Bogo d, A.N. Korzhavin, S.Kh. ... A small-scaled structure with the size of 20-40 arc sec is regularly observed with RATAN-600 one-dimensional observations. ... The daily monitoring with RATAN-600 observations provides p ossibilities to regularly estimate a state of the quiet Sun by emission characteristics of microwave small-scaled structure and to trace rises of new centers of activities. ...

To main of Laboratory . The research work and design of optical and optical-electronic devices are carries out by laboratory staff: . ... Lens: . ... In the layout 1 prism systems perform functions of dispersive element, corrector of aberrations, optical reducer. ... Spectral range 200 - 400 nm; . ... Back Forward . ... The main corrector's function are compensation of field aberrations of the main spherical mirror of a telescope (diameter of 600 mm, f'=1200 mm) and increase aperture ratio. ...

... All the images except two are in the Si-5 filter, which has a central wavelength of 11.68 microns and a width of 1.01 microns. This filter shows only dust emission, and excludes the emission lines that PNs have in the 10 micron region of the spectrum. ... The emission from NGC 6210 in the 11.7 micron filter is even fainter than that for PN G058.3-10.9, barely within the sensitivity limit of the Gemini telescope. ... The Si-5 filter image looks completely different than the N-band image. ...

... 2001 July 25 . Hot Gas Halo Detected Around Galaxy NGC 4631 . ... Explanation: Is our Milky Way Galaxy surrounded by a halo of hot gas? ... Since NGC 4631 is similar to the Milky Way , this observation indicates that our own Galaxy is indeed surrounded by a halo of hot X-ray emitting gas, although we are too close to clearly differentiate it from more nearby extended X-ray sources. The clusters of massive stars probably heat the halo gas. ... About APOD | ...

... In combining the data, it is assumed that the low resolution image better represents the short spacing data, whereas the high resolution best represents the fine structure. ... Key: out The output image. ... Key: factor The flux calibration factor. ... In practise, the calibration may not be perfect, and an extra calibration factor will be required to align the flux scales. "factor" gives the factor to scale the low resolution image to put it on the same flux scale as the high resolution image. ...

... A radio galaxy is a galaxy that emits an unusually big amount of energy at radio wavelengths. ... Inside of each galaxy with an active nucleus (radio galaxies are among them) there must be a system of a "central machine" responsible for the colossal amount of the emitted energy from radio to gamma ranges. ... Sometimes a radio source in an active galaxy may flare again if the needed conditions appear (a new portion of matter would fall into the furnace of the "central machine"). ...

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. ...

SAS home . ... List of SAS threads . OM data processing from A to Z is performed by two "chains": omichain and omfchain , for image and fast mode data respectively. ... Then a source detection algorithm is used to identify the sources present in the image. ... A final source list is obtained from all exposures and filters. ... If the user has PPS products from the processing of his/her observation, or from the XSA, then the first thing to do is to overlay the image source list onto the sky image. ...

... Contacts: Evgeny A. Loupian, Dr. Sci., e-mail: evgeny@smis.iki.rssi.ru Sergey A. Bartalev, Dr. Sci., e-mail: bartalev@smis.iki.rssi.ru Web interface for burnt area mapping using Landsat data Stellar Tracker In 2013 IKI RAN together with the NPK "Electrooptics" completed the phase of the five-year research on studying the ways to build a stellar inertial navigation system (SINS) for aviation applications. ... Fig. 1 shows the SINS layout created on the basis of the astronomical camera. ... Fig.1. ...

Next: A Universal Diagram for Up: ``Ecology'' of Magnetic Rotators Previous: The Corotation Radius . The interaction of a magnetic rotator with the surrounding plasma to a large extent depends on the relation between the four characteristic radii: the stopping radius, , the gravitational capture radius,   , the light cylinder radius,   , and the corotation radius,   . ... Hence, the classification of the interaction regimes may well mean the classification of magnetic rotators. ...

... Other Characteristics of the Sun: Variability of Rotation, Magnetism, Chemical Structure, Planetary System. ... Methods of Solar Magnetic Fields Measuring: Visual, Photografic, Photoelectric. ... Empiric Datas of Magnetic Fields in Photosphere, Chromosphere and Corona. ... Characteristics of Magnetic Field in Balanced Force Tubes by Potential and Forceless Field. ... Phenomenons in Active Region (Magnetic Field, Spots, Torches, Solar Prominences, Flares, Discharges. ... Magnetic Fields in Flares. ...

... Director of the RAS ISR . RAS Academician . ... Astrophysics module Kvant of the orbital complex Mir launched in 1987 contains the largest on the station complex of the scientific equipment named the orbital observatory Roentgen. Observatory Roentgen consists of 4 X-ray telescopes, jointly exceeding the range of energies from 2 to 800 keV. ... Among the most significant results that were received in the observatory Roentgen are: . ... measurement of the periods of 9 X-ray pulsars; . ...

... The stars examined here were primarily culled from two lists of X--ray sources in Orion. ... The second region is two degrees in extent east--west and ten degrees north--south with Orionis being near the northern edge. ... In the end, two main regions were chosen for monitoring: stars near Orionis and stars northwest of the belt of Orion. ... The PSPC identified 22 sources within 15 of Orionis in addition to the sources listed in Table 1 , giving a total of 85 X--ray sources in the Orionis region. ...

To appear in "Fourth Workshop on Robotic Autonomous Observatories (2015)"RevMexAA(SC) METEOR OBSERVATIONS WITH MINI-MEGATORTORA WIDE-FIELD MONITORING SYSTEM S. Karpov, 1, 3 N. Orekhova2 G. Beskin, 1, 3 A. Biryukov3,4 S. Bondar,2 E. Ivanov,2 E. Katkova,2 A. Perkov, and V. Sasyuk3 RESUMEN 2 Favor de prop orcionar un resumen en espanol. ... The faintest detected meteors has the peak brightness about 10 mag, while the ma jority - from 4 to 8 mag. ... 2010; Karpov et al. 2013; Beskin et al. ...

... Comet Tutorial . ... On July 1, 1993 an image was taken with the Hubble Space Telescope (HST) that clearly shows at least 15 individual fragments in one image frame of the train. ... This made an accurate orbit (or orbits) difficult to determine; however, after numerous observations of the comet, astronmers determined that the comet had passed within 96,000 kilometers (60,000 miles) of the center of Jupiter or 25,000 kilometers (16,000 miles) from the cloud tops during the July 8, 1992, approach. ...