... 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 . ...

... 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 . ...

This is the homepage of Andrew Fruchter, an astronomer on the staff of the Space Telescope Science Institute . ... Here you can look at an HST images of the optical counterparts of gamma-ray bursts and their host galaxies. ... Therefore, substantial information on the fine scale structure of objects can be obtained by offsetting the pointing of the telescope between exposures and then combining these "dithered" exposures into a single image. ...

XMM-Newton Calibration - intro · Briefly review the ground calibration · Highlight the unique calibration issues of XMMNewton · Review the life-cycle of calibration observations, analysis, and ingestion into SAS · The publication of calibration data and ensuring correct sets used in SAS XMM-Newton David Lumb -- No need to calibrate XMM on-ground ­ AXAF will be calibrated to 1% so just calibrate to them!" ... XMM-Newton David Lumb --XMM-SOC 8 ...

... The experience of determination of the link between radio sources and dynamical reference frames is presented. To obtain this connection we used a series of very long baseline interferometry (VLBI) observations of the spacecraft Phobos-2 and angularly nearby quasars. ... The dynamical reference frame is determined by equator and equinox of these ephemerides. ... References . ... The relative orientation of the radio and dynamical reference frames can be described by a sequence of three rotations . ...

The database contains references to the papers, data files and links to the Internet resources related to measurements and calculations of the optical constants in the wavelength interval from X-rays to radio domain. ... References to some useful books and reviews on the subject (e.g. the classical handbooks edited by E.D.Palik) and links to Internet collections of optical constants and personal WWW pages with related software were also placed in the database. You have arrived at our welcome page. ...

... Archives . ... If you do not mind the time predictor, it is hard to believe that this is a light curve, time dependent data. ... It?s hard to say this data set is designed for time series analysis apart from the complication in statistical inference due to measurement errors. How to design the statistical study with measurement errors, huge gaps in time, and unequal time intervals is complex and unexplored. ... The following is R output without measurement errors. ... Chandra Blog . ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... Lower panel: The ME spot map of the star in orthographic projection, showing the disc of the star as it would be seen by an observer on the Earth at the labelled rotation phases (see the text). ... We carried out high-resolution spectroscopy and BV(I)C photometric monitoring of the two fastest late-type rotators in the nearby Pictoris moving group, HD 199143 (F7V) and CDтИТ64 1208 (K7V). ...

... We publish 16 Doppler imaging temperature maps for the years 1994-2002 of the active RS CVn star II Peg. ... Through Doppler imaging we want to study the spot evolution of the star and in particular compare this with previous results showing a cyclic spot behaviour and persistent active longitudes. ... The derived temperature maps are quite similar to the ones obtained earlier with a different methods, the main differences occurring in the spot latitudes and relative strength of the spot structures....

Subject of Celestial Mechanics. ... Differential Absolute Coordinates Equations of the Problem. ... General Integral of Non-Perturbed Motion. ... General Equation of Non-Perturbed Orbit. ... Other Integration Methods of Non-Perturbed Motion Differential Equations; Bine Equation for Case of Non-Perturbed Motion. ... Ellipsical Motion, Kepler Equation. ... Motion Differential Equations in Absolute Coordinates. ... Equation of System of Bodies Motion in Barycentric Coordinates, in Relative Coordinates. ...

Start Data Acquisition - Selected Wavelengths - 22/Apr/2014 16:28:09.666 Observation Type - Grid Images - 22/Apr/2014 16:28:09.679 22/Apr/2014 16:28:11.717 Begin Iteration #1 of 2 - Number of Frames : 17 - 22/Apr/2014 16:28:11.729 Filter : 6563 (Position 3) | ... Acquisition Time : 22/Apr/2014 16:28:11.851 | ... ExpTime (sec) : 0.030 | Stokes : I Filter : 6563 (Position 3) | ... Stokes : I Begin Iteration #2 of 2 - Number of Frames : 17 - 22/Apr/2014 16:28:14.440 Filter : 6563 (Position 3) | ...

... In this case, because polarimetry is not currently possible with the 3-mm system, only task mfcal is needed to perform bandpass and antenna calibration. ... This section outlines an alternative calibration approach exploiting the dual frequency bands of the ATCA. ... Unlike the approach of Chapter 11 , the approach described here does not split the data into separate single source, single frequency files before calibration. ... Input multi-source, dual-band dataset. select=source(1921-293) . ...

Next: Chemical abundances Up: HS 0822+3542 - a Previous: H I 21 cm . The main parameters of HS 0822+3542, along with those of the two earlier known local candidate young galaxies, are presented in Table 1 . The distances to all three galaxies for the sake of homogeneity are derived from the radial velocities. ... However, such distance estimates for two galaxies, HS 0822+3542 and I Zw 18 with small radial velocities are rather uncertain. ... The same relates to HS 0822+3542. ...

Next: ST-ECF Grism Spectrum Software Up: NICMOS Data Calibration and Previous: Photometric Performance of NICMOS . ... Wavelength Calibration of NICMOS Grisms . ... This article describes the wavelength and throughput calibration of the grisms and discusses the photometric performance of the NICMOS grism mode. ... The resolution of the first order spectra on all grisms is about 200 per pixel. ... Spectra were extracted for bright objects with both first and second order spectra on single grism images. ...

Pulkovo Database of Observations of Visual Double Stars . ... Catalog of relative positions of visual double stars, based on photographic observations performed since 1960 in Pulkovo on the 26-inch refractor (A.A.Kiselev, O.A.Kalinichenko, O.V.Kiyaeva, N.A.Shakht, L.G.Romanenko, I.S.Izmailov, O.P.Bykov, K.L.Maslennikov, E.A.Grosheva, D.L.Gorshanov), 2010 . ... Enter either ADS or WDS number. Click here to display full list of visual double stars observed at Pulkovo. ADS . ...

The examples of the errors. ... Observations with ordinary values of the "Mean error of single observation" Obj Code DT RA (O-C) DEC (O-C) mag z h m s " ° ' " " ° 3907 761 1998 08 24.383673 3 17 44.739 0.28 +30 46 00.84 -0.08 15.8 18 3907 761 1998 08 24.409133 3 17 46.152 0.28 +30 46 10.85 0.12 15.8 11 3907 761 1998 08 25.392523 3 18 40.107 0.33 +30 52 27.69 0.04 15.4 15 Total mean value of 3 observations 0.297±0.017 0.027±0.058 Mean error of single observation 0.029 0.101 COMMENT. ...

RELATIVE SUNSPOT NUMBERS Description of Data from SGD Explanation of Data Reports: Relative Sunspot Numbers -- The relative sunspot number is an index of the activity of the entire visible disk of the Sun. ... The provisional daily Zurich relative sunspot numbers, Rz, were based upon observations made at Zurich and its two branch stations in Arosa and Locarno and communicated by M. Waldmeier of the Swiss Federal Observatory. ... This indicates the uncertainty above and below the predicted number. ...

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