... December 21, 1997 . ... Advantages are briefly discussed of gaining in spectral resolution, which is accompanied by losses in signal level, as compared with the attempts to improve the accuracy of measurement of line parameters by means of rising the S/N ratio alone with increasing the exposure time. To partially solve the problem of observations of faint objects at the BTA a new design echelle spectrometer is proposed. high resolution spectroscopy . ...

Direct Electron Imaging Using Back Thinned CCDs . ... A proximity focused Gen III image intensifier has been built using a back illuminated 512 x 512 CCD in place of the phosphor screen. Signal to noise, spatial resolution, minimum resolvable signal and life are discussed. ... Very low light level imaging is driven by the need for high quantum efficiency detection of single photons at the highest possible speed and the highest spatial resolution. ...

... ESO Science Newsletter December 2015 . 17 Dec 2015 . ... This newsletter is a summary of recent ESO Science Announcement items. Follow the links or visit ESO Science Announcements to read more. ... Read more . ... The allocation of ESO telescope time for Period 97 (1 April БЂ“ 30 September 2016) is expected to be emailed in the week beginning 21 December 2015. ... ESO Workshop, ESO Headquarters, Garching, Germany, 27 June БЂ“ 1 July, 2016 . ... Joint ESO, ALMA, NAOJ, NRAO Workshop. ...

... I present results from several seasons of photometric observations of X--ray sources in the Orion OB1a and OB1b star formation regions. The initial goal was to measure the rotational periods of several dozen pre--main sequence (PMS) stars. ... Infrared and optical data confirm that 90% of the X--ray sources are PMS and about 10% of the PMS stars may have disks. ... I find rotation periods for five stars at confidence of greater than 99.9/ greater than 99/ at much lower confidence. ...

Next: Accretion Disks with Up: StarsStellar Populations, Previous: Spectroscopic Analysis of . ... We present and discuss spatially resolved spectra of the accretion disk and the gas stream region as a function of distance from disk center, the spectrum of the uneclipsed light, and the radial temperature distribution in the ultraviolet. Keywords: Accretion disks, Cataclysmic variables . ... In this paper we report on the HST spectral mapping of the nova-like UX UMa. ...

Position Switching Separation Tolerance with Arecibo in L-Band Travis McIntyre The University of New Mexico July 2010 Revised December 2013 Abstract The blocked telescope aperture at Arecibo creates standing waves in the bandpass around 1MHz. ... Test observations with Arecibo in L-Band show that position switching effectively removes standing waves for separations of one half FWHM or less. Standing waves remain for separations of one FWHM, increasing the rms of the baseline by 20%. ...

... The best seen visible auroral forms are due to precipitating electrons. ... As typical for diffuse aurora, the proton precipitation is confined to be most often on the equatorward part of the oval. ... When proton aurora occurs at the same local time sector as pulsating (electron) aurora, they are typically located northward from pulsations (e.g., Creutzberg et al., ... Eather, R. H., Auroral proton precipitation and hydrogen emissions, Rev. Geophys., ... Geophys., ... Res., ... 87 , 2481, 1982. ...

SITE 2010 Comprehensive Characterization of Astronomical Sites Kislovodsk, Russia, 49 October 2010 Conference Summary Marc S. Sarazin*a a European Southern Observatory, Garching, Germany Abstract The main topics discussed during the Site 2010 conference are outlined and the outcome is described. Keywords: Astronomical Site testing, precipitable water vapor, atmospheric turbulence, cloudiness, seeing 1. ... Site surveys for National observatory projects in China, India, and Iran benefit from this. ...

... Several knots of radio emission in the jets were identified and their motion could be followed