... HSP photometric accuracies are strongly dependent on the observational setup and observing conditions, such as spacecraft jitter. Absolute photometry can be done only with a one sigma limiting accuracy of approximately 5%, but relative photometry is possible with an accuracy of 1-2%. Estimated HSP Calibration Accuracies . Absolute Timing . ... Relative Timing . ... 1991 through summer 1993 monotonic decrease, . ... Absolute photometry . ... 5% (one sigma) . ... Relative photometry . ...

... The BL Lac objects found within DXRBS fall mostly in the range . ... A large fraction of the BL Lacs so far in our sample are at L X / L R < 10 -6.5 , the region of Figure 6 populated by LBLs. In this region of parameter space (to the left of the left-most dashed line in Figure 6), DXRBS includes objects up to two orders of magnitude fainter than the 1 Jy survey. ... For comparison, we have plotted the values for members of these three ROSAT-based surveys (DXRBS, HQS/RASS and RC) in Figure 7. ...

The overall efficiency (including atmospheric transmission, reflectivity of the telescope mirrors and overall efficiency of the optics and of the detector) for broad-band imaging should be about 25% in H and K, and about 15% in J. The main noise source for both broad- and narrow-band imaging should be the photon noise associated to the background+source flux. ... Flat fielding (and possibly background subtraction) might increase the noise by a factor 2 ? ...

... 17mar10: allowable za range, tiedown tensions for mar10 . ... We have at least 20 kips of td tension on each corner . ... A constraint for our pointing model is that the carriage house is at stow (8.835 degrees). ... Bottom: With the dome at za=8.4, the carriage house can travel from 0 to 20 degrees za and stay within the 3000 kip-feet limit. ... run the dome from 6 to 10 degrees za with the carriage house at stow (8.835). run the ch from 0 to 20 degrees with the dome at 8.4 degrees za. ... dome . ...

. Album : asv-album :: Technical photos :: a80tests ::Limited dynamic range demostrations . Up . IMG 0308 . IMG 0309 . IMG 0396 . IMG 0397 . IMG 0398 . IMG 0399 . Album created by album script a script by David Ljung on Mon Jan 19 20:23:14 2015 .

... The program will propose reasonable default choices, and will provide some approximate estimates of the magnitudes where photon noise becomes excessive, and where photon and scintillation noise are comparable. ... Table shows what a typical crossover table looks like. ... We would generally prefer to have the extinction measurements limited only by scintillation noise, so the initial faint limit for extinction stars is set 1.5 magnitudes brighter than the brightest of the crossover values. ...

... ATNF Home . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Astrophysics graduate student programs . ... Australian Square Kilometre Array Pathfinder . Murchison Radio-astronomy Observatory . ... Parkes radio telescope . Australia Telescope Compact Array . Mopra radio telescope . ... In general it is expected that the overall sensitivity limit will be imposed by the readout noise from the science detector, even given that coherent `blind' integration is possible. ...

... Bojan Nikolic web pages (r. 329) . ... Using high-resolution three-dimensional realisations of turbulent fields, we investigate the limits on achievable performance of atmospheric phase correction using water-vapour radiometers arising from following effects: the incoherent measurement of power from water by the radiometers (in contrast to coherent detection of the astronomical signal); the different tapers of the response patterns of the astronomical and radiometer receivers; and, the ...

... Using a simple 2-D Gaussian Point Spread Function (PSF) on a constant (flat) sky background, I derive a theoretical photometric and astrometric performance model for analytical and digital PSF-fitting stellar photometry. ... The photometric performance is maximized when either the effective background area or the effective-background-level measurement error is minimized. ... An important, but frequently ignored, noise source is the uncertainty of the measurement of the effective background level ( )...

... ARC 3.5m | Weather Closure Conditions . The enclosure will be closed by the Observing Specialist under the following conditions. ... This policy will be consulted whenever there are questions or disagreements concerning closure of the APO 3.5-meter telescope due to hazardous conditions or situations, at times when telescope operations are being overseen by an APO Observing Specialist. ... the on-duty Observing Specialist has full responsibility, and sole authority, to make this decision. ...

... GCN 8471 | ... TITLE: GCN CIRCULAR NUMBER: 8516 SUBJECT: GRB 081102: MASTER refind and final results DATE: 08/11/11 15:50:10 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs E. Gorbovskoy, V. Lipunov, V.Kornilov, A.Belinski, N.Shatskiy, N.Tyurina, D.Kuvshinov, P.Balanutsa Sternberg Astronomical Institute, Moscow State University A. Tlatov, A.Parkhomenko Kislovodsk Solar Station of the Pulkovo Observatory V.Krushinski, I.Zalognikh Ural State GCN Circ 8470, Lipunov et al., ...

. Next: Multiple Data Sets Up: *fit* - Fit Data Previous: Two-Temperature Raymond Model . The energy range covered by the default channels depends on the instrument gain. To limit the fit to channels 7 to 30, specify the file with observed spectrum as: rp90[7:30] # will fit as before but using PSPC channels 7 to 30 # in the 34 binning scheme . rsdc@cfa.harvard.edu . 1998-06-10

... Design of Imaging Optics . Analyzing Optics . ... The high resolution near infrared camera (CONICA) for the first VLT unit telescope is under development. It serves as a multi-mode instrument for the wavelength region between 1.0 and 5.0 microns, providing diffraction-limited spatial resolution when combined with the adaptive optic system NAOS of the VLT (Rosset et al. ... VLT instrumentation, ALADDIN InSb detector, NIR imaging, NIR spectroscopy, re-imaging optics, IR optics . ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... Radio luminosity - spectral type plot for all ultracool dwarfs observed at 4.9 GHz. ... Whilst no radio emission was detected from any of the targets, significant upper limits were placed on the radio luminosities that are below the luminosities of previously detected ultracool dwarfs. Combining our results with those from the literature gives a detection rate for dwarfs in the spectral range M7 тАУ L3.5 of тИ® 9%. ...

... GSAOI Home . ... Science . ... This project aims to probe the main sequence mass function and substellar limit in old metal-poor Galactic globular clusters. ... Deep JHK images reaching the end of the population-II main sequence are required for several globular clusters. ... Images of the old Galactic globular cluster NGC 6121 in the visible ( left panels ) and near-infrared ( right panels ) take from the ground ( top panels ) and with the Hubble Space Telescope ( bottom panels ). ...

... At the Limit of Diffraction . ... Credit Copyright: Yuri Beletsky ( Las Campanas Observatory , Carnegie Institution ) Explanation: Did you ever want to just look through the eyepiece of a large telescope in space ? If you could, you would see a sharp view that was diffraction limited . ... Still, in this working earth-based snapshot a new active adaptive optics system (MagAO) is being used to cancel out the atmospheric blurring in a visual observation of famous double star system Alpha Centauri . ...

Astronomy Binoculars - The Skies The Limit . ... Binoculars for astronomy are usually powerful. ... If you are buying a hand held binocular to look at the skies, make sure it isn't so heavy that you can't hold it for long periods of time. ... You should also visit some astronomy web sites or binocular reviews and see what the astronomy enthusiast are using. ... Remember that binoculars for astronomy tend to be very powerful and they don't usually have a huge field of view. ... www.astronomy.net . ...

... S.P. KOROLEV ROCKET AND SPACE CORPORATION ENERGIA . ... OAO RSC "Energia" . ... Company's History . ... ISS Russian Segment . ... Build an operational model of neutron background environment on the station; . ... Correlation data on radiation environment parameters outside the Service Module of the ISS RS obtained through calculation with the results of measurements made by science hardware BTN-M1 and results of other Russian and international experiments; . ... 2015 JSC "S.P. Korolev RSC "Energia" ...

The beam pattern and the polarization characteristics . of the radio telescope RATAN-600 . The Mueller matrix elements was computed via formulas [1]: . ... The BP were computed by the aperture method, proceeding from the fild distribution in the aperture of the primary mirror. The components of the main and cross-polarization components of the electric field in the vertical aperture of the primary mirror was computed in Frenel diffraction approximation. ...

... These are just the bare bones--just three basic ideas and rules for handling relations ("equations") involving unknown quantities whose values you are trying to find. In most calculations you try to find a number . ... To get a solution, one must replace the given equation (or equations) with others, containing the same information but cleaner in appearance. ... If you have an equation and modify both its sides in exactly the same way, what you get is also a valid equation. ...