... Spectral Filters . Quantum Efficiency and Exposure Limits . ... Which Instrument to Use: WFPC2, ACS, NICMOS, or STIS? Comparison of WFPC2 and ACS . Comparison of WFPC2 and NICMOS . Comparison of WFPC2 and STIS . History of WFPC2 . ... WFPC2 . ... What's New in Version 5.0 for Cycle 10 . ... WFPC2 Handbook on the WWW . ... Calibration Channel . ... LRF Photometric Calibration . ... Sources of Dark Current . ... Calibration Plan Summary . Cycle 4 Calibration Plan . ...

... Instrument tuning )! ... Specific calibrations have been performed recently Standardized high energy Crab spectrum would be very useful JEM-X calibration JEM-X is affected by some instabilities which affect software and calibrations: microstrip erosion ( decreased HV and S/N) microstrip ions diffuse into glass plate ( HV adjustments) gain variation ( electronic efficiency to be determined on short time scales) memory effect on microstrips transient hot spots Observations are ...

Next: Optimization of spectroscopic observations Up: On the problem of Previous: On the problem of . In comparison with spectroscopy of extended extragalactic objects, the task of observing stars with a high spectral resolution is traditionally given lower priority. ... A ``natural'' response of some researchers of stars and starlike objects is preferential use of low and moderate spectral resolution techniques, where one succeeds in minimizing losses at the spectrograph input. ...

... 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 ( )...

... The J, H and K bands are characterized by a bright background, such a background is mainly due to the emission of atmospheric lines and of thermal radiation. ... If the source cover a large fraction of the slit, spectra off-source must be observed to adequately sample the sky background. ... The on chip integration time (time spent in each position of the slit) must not exceed 40 seconds in J and H bands and 60 seconds in K band. ... We suggest a sequence of 10 for each elementary integration time. ...

... Calculated exposure times do not take into account instrument and telescope overheads. ... The reference area for the S/N is circular with a radius equal to FWHM of the Image Quality PSF at the airmass and wavelength of observation. ... begin{equation} \mathit{FWHM}_{\text{IQ}} = \sqrt{\mathit{FWHM}_{\text{atm}}^2(\mathit{s},x,\lambda)+\mathit{FWHM}_{\text{tel}}^2(\mathit{D},\lambda)+\mathit{FWHM}_{\text{ins}}^2(\lambda)} \end{equation} } \) . ... The Exposure Time is the product of DIT and NDIT . ...

Home About Meade Product Information Dealer Locator Customer Support Investor Relations Dealer Support Employment Opportunities Site Map . Meade Instruments Corporation . ... Meade Binocular Limited Warranty . ... Meade will repair or replace the product, or part thereof, found upon inspection by Meade to be defective, provided the defective part or product is returned to Meade, freight prepaid, with proof of purchase. ... This warranty supersedes all previous Meade binocular warranties. ...

... Main page News People . ASA . Master . Master net Homepage . ... MASTER . ... About Space Monitoring Laboratory, scientific directions, instruments, contacts . ... Latest news and news archive . ... 21.05.2011 . ... All news ...

DISCLAIMER: The larger the aperture, the more light a telescope will gather and the fainter the object you can see. Here is a range of magnitudes you might expect to see. Given excellent sky conditions and good optics, a well trained eye can sometimes add up to 0.8 magnitude to these values. Limiting Magnitude depends on much more than the instruments aperture. ... One formula is for aperture in inches the other is for aperture in millimeters. ... Aperture (inches) . ... 15.2 . ...

... Time calculated from Fermi GBM Trigger Time = 14:12:08.67 ( Connaughton, GCN 9230 ). 1% coincident with our start zero image time. 3x3 degrees around Swift XRT position . ... SUBJECT: GRB 090424 : MASTER-Net prompt optical limit DATE: 09/04/25 20:29:42 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs E. Gorbovskoy, V. Lipunov, V.Kornilov, A.Belinski ... Our observations results: ---------------------------------------------------------------------- Fermi GRB Trigg.* ...

In calculating the NIFS sensitivity, we adopt a read noise of 5 e - , a dark current of 0.01 e - s -1 pix -1 , and a maximum exposure time of 3600 s. Grating . ... e/pix) . ... OH Cont. (e/pix) . ... NIFS should achieve signal-to-noise ratios of ~ 10 per spectral pixel in a 0.1" 0.1" aperture for single 1800 s exposures on uniform, extended, continuum sources with surface brightnesses of J = 15.4, J = 15.0, H = 14.8, and K = 13.5 mag arcsec -2 using the Z , J , H , and K gratings, respectively. ...

... Observations have received at the telescope AT-64 of the Crimean Astrophysical Observatory . GRB . ... RA(2000): 11h 45m 10.54s . DEC(2000): 17o 24' 34.44" . ... Filter: none . ... Date, time (UT) . Exposure . ... 2000.07.29 18:21:52 . 30 sec . ... RA(2000): 19h 58m 19.61s . DEC(2000): 23o 32' 35.15" . ... 120 sec . ... DEC(2000): 6o 20' 47.07" . ... 240 sec . ... DEC(2000): 51o 46' 34.93" . ... DEC(2000): -13o 04' 30" . ... DEC(2000): +55o 18' 25.0" . ... 2000-11-09T16:03:19 . ...

GRIZLI Science Performance Goals Includes also some performance goals for telescope and software 16 October 2011 A. Instrument specs 1. Delivered image quality, in each filter, across entire FOV Goal: 0.5" FWHM, with well-behaved PSF, at high altitude (low airmass) 2. Limiting magnitude Goal: 26th mag in griz gives S/N=10 in 3 min exposure sky-limited in all filters with no moon 3. ... Fringing Goals: (for 3 min exposure) - less than 1% in i - less than 5% in z 8. ...

Pulsar Stability (and ) Joris Verbiest Swinburne University ATNF Matthew Bailes (Swin) Richard Manchester (ATNF) George Hobbs (ATNF) William Coles (UCSD) Andrea Lommen (F M) *: GWB = Gravitational Wave Background Outline · High precision timing of MSPs* · Long-term timing stability · Simple GWB limit technique · Conclusions *: MSP = Milli-Second Pulsar Quick Basics of Pulsar ... Pulsar Spectrum GWB PSR J0437-4715 Stability: Examples: 1713 PSR J1713+0747: 362 ns over 14 yrs ...

... Parallel to HIPASS: o HIDEEP: "The HI equivalent of the Hubble Deep Field" ­ (9000s per beam) HIDEEP: The Basics ! ... selection limits: o peak flux and velocity width limited o limits are 9.6 mJy and 4 ch = 52.8 km/s o completeness limit at ~18 mJy 5 optim.smooth limit 3 peak flux limit HIDEEP: Optical Follow-Up ! ... Galaxies in HIDEEP are more gas-rich observed corrected HIDEEP: Column Densities - Theory TB = ! ... There don't appear to be any low-column density galaxies in HIDEEP ! ...

. 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

Next: Order Extraction Up: Background Definition Previous: Background estimate by . ... The sky background component can be measured in spectra taken with an extended slit using the two commands DEFINE/SKY and EXTRACT/SKY . ... The command EXTRACT/ECHELLE performs an average extraction of the sky background using these offsets, optionally fiters for cosmics, and provides an extracted spectrum in a format similar to the one resulting from EXTRACT/ECHELLE . ...

... Flux density at 1 GHz (/Jy): 19 . ... Notes: This is the remnant of the SN of AD 1006. ... Optical: Filaments to the NW, with broad H component. ... Point sources: The background Schweizer Middleditch star is near the middle of the remnant. ... van den Bergh 1976, ApJ, 208, L17. Optical observations. ADS . ... X-ray spectroscopy. ... Schweizer & Middleditch 1980, ApJ, 241, 1039. ... Optical spectroscopy of the Schweizer Middleditch star. ... Optical spectroscopy. ... 2013, A&A, 552, A9. ...

Surface-layer turbulence measurements with lunar scintillometer Idea of the method Hardware & software Campaigns & results New horizons Andrei Tokovinin NOAO/CTIO Kislovodsk Oct. 2010 1 Turbulence measurement from scintillation of extended sources Moon's angular diameter =0.5 deg Correlated scintillation for b > z z=10m b=0.1m z=100m b=1m z=10km b=100m BI(b) = W(b,z) Cn2(z)dz Weighting functions zW(z) for b=0...0.4m and d=1cm 2 Kislovodsk Oct. ... 2010 12 Paranal: October 14, 2008 Kislovodsk Oct. ...

Peremennye Zvezdy", . ... Star Name: . ... During observations of a field in Perseus, we discovered a transient event. ... A total of 5 images with 5-minute exposures were obtained on JD 2455538. ... The combined image is shown under the light curve (top right panel). ... At the transient's position, an extremely faint star-like image is visible, marked as "Var"; its magnitude is approximately 13 m . ... Light Curve . The light curve of the transient and four images of the region around it. ...