Next: CCD data Up: Special problems Previous: Marginal nights . If the program complains that you have negative intensities, this is usually due to misidentifying star observations as sky. ... Another problem with sky occurs when the program cannot find a suitable sky observation to subtract from a star datum. ... Finally, as the sky-modelling algorithm does not try to model twilight, it uses the ``nearest-neighbor'' method to correct star observations made during twilight for sky. ...

... Team . ... The main goal of observations of GRB host galaxies is accumulation of statistics of their spectroscopic and photometric properties. ... The Hubble diagram for 22 GRB host galaxies with known magnitudes and redshifts (GRB 970228, GRB 970508, GRB 970828, GRB 971214, GRB 980613, GRB 980703, GRB 990123, GRB 990510, GRB 990712, GRB 9912008, GRB 991216, GRB 000131, GRB 000210, GRB 000301C, GRB 000418, GRB 000911, GRB 000926, GRB 001109, GRB 010222, GRB 010921, GRB 011121 and GRB011211). ... 600...

... Meta Index / Home Page / Errors . ... warning . ... For instance, if the PROPOSAL information record is missing the user can add a fake one to the SOSF without this having any effect on the data reduction. corrective action: Continue. ... For a certain exposure in the ODF one of the parameters was not found in the housekeeping data. ... RGS, EPN, OM : the current exposure is found to contain more than one distinct calibration mode. corrective action: In the summary file: MODE = UNDEFINED . ... error...

Next: Ionospheric Corrections in AIPS++ . ... Previous: AIRY: Astronomical Image Restoration in interferometrY . ... Calculate residual images for all facets (using 2-D transforms). Partially deconvolve individual facets and update the image model for each facet. ... The image in Figure 1 was made using the AIPS++ widefield algorithm with 225 facets. ... In calculating the residual image the residual visibility re-projection for the different facets can be estimated independently. ...

... Please note the following problems and workarounds: . ... Arrow keys . Arrow keys are used in SAOtng to move the mouse or markers. ... Unfortunately, error messages are generated if both sets are defined in the SAOtng code but are not supported by X. To get around this problem, we have added the -kbprefix command switch (and the SAOTNG_KBPREFIX environment variable) to SAOtng. This switch allows you to specify which arrow keys you want to use (assuming your version of X supports both). ...

... To be read in conjunction with Section 4.11 of the WFPC2 Instrument Handbook , -Version 4.0. ... 1 The second study found evidence that CTE loss for faint stars has increased with time (Whitmore, 1998). The primary observational consequence of CTE loss is that a point source at the top of the chip appears to be fainter than if observed at the bottom of the chip, due to the loss of electrons as the star is read out down the chip (see Figure 1 ). ... Last updated: 06/16/98 10:38:00 . ...

... The effect of the bug has been that timestamps indicating when data was taken (FITS-header keyword CRVAL5) may be off by one second. ... DETAILED DESCRIPTION -------------------- AFFECTED KEYWORD: The affected keyword is: CRVAL5 (time stamp indicating start time of subscan) Synchronisation errors between the 1PPS pulses and the NTP-controlled system clocks have frequently caused the timestamps indicating the start of each subscan (CRVAL5) to be off by one second. ... That problem has also been fixed...

... Contact A Problem of an estimation of accuracy of the asteroid CCD observations . The Minor Planet Center supported by the Interntional Astronomical Union is the main office for keeping observational data of the small Solar System bodies and their investigations. ... At Pulkovo Observatory we are estimating an accuracy of the CCD asteroid observations obtained by amateurs and professional astronomers all over the World using the MPC database. ...

... I would several points which we faced during our everysolved for better quality of individual ACs' and EOP products · There are two main EOP products provided by two IERS Product Centers on Earth Orientation (Earth Orientation Center (EOC) and Rapid Service/ Prediction Center (RSPC)). ... However, the latter is not provided by the IERS. ... ITRF · Using ITRF in computation of EOP series produced by various ACs seems to be a necessary condition to provide the consistency between the IERS products. ...

ALMA | ... Phase Correction Algorithms | ... On this page, we describe what the phase correction algorithms set out to do and the framework we have developed to optimally use all of the available information. ... We are developing a Bayesian framework to combine all the information we have about the current and future meterological conditions (which are naturally accommodated as priors in a Bayesian scheme) with detailed physical models of the atmosphere. ...

... PPTA timeline . ... List of projects . ... RedGW . ... One of the main goals of pulsar timing array projects is to limit the existence of a background of gravitational waves (GWs). Jenet et al. (2006) developed a method to determine such a limit if (and only if) the pulsar timing residuals were statistically white. In the paper we used data from six pulsars from the PPTA project to obtain a limit. The remaining pulsars were rejected because their timing residuals were not white. ...

... 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 Tube