Detection technique . We are using ISIS , the optimal image subtraction method developed by C. Alard & R.H. Lupton, to search for SNe in our images. ... The second image shows the same subtraction, but after the convolution of the best image with ISIS: . ... For this reason, we are suggested to search for nuclear SNe with NICMOS on HST, to exploit its stable PSF, sensitivity and angular resolution to detect from space nuclear obscured SNe which might have been missed by ground-based surveys. ...

... A three-cell test section roughly representative of the primary mirror was provided for this test by the Steward Mirror Lab. ... Additionally, the tests are intended to determine relative airflow vs. pressure drop characteristics for each of the air flow patterns so the results can be evaluated both as a function of flow rate and of pressure drop along the flow path. ... The bottom (top as installed) was cut out so it could close the chamber for heating and be removed for the cooling tests. ...

For solar wind dials without any explanatory text, see this page . ... There are three logs, one for each condition index ( K P , Solar Wind ,and NOAA/SEC .) ... More about the solar wind's recent behavior can be found on my Current Solar Wind Conditions page. ... Other items of interest include NOAA/SEC Current Conditions , my composite current Auroral Images page, Windows on the Universe: Space Weather , and Public Outreach Index, Department of Space Physics and Astronomy, Rice University . ...

Next: The Scenario Machine: Operational Up: Evolution of Magnetic Rotators Previous: Ejector-propeller hysteresis . ... The length of this segment is determined by the eccentricity. ... In this case no hysteresis occurs and transitions E -- P and the reverse take place in symmetrical points of the orbit. ... Here EP means a mixed state of the rotator at which it is in the ejector state during one part of the orbit, and in the propeller state during the rest of the orbital cycle. ...

We model the spectral chanages of late oxygen-rich Miras observed in different pulsation phases. From a combination of variable near-IR spectra and UKIRT spectrophotometry of the 9.7 \mu m silicate dust emission feature in different phases we study the influence of the changing atmospherical circumstances on the conditions in the circumstellar dust shell. ... A comparision with the modelling results for another long period Mira U Ori is also provided. ...

... Research objects and scientific purposes . Space scientific program includes development and launch of two supersmall spacecrafts "Universitetskiy" and "Kompas-2" intended for monitoring of radiation conditions near the Earth. ... All the studies conducted in the near-Earth space are characterised by strong radiation fields. ... The circular polar orbits, which cover all the near-Earth space, are the most favorable for comprehensive studies of the radiation conditions near the Earth. ...

... I tried reducing the field with five different model point-spread functions (PSFs): (1) a spatially invariant PSF derived from ten bright stars in the test image itself; (2) a quadratically varying PSF derived from the NGC 1850 frames discussed by Stetson (1994b); and (3) spatially invariant, (4) quadratically varying, and (5) cubically varying PSFs derived from grids of model profiles generated with Tiny TIM by Shaun M. Hughes. ...

... This calibration approach is recommended when dealing with high frequency data from the old ATCA correlator, especially at 3mm wavelengths. ... The approach described here exploits the dual frequency bands that were available with the old correlator. ... Rather the current approach assumes that you have a single Miriad dataset containing bandpass calibrator, phase calibrator, flux density calibrator and program source. ... MFCAL . ... Input multi-source, dual-band dataset. select=source(1921-293) . ...

... Assured of a reliable method of solving the normal equations, we now consider the equations of condition. The observed magnitude m of a star at M air masses with true instrumental magnitude is modelled as ([ 10 ], [ 28 ]) . ... The effective extinction coefficient depends on the effective spectral gradient [ 29 ] of the star, for which we use some color index, affected by half the atmospheric reddening ([ 26 ], [ 10 ]): . ... Thus, for the B band of UBV, we use the (U-V) color. ...

Atmospheric influence on the different radio-engineering system functioning . ESTIMATION OF ATMOSPHERIC OPTICAL CHARACTERISTICS AND REMOTELY SANSED IMAGE CORRECTION . ... Direct transmittance estimation results for 12 channels of the spectrometer CHRIS. ... We have managed to develop a direct method of estimating the discrete Normalized Atmospheric Point Spread Function (NAPSF) from available images alone, not using any external sources of information about the atmosphere. ... IRE RAS 1996-20 11 ...

... Laboratory . ... webmaster@izmiran.ru . ... Institute of Terrestrial Magnetism, Ionosphere, and Radiowave Propagation, Russian Academy of Sciences, Troitsk, Moscow region, 142190 Russia . e-mail: karp@izmiran.ru . ... It is also shown that the problem of the MIT shape variations with increasing magnetic activity cannot be solved merely by a data averaging. ... The MIT shape depends on many factors including altitude, longitude, local time, season, and solar and geomagnetic activity. ...

... In the pn-CCD, 768 individual amplifiers allow fast readout, but imply different gains for the different readout channels which all have to be determined and corrected for. The gains of the 768 readout nodes were derived by comparing the position of CTI corrected calibration lines (in adu) with their known energy. ... More details on the CTI and gain correction can be found in []. ...

Crater Gassendi . ... I made this drawing was made on the 26th of november 2001. If you compare this one with the previous drawing of Gassendi (below) the differences are clear. ... This drawing was made on the 28th of september 2001. After nearly a full month without observations I had a one hour gap between the thicker clouds. ... This drawing was made on the 29th of august 2001. ... This drawing was made on the 27th of august 2001. ... This drawing was made on the 25th of august 2001. ...

... Science Users Information > Observing with ESO Telescopes > Phase 2 Preparation > Observing conditions . ... Service Mode Philosophy . ... The following definitions of the observing conditions are common between Phase 1 preparation and Phase 2 preparation, as well as between Service Mode and Visitor Mode observations. ... Seeing (Phase 1) and Image quality (Phase2) constraints . ... Please note that observing conditions requested at Phase 2 should match those at Phase 1 (see Service Mode Policies). ...

Observations of stellar magnetic fields is a powerful method to study of different non-stationary effects in our Galaxy and behavior of plasma under astrophysical conditions. ... Investigations of stellar magnetism by means of Zeeman measurements of polarized spectra of different stars are one of the most significant observational programme on the 6-m telescope BTA of our Observatory. ... Laboratory for the Stellar Magnetism Study . ... Laboratory for the Stellar Magnetism Study of SAO of the RAS . ...

Next: Filtering ROSAT HRI data Up: ROSAT HRI Recipes Previous: Correlating Spectral Data with . Although the spatial variation of the quantum efficiency across the HRI is nominally within 10% for most of the detector, occasionally it may be desirable to flat-field a map with preflight calibration measurements. ... Store the new gain map image using ``blink" in SaoImage. ... The quantum efficiency correction (QEC) is the inverse of the intensity determined from the QE map at the source position. ...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2004 March 25 . An Orion of a Different Color . ... But the striking picture combines images taken through three separate filters, each designed to record different emission lines - light from Sulfur, Oxygen, and Hydrogen atoms glowing in the tenuous nebular gas. ... About APOD | ... NASA Web Site Statements, Warnings, and Disclaimers . ...

... An Orion of a Different Color . ... It is a familiar object though, the grand stellar nursery known as the Orion Nebula . But the striking picture combines images taken through three separate filters, each designed to record different emission lines - light from Sulfur, Oxygen, and Hydrogen atoms glowing in the tenuous nebular gas. At such low densities , Sulfur and Hydrogen atoms emit red colors while Oxygen glows green. ... Publications with keywords: Orion Nebula . ... The Heart Of Orion . ...

... What is the notion time? ... Generally speaking, it is an order of changing events, an order of constantly changing conditions of solids, Universe - being. ... The time, determined for the given longitude, is called the local time . ... A uniform system of time counting - ephemeris time is tested by observations of the Moon turning around the Earth. Fully independent from astronomic observation uniform system of the time counting is based on the concept of atomic second (see quantum watches ). ...

... In this activity, students will observe that the faintest stars which they can see in the sky are affected by many things: the adaptation of their eyes to the dark, the presence of clouds or haze, the time of year, and the presence of light pollution. General Information . ... After completing this activity, students should have a better understanding of the practical processes for dealing with the light pollution problem and with other environmental and societal issues. << previous page | ...