... The nominal output of a CCD--element to a quantum of light can be given as . ... In the following we ignore the pre-flash and skim term, and hence only take the bias and dark frames into account. The objective in reducing CCD frames is to determine the relative intensity of a science data frame. ... flat frames to determine the term . ... This is achieved by averaging Dark, Flat and Science frames. is further reduced if S=F , then Equation ( ) simplifies to . ...

New reduction of minor planets photographic plates obtained with Pulkovo Normal Astrograph A.A. Berezhnoy Pulkovo Observatory of RAS, Saint-Petersburg, Russia Minor Planet observations at Pulkovo Periodical observations of 14 bright asteroids named Selected Minor Planets (SMP) were performed at Pulkovo since 1948 within the international framework started by works of B.V. Numerov and D. Brouwer. ... 108 133 113 74 124 67 97 88 14 84 64 5 20 19 Epochs (YYYY.MM) 1200 Mean values of total obs. ...

... ATNF Home . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Australia Telescope User Committee . ... Astrophysics graduate student programs . ... Australian Square Kilometre Array Pathfinder . Murchison Radio-astronomy Observatory . ... Parkes radio telescope . Australia Telescope Compact Array . Mopra radio telescope . ... ATCA . ... Visiting Parkes radio telescope . Visiting Australia Telescope Compact Array . ... Parkes radio telescope webcam . ...

... Near Infrared Camera and Multi-Object Spectrometer Instrument Handbook for Cycle 17 > Appendix C: Bright Object Mode > C.1 Bright Object Mode . ... The time taken to read through a quadrant on the array sets a fundamental limit on the fastest electron collection rate which can be achieved by resetting all the pixels. ... In BRIGHTOBJ mode, an ACCUM sequence of operations is performed on one pixel in each quadrant at a time. ... The time required to take a BRIGHTOBJ mode exposure can be rather long. ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... Lightcurve of HW Vir from images obtained using the Faulkes Telescope South, operated by Las Cumbres Observatory . The blue triangles show the difference between two stars whose brightness is constant. ... This shows the value of the Faulkes Telescopes in the follow-up observations of eclipsing binaries with the aim to detect and characterise additional circumbinary companions. ...

... Binary orbits in the acceleration/period plane . Circular Orbits . ... We first present the equations for the period and acceleration of a pulsar in an eccentric binary system as a function of its position in the orbit. ... In Freire, Kramer & Lyne (2001) (from where most of this text and following equations are taken), we describe in more detail how circular binary orbits can be determined from the observed periods and accelerations of the pulsar. ... where is the orbital period of the binary. ...

... 2.3 Establishing the Extragalactic Distance Scale . ... 2.3.2 The Second Rung: Distances to stellar clusters . ... 2.3.4 Distances to Local Group Galaxies . ... The Luminosity Function of Planetary Nebulae . ... 3.2.2 Clusters of Galaxies . ... 4.2 Evidence for Dark Matter as a Function of Scale Size . ... 4.3 Other Dark Matter Indicators for Galaxies . ... What is the nature of the large-scale distribution of matter in the universe as traced by the three-dimensional galaxy distribution? ...

This is a copy of a Press Release from E.S.O. The most recent ESO observations of bright Comet Hyakutake have shown rapid changes in the innermost coma, within a few hundred kilometres from the cometary nucleus. This result has only become possible because of the unusual combination of a bright comet being near the Earth, together with the excellent imaging quality of the ESO 3.5-metre New Technology Telescope (NTT). ... Go to the ESO Homepage for Comet Hyakutake . ESO/La Silla | ...

... Previous: Generalized Linear Multi-Frequency Imaging in VLBI . ... At Astronomical Observatory of Valencia University (OAUV), CCD observations of asteroids and big planets satellites are obtained since 2001 with a big format camera and several telescopes. ... Software for comparison of single and overlapped CCD fields obtained at different epochs has been developed. ... After images measurement in CCD field, catalogue stars are identified and adjusted with images. ...

THE PHOTOMETRIC RESEARCHS OF THE MERCURY'S SURFACE BY MEANS OF DIGITAL MODELS. ... The surface brightness of Mercury was measured Danjon (1933, 1949, 1953) and Harris (1961) in phase angle 3o-123o. The analysis of the various data of the integral photometric gives the results of determination of the main photometric constants for Mercury. ... THE PHOTOMETRIC RESEARCHS OF THE MERCURY'S SURFACE: S.G. Pugacheva The surface brightness of the Mercurian images was established on the geologic map Mercury. ...

Peremennye Zvezdy ( Variable Stars ) 33 , No. ... The new variable star HD 305629, with a Cepheid-like light curve, is demonstrated, from our optical observations and ASAS-3 data, to actually be an ellipsoidal variable star on a highly eccentric orbit. ... During a systematic search of variable stars in the publicly available ASAS-3 database (Pojmanski 2002), apparent variability was found in the star HD 305629 (10 51 34 35, -60 47 57 4, J2000.0; Fig. ... The light curve and color curves of HD 305629. ...

... For more distant stars we must use other techniques. ... Hence if we see a distant galaxy and can pick out any cepheids lying within it, we can calculate its distance. ... Here then is another method to gauge the size of the Universe and there are yet more. volume at high enough temperature a nuclear fusion reaction sweeps across the white dwarf's surface and eventually we will see a spectacularly bright new star (hence nova) in our skies. ... Why is this relevant to the size of the Universe? ...

... Several knots of radio emission in the jets were identified and their motion could be followed between the images. ... The brightness evolution of the knots was found to be consistent with exponential decay of time constant 16 days. ... Knot Velocity and Distance Measurement . ... This paper presents preliminary results of recent 5 GHz observations of SS433 using MERLIN , including a measurement of its distance and an attempt to determine the behaviour of the knot brightness decay. ...

Once students get the hang of it, they can find and measure the brightness of Delta Cephei in a few minutes. ... of Delta Cephei . ... Oct. ... The following table lists the measurements of Delta Cephei made by one amateur astronomer in autumn 1990. ... 4.0 . ... This activity is a simplified version of one that appeared in Hands-On Astrophysics, a series of activities prepared by the American Association of Variable Star Observers with support from the National Science Foundation. << previous page | ...

... Simple X-ray Aperture Photometry Problem : Determine source intensity s and errors for an unresolved (point) x-ray source Know: · Number of counts , C, in source aperture (solid green ellipse) · Number of counts , B, in background aperture (dashed green elliptical annulus) · Areas As and Ab of source and background apertures · f = psf(x,y)dx dy over source aperture · g = psf(x,y)dx dy over background ... What happens if the single observation pdf 's are distinct? ...

... 8, ``Celestial Mechanics'', 2002 Using positional observations of minor planets for improving the orientation of star catalogue Yu. ... But expe­ rience shows that this kind of observations can be used succesfully for improving orientation parameters of star catalogues with respect to dynamical reference system. ... Observations of 90 selected minor planets were used in general solution for their orbital elements, orientation parameters and some parameters of phase re­ duction. ...

IBIS Data Analysis . ... IBIS . ... Flat Fielding - Introduction . The images obtained by IBIS will have intensity variations across the field of view that are not due to the solar image, but rather caused by instrumental effects that alter the observed intensity in each point of the field of view. ... IBIS Flat Fielding Techniques . ... Therefore, it is desirable to obtain the flat field measurements center on a point along the equator near the heliographic center of the solar disk. ...

Experiment COLD . ... JSEC Astronomy . ... The entire project was called "Experiment Cold". ... The best radiometer (in terms of fluctuation sensitivity) known to us, based on a parametric amplifier with a closed-cycle helium cooling system, was used in the experiment; measures were taken to "cool" the radio telescope itself; and a method of controlling the numerous sources of interference was carefully thought out. ...

Next: NICMOS/HST H-band (F160W) Images Up: NICMOS Science Previous: HST NICMOS Observations of . ... Observations of P . ... The NICMOS team has devised a comprehensive program of observations of the Galactic Center. ... Data in hand give a first look at variability and a detailed look at the search for the tip of the main sequence will be discussed where NICMOS has demonstrated adequate sensitivity and photometric precision to identify likely O8-B1 stars at the Galactic Center. ...

... 1997: . For the most representative sample of 277 most nearby galaxies, their masses, separations and tidal indexes were determined based on the BTA observations. ... The most detailed light curve of optical star-like source (corresponding to the gamma-burst of May 8, 1997) was obtained from the BTA observations simultaneously in 4 photometric bands. ... An effect of an abrupt rate slowdown is noticeable in the infrared (~8000A) 36 days after the gamma-ray burst. ... Archive . ...