... 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 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. ...

... Search . ATNF Home . About ATNF . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Parkes radio telescope . ... Parkes | ... A Search for Bright Kuiper Belt Objects . ... Since 1992, 60 large Kuiper belt objects have been detected by ground-based telescopes. ... The detection of brighter objects would improve our ability to determine the Kuiper belt objects' surface composition and provide constraints on the population statistics of different formation mechanisms. ...

... Posts tagged ?background? ... Probability density functions are another way of summarizing the consequences of assuming a Gaussian error distribution when the true distribution is Poisson. We can compute the posterior probability of the intensity of a source , when some number of counts are observed in a source region, and the background is estimated using counts observed in a different region. ... In both cases a background of 200 counts collected in an area 40x the source area is used. ...

... A comparison of the computed and experimental relations F max ( H), as well as comparison of drift scans of point sources across different horizontal cross-sections of the BP with the corresponding computed cross-sections were made. ... The drift scans of the point source 3С84 (H=87 o ) at the wavelength 7.6 cm across the horizontal cross-sections of the BP (black lines) and the computed horizontal cross-sections of the BP corresponding to them (red lines). ...

Next: Reducing the observations Up: PEPSYS general photometry Previous: Influencing the plan . ... If the telescope and instrumentation are unfamiliar to you, you may have trouble keeping to the schedule for the first night or two, so try to work with a previous observer on the equipment for a night or two of training before your observing run. If you fall behind, try to keep as many low-altitude observations of extinction stars as you can, and drop some circumzenithal ones if necessary. ...

... We will consider the rms, (K), for observations with a receiver of system temperature, T , frequency resolution, per polarization, and total integration time per observing cycle, . ... For ``in-band'' frequency switching, the line under investigation is always in the observing band. ... Position Switching or ``Out-of-Band'' Frequency Switching: Here the line is only observed for one half of the time, with noise being present all of the time. ...

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 | ...

... 2002 March 7 . Comet Ikeya-Zhang Brightens . ... Explanation: In the last week , Comet Ikeya-Zhang has become bright enough to be just visible to the unaided eye. Based on its present activity, observers are optimistic that Ikeya-Zhang will become substantially brighter. This composite color image from March 3rd, captured with a wide-field telescope, shows this active comet's bright, condensed coma and a delightful array of subtle structures in its developing tail. ... About APOD | ...

... The Galactic low-mass X-ray binary GS 2023+338 was discovered during the burst on May 22, 1989 with the Japanise satellite Ginga (aka Galaxy). The flux reached 17 crabs (this unit of flux measurement is an bright X-ray source, Crab Nebula) at 10-35 keV. ... No other radio telescope worldwide carried out multi-frequency measurements. ... Upon 14 days the radio flux fell below the detection level at the RATAN-600 in relation to the decrease of the X-ray flux. ...

... The scheduling routines assist in creating an observing list (stored in the startable) from scratch or from another list stored on disk, and computing the visibility of the stars in a specific night and array configuration. The date of observation is taken from the variable date , and the array name from the variable systemid . If these are not defined, defaults are used for date (the next night) and for array (NPOI). ... addstar , stars _char Add one or more stars to the startable. ...

The aim of this assignment is to teach you how to carry out a very common programming task: reading in a bunch of data from a text file, doing something with it then writing the results out again. ... The goal of the assignment is to write a computer program which will select this sample for you. You will pick the micro-quasars to observe from a rather large catalogue, which can be found here: The catalogue is an ASCII (text) file - you can inspect it with a normal text editor. ...

... A technique allowing automatic representation by a relatively small number of independent parameters based on the principal component analysis of data sequences is presented. ... In recent years the spectrum of observed astronomical data can be characterized as greatly varied. ... In this instance, the problem of initial description and classification of newly-observed data becomes most urgent, especially if there is a lack of preliminary observational material and theoretical expectations. ...

... Jupiter's moon Io is turning out to be our Solar System's geologic powerhouse. ... In a report released yesterday and soon to be published in Nature, astronomers have imaged an interesting distant patch of sky with the orbiting Hubble Space Telescope. ... Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and most easily visible open clusters on the sky. Sirius: The Brightest Star in the Night . ... Sirius is the brightest star in the night sky. ...

... Meade Instruments Corporation . ... Autostar Computer Controllers . 497 Autostar . ... One of the most important advances in telescope control in the past 25 years, the Meade #497 Autostar Computer Controller turns the ETX into an automatic celestial object locating system. ... The #497 Autostar Computer Controller plugs into the control panel of ETX-90EC, ETX-105EC, and ETX-125EC telescopes and enables automatic location of more than 30,000 celestial objects. ... about meade | ... Meade 4M | ...

. Sitemap . Contact . Search . Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . This video of a bright fireball was captured by the Observatory's automatic meteor detection system at 23:32 GMT on the 17th of June 2013 (00:32 British Summer Time on the 18th of June). The fireball was also reported to our fireballs database by three observors . The video is also available in these alternative formats: . webm . ogv . Flash . Last Revised: 2013 June 19th .

In this gallery are many images of Low Surface Brightness Galaxies which have recently been discovered and analyzed. ... The central surface brightness of this galaxy is 24.28 . Malin 2 This galaxy is another huge disk galaxy with a scale length of 15 kpc and a redshift of 15000 km/a. The high surface brightness knot in one of its spiral arms actually has the same color, luminosity and H-alpha equivalent width as the entire Large Magellanic Cloud . ... Truly it is a Low Surface Brightness Galaxy. ...

... A star was observed at different zenith distances during one night at the Engelgardt's Astronomical Observatory in the program of atmospheric extinction study at blue. ... The determination of the star's brightness was performed with the method of photon counting. ... Variable star. ... The brightness of the variable star was measured occasionally during the other nights, and moments of maximal values of brightness (15.59m) were received on nights 2­5, the 2nd table. ... JD 2452805. ...

MAIN PAGE . ... Nova Cygni August 1975! ... 1975/76: Comet West! ... Dr. Richard West (4th from left) & AAL members visiting SES Betzdorf on occasion of our club's 25th anniversary - October 1996 . Comet West Information . ... It was the brightest comet visible from Earth since Comet West in 1976. ... 1997: Comet Hale-Bopp! ... Thus Comet Hale-Bopp never got closer to Earth than Earth gets to the Sun. ... Comet Hale-Bopp JPL Page . ... 1999: Total solar eclipse over Luxembourg! ...

The Solar spots - are the dark formations on the Sun's disk. ... The greatest observed spot is 100 thousand kilomiters. The spots are the places of the magnetic fields' getting out to the solar atmosphere. ... That's why they look so dark . ... The Solar convection zone is the layer with the thickness of 150 - 200 thousand kilomiters, situated under the photosphere; the substance of this layer being in convectional movement transformes the energy from inside the Sun's to its surface. ...