... Colours of stars and galaxies hold information on intrinsic and extrinsic parameters, such as stellar temperatures and galaxy populations, selective absorption and colour changes due different dust contents and inclination angles of galaxies, as well as galaxy redshifts and evolution. ... The colour magnitude diagram of 65000 galaxies to which all above-mentioned quantities and others contribute can only be explained by comparison with simulations. ... Colours are also of technical help. ...

... We performed photometry on both the original and deconvolved images of NGC 6352. ... Aperture photometry was performed on all stars identified in the deconvolved master frames with aperture radii of 4 and 5 pixels for the F555W and F785LP images respectively. ... Fig. 2 indicates that the scatter about the mean faint star sequence is much smaller for the aperture photometry of the deconvolved images than for the PSF fits to the original images. ...

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 | ...

... Analysis of in-orbit data closely follow the CSL data analysis. Stars with known astrometric positions are matched with their image centroids. ... The measured position, the expected position and the offset between the measured and expected positions are calculated and written into a file. ... select catalogued positions for different observations/pointings (e.g. positions of objects in photometric sequence) . ... The new distortion map was generated from in-flight observations of the G153 field. ...

Stellar Clusters are very useful laboratories for empirically studying stellar evolution. ... All cluster stars are at the same distance . All cluster stars have the same physical age . ... CM diagram Young Cluster In this case we see the Main Sequence fully represented. The blue dots represent massive stars with short main sequence lifetimes. ... Thus, identifying the most massive star which is still on the main sequence is an effective means of determining the age of a stellar cluster. ...

... July 13, 1996 . M81: A Bulging Spiral Galaxy . ... Explanation: Few stars are still forming in the old giant spiral galaxy M81. The blue regions in this picture - representing ultraviolet light - highlight regions of bright young stars and star formation and appear rare than in M74 and M33 . ... M81 is therefore classified as spiral galaxy type "Sab" on the Hubble Sequence of Galaxies . ... A massive density wave circulates around the center of spiral galaxies. ... About APOD | ...

... It provides long range planning information to the scheduling team; it provides bright object, timing, and orientation information to the observation planning team; and it provides graphical description of the observations and their constraints. ... The GUI graphically displays the constraints that are computed by Spike and stored in the description files and in the database. ... BOAS processes all bright objects that have entered the database since the last time BOAS was run. ...

... The double star 54 Leonis, spiral galaxy NGC 3198, and emission nebula NGC 3199 . ... Globular cluster NGC 2808, elliptical galaxy NGC 2986, and the Sextans Dwarf . ... Generations of stars in a globular . Hubble finds three generations of stars formed early in globular cluster NGC 2808's life, instead of a single "baby boom." ... The analysis of Hubble data from the massive globular cluster NGC 2808 provides evidence that star birth occurred over three generations early in the cluster's life. ...

... 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). ...

Nova in M31 2000 3 . ... From Giovanni Sostero (Remanzacco Observatory): at the end we have found a good Nova candidate in the course of our monitoring program in M31. ... Remanzacco Observatory Light curve This is a preliminary lightcurve of Nova M31-3 from the images we collected and those provided by others. ... vsnet-alert 5346 ] [FWD] Suspected Nova in M 31 . ... vsnet-alert 5349 ] (fwd) M31 possible nova . ... vsnet-alert 5355 ] [FWD] New image of the possible Nova in M31 (GSo) . ...

We present quasi-simultaneous multi-colour optical/near-IR photometry for 157 radio selected quasars, forming an unbiassed sub-sample of the Parkes Flat-Spectrum Sample. ... The spectral energy distributions of the radio- and optically-selected sources are quite different. ... We show that the colours of our red quasars lie close to the stellar locus in the optical: they will be hard to identify in surveys such as the Sloan Digital Sky Survey. ...

... A hundred years later, a handful of Tunguska-sized asteroids have been spotted by telescopes, but most remain unseen. The asteroid designated 2008 TC3 , which made the news on October 6th before colliding with the Earth on October 7th was too small to constitute a part of the "Earth impact hazard". ... 2008 TC3, for example, finally exploded in the atmosphere above Sudan . ... Wednesday, 8 October 2008 01:15 . International Year of Astronomy, Ireland National Node . ...

Direct Electron Imaging Using Back Thinned CCD's . ... where, Vim is the maximum radial emission energy of photoelectrons from the cathode (eV), Vs is the cathode to anode voltage (V), k is the spatial frequency (2 p lp/mm), L is the cathode to anode spacing of the proximity focused diode (mm), d is the field-free region thickness(mm), h is the backscattering coefficient, (G/G 0 .) is the ratio of the average EBS gain of the secondary electrons to the primary gain, and W is the CCD pixel pitch (mm). ...

... IC 405: The Flaming Star Nebula . ... A Superwind from the Cigar Galaxy . ... This composite image was made from 22 separate pictures of the Moon and Sun all taken from Chisamba, Zambia during the total phase of the 2001 June 21 solar eclipse. ... Leonids Over Indian Cove . ... Canis Major Dwarf: A New Closest Galaxy . ... For many years astronomers thought the Large Magellan Cloud (LMC) was closest, but its title was supplanted in 1994 by the Sagittarius dwarf galaxy. Leonids from Leo . ...

Two major reasons: the number of stars isn't really seven (it's many more), and they all have different brightnesses, so that you see more or fewer of them depending on viewing conditions. The brightness of stars is measured on the magnitude scale, where the most prominent stars in the sky are around 1st magnitude, and the faintest you can see with your eye are about 6th. ... I think this makes it quite likely that the list will be truncated at Taygeta, giving six visible stars. ...

... Search . ... Astrophysics Group . Research . ... Research and Instrumentation . ... While this seems an extraordinary endeavour, in light of what we have learnt about Solar System planets, only a handful of key ingredients are required to start characterising an exoplanet. ... The NGTS project is a partnership between the University of Cambridge, Queen?s University Belfast, University of Warwick, University of Leicester, Observatoire de Geneve, DLR (Berlin) and Universidad Catolica de Chile. ...

. The measuring unit of the electrical impedance tomograph. The belt with electrodes for measurements on thorax . The EIT animation reconstructed from the data measured on the volunteer's thorax: . Right . Anterior . The animation represents one respiratory cycle, the cardiac pulsations are visible also. The static visualization is demonstrated: 1 - spinal column, 2 and 3 - right and left lungs, 4 - heart. The brightest colors correspond to highest conductivity .

Microsymposium 38, MS082, 2003 (A4 format) EVALUATING THE STRUCTURE OF THE SURFACE LAYER OF MERCURY. ... Photometric Analysis of the Lunar Surface Analogue. ... The phase function obtained directly on some segments of the lunar surface: 1- phase function of the Moon, 2 - phase function of Mercury, 3 - phase function of segments, converted to the lunar phase function system (correlation 0.8), 4 - phase function of segments, converted to the Mercurian phase function (correlation 0.9). ...

Introduction This catalogue contains mainly the atomic data needed in the astrophysical investigations of low-density plasma. It is a revised and extended version of the "Catalogue of Atomic Data for the Rarefied Astrophysical Plasma" (Golovatyj et al. ... Low-density plasma. ... In the present study we represent only the atomic data for computation of sp ectra of low-density astrophysical plasma (most known kinds of it are gaseous nebulae), their thermal and ionization structure. ...

Definitions of Magnitudes and Surface Brightness 1 The magnitude system 1.1 Apparent magnitude Astronomers are stuck with the antiquated old system of magnitudes and so a clear explanation of what this system is and how it relates to more sensible units is important. ... 1.2 Absolute magnitude Absolute magnitude is a logarithmic luminosity scale. ... One usually goes by the round about process of referring to the absolute magnitude of the sun. ... Magnitudes and surface brightness 6/6 ...