... The concerns here are similar to those for observing bright targets; saturation and blooming of the bright companion PSF must not impact the faint target. Also, one may need to consider subtracting the PSF of the bright object, and effects which limit the accuracy of that subtraction. If the bright companion will saturate and bloom, it will be necessary to rotate the CCD so that blooming along the CCD columns does not obliterate the faint target. ...

... According to the most popular cosmological paradigm, the greater part of the galaxy mass is accumulated in the dark matter halo. ... The polar ring galaxies (PRGs) reveal external rings or disks of gas, dust and stars rotating in a plane roughly perpendicular to the disk of the central galaxy. ... The shape of the dark halo in the model was chosen so as to achieve the best fit to the observed rotation of both galaxies themselves and their polar rings. ... The SPRC-7 galaxy. ...

True Color Image Gallery: Galactic SNR | Magellanic Cloud SNR . ... Distance: 50kpc(distance to LMC, Westerlund(1990) ) . ... Radio Images Page . ... Exposure uf . ... Exposure uf Exposure time of unfiltered event file . Exposure f Exposure time of filtered event file . ... Event 2 FITS File . ... AUX file . ... N H = 0.5(10 22 cm -2 ) Assumed distance: 50kpc (distance to LMC, Westerlund(1990) ) . see fit detail page for more about the fit. see chandra spectrum page for region used. ...

... 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. ... There are additional Service Mode Policies and Service Mode Guidelines regarding the observing conditions. ... Seeing (Phase 1) and Image quality (Phase2) constraints . ... Moon . ...

CHIANTI - an atomic database for emission lines. ... K.P.Dere, E.Landi, H.E.Mason, B.C.Monsignori-Fossi, P.R.Young, 1997, A , 125, 149 . Article: Available from ADS . The Arcetri Spectral Code for thin plasmas . E.Landi M.Landini 1998, A , 133, 1 . ... E.Landi, M.Landini K.P.Dere, P.R.Young, H.E.Mason, 1999, A , 135, 339 . ... K.P.Dere, E.Landi, P.R.Young, G.Del Zanna, 2001, ApJS, 134, 331 . ... G.Del Zanna, B.J.I.Bromage, E.Landi, M.Landini, 2001, A , 379, 708 . ...

... Usually, H I is seen as bright emission against a darker background, but under the right viewing conditions, it can also be seen as dark absorption against a brighter background. In the case where the background is itself H I emission, the hydrogen is said to be self-absorbed, and the radiative transfer process is termed H I self-absorption (HISA). ... Shown below is a single CGPS H I 21cm spectral line channel at a radial velocity of -41 km/s in the Local Standard of Rest, at l =140њ, b =+1њ. ...

... Neutral hydrogen is the best tracer of accreting and outflowing gas, however very hard to detect due to its low column density. ... Simulations predict that in order to detect HI in the extended environment of galaxies, brightness sensitivities well below NHI ~1018 cm-2 are required (e.g. Popping et al. ... Direct aims of the projects include: - Achieve a 1 sigma NHI of 2.5x1017 cm-2 over 20 km/s. - Measure the extended gas content of galaxies to detect gas accretion and outflows. ...

Peremennye Zvezdy", . ... GSC 4232-02515, NSVS 3147658, NSVS 3174760 . ... 14.2-14.9 (R, NSVS); . ... During observations of a secondary eclipse of GSC 04232-02830 (Goranskij et al., 2005) on August 8, 2007, we identified GSC 4232-02515 as a W UMa eclipsing binary. ... VAST software was used for aperture photometry. ... This method produces a light curve with an arbitrary zero point. ... Light Curve . Light curve of GSC 4232-02515 in NSVS magnitude scale. ... gsc423202515_kadar_nsvs.dat . ...

... Many large telescopes will be available on Earth with which to observe the phenomena associated with the Shoemaker-Levy 9 impacts on Jupiter in visible, infrared, and radio wavelengths. ... The impact site of the fragments of Comet Shoemaker-Levy 9 on Jupiter. ... Better knowledge of the effects of Comet Shoemaker-Levy 9 on Jupiter may allow scientists to predict more accurately just how serious could be the results of future impacts of various-sized bodies on Earth. ... 87,500,000,000 . ... 320,000...

... The Westerbork Synthesis Radio Telescope (WSRT) in the Netherlands has been used to survey a section of the galactic plane at a radio frequency of 327MHz. ... Intensity data from the seperate epochs were combined, and the resulting images mosaiced to produce a single image of the entire survey region. ... The WSRT 327 MHz Galactic Plane Discrete Source Catalogue . ... It is available as a unix compressed Postscript file [164 Kbytes] and an ASCII text file [339 Kbytes]. ... Postscript [160 Kbytes] . ...

The Sun is our nearest star and the source of energy for life on Earth. ... For centuries astronomers wondered whether they were clouds floating in the Sun's atmosphere, but we now know that they really are huge regions of magnetic field, about as intense as the field at the poles of an iron magnet. ... Such abrupt events were named solar flares , and what made them especially interesting was that occasionally, after a prominent flare, a magnetic storm would erupt on Earth. ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... Three sixth-form students from St Patrick's Grammar School, Armagh , used the Faulkes Telescope South in Australia in April to observe and measure HW Virginis , an unusual "binary" or double star system suspected to host one or two extrasolar planets orbiting the central stellar pair. ... Armagh Observatory and associated researchers hope to develop this work to look for further evidence of planet-hosting binary star...

... 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. ...

... 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). ...

ARCSAT ID NUMBER: AS01 DESCRIPTIVE TITLE: Search for Short-Period Planets Orbiting Bright White Dwarfs PI: Brett Morris (UW) OBSERVER(S): Brett Morris (UW), Doug Branton (UW) UNCERTIFIED/UNTRAINED OBSERVERS: Undetermined Pre-MAP students ... In addition, since typical white dwarfs are roughly Earth-sized, the transit of an Earth-sized planet can cause changes in brightness on the order of several tens of percent for durations on the order of one minute (Agol 2011). ...

... Exposure Time Calculator (ETC) . Survey processing . ... VISTA is a 4-m class wide field survey telescope for the southern hemisphere, equipped with a near infrared camera (1.65 degree diameter field of view at VISTA's nominal pixel size) containing 67 million pixels of mean size 0.34 arcsec and available broad band filters at Z,Y,J,H,K s and a narrow band filter at 1.18 micron. A wide field visible camera, if constructed, could also be used on VISTA. ... Tile . ... ESO VISTA Public Surveys . ...

... 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 | ...

... In order to compare the number of different evolutionary stages obtained and X-ray luminosity of the chosen X-ray sources with the observed galactic values we use the sum of C/O+O/C , where C and O are the calculated and observed values of a given binary type, respectively. If we make comparison for a number of different binary species (for example, we compare the number of CV, number of X-ray pulsars,   total X-ray luminosity of LMXB, etc.), we write this criterion in the form: . ...

Check out the new images (Jan 18-25) and (Jan 26-Feb 05) of the comet by Rob McNaught. ... Every few years a comet becomes bright enough to be easily seen with the naked eye but only every decade or so are these comparable with comets like Halley. ... Before Jan 13, the comet is not visible in the Australian sky after sunset. ... SOHO images . ... On Jan 12 at approximately 09:00 UT (8pm NSW time), comet C/2006 P1 McNaught appears at the 11 o'clock position in the images. ... STEREO images . ...

The Andromeda Galaxy (M31) . Hot stars burn brightly in this image from NASA's Galaxy Evolution Explorer, showing the ultraviolet side of a familiar face. At approximately 2.5 million light-years away, the Andromeda Galaxy (M31) is our Milky Way's largest galactic neighbor. ... The bands of blue-white making up the galaxy's striking rings are neighborhoods that harbor hot, young, massive stars. ... When observed in visible light, Andromeda s rings look more like spiral arms. ...