Target Acquisition Reference Information . ... In almost all cases where an onboard acquisition will not work (because the object is in a crowded field, or is variable, or is a moving target), it is sufficient to use an early acquisition to get a WFPC2 or FOC image a few weeks in advance of the GHRS observation. ... Explicit BRIGHT and FAINT limits may be specified if you desire, although there is an increased risk of a failed acquisition unless you are confident of those fluxes. ... MAPs . ...

... true false . A boolean switch determining whether the list of to be considered HK parameters shall be explicitly specified with parameter parameters . ... blank separated list of HK parameter names . ... If set to true overrideparameters must contain a list of HK parameter names and overrideparametervalues a corresponding list of validity ranges for those parameters (see below). overrideparameters . ... If withoverrideparameters is set to true the list must contain valid HK parameter names. ...

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. ...

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. ...

Next: Mass change Up: Evolutionary Scenarios of Binary Previous: Stellar Winds From Normal . As mentioned earlier, the duration of the binary evolutionary stage (say, I+I) is determined by the faster evolving component , where is the time each component spends at the corresponding evolutionary stage. ... Next, we should calculate the mass change for the slower evolving companion, the orbital semi-major axis and the eccentricity. Mass change . Semi-major axis change . ...

An early version of the database was used by Garcia ( Garcia et al. 1993 ; Garcia 1993 ) for a general study of group membership of all galaxies with a radial velocity less or equal to 5500 and an apparent magnitude brighter than bt=14. ... From the whole sample 485 groups were build. They are identified by the acronym LGG (for Lyons Galaxy Group). For a galaxy, the LGG number lgg gives the group to which the galaxy belongs. The lgg number is available for 2702 galaxies. ...

Next: Setup Files Up: Frequency Catalog Previous: Frequency Catalog Contents . The parameters of the frequency file tell SCHED over what frequency range the group if usable and on which stations. Most of the parameters are the same as parameters in the setup file since they are meant for direct substitution once the correct frequency group has been identified. ... This will be matched against the station name in the setup file. The name VLBA will be a default for all VLBA stations. ...

... Star formation requires interstellar clouds that are cold and dense enough for self-gravity to overcome internal pressure from gas thermal motions and other factors, thus leading to cloud contraction and eventual collapse to stellar densities. ... Absorption has all of these parameters plus one more describing the fraction of the emission (p) that is behind the absorbing cloud. ... Obser ving Interstellar Hydrogen Clouds Clouds in the ISM can produce either emission or absorption spectra. ...

... Field size . Object name . ... Map size . ... Field size: the approximate size of the map in the Y direction. ... Galaxies: . ... Galaxies, which size exceeds some value depending on the field and map sizes, are displayed with their real positional angles and sizes by 25m isophote. ... In the "tools" fields there are links to the several famous AVO (Astrophysical Virtual Observatory) resources: NED and Simbad databases and DSS2 (Palomar Digitized Sky Survey) images of the corresponding sky area. ...

... A new IRAF task has been developed that automatically identifies linear (line-like) features in an image or set of images. ... In order to automatically detect linear features, the first step is to select pixels in the image (Fig. 1 , left panel) that fall within a given data value range. ... Another aspect of extended linear features is that the image space pixels that describe them are in some way adjacent to one another and have a minimum and maximum length. ...

... We cannot use for this purpose equivalent widths and profiles of HI lines (well known criteria of atmospheric conditions for normal supergiants), since these lines are strongly distorted in the spectrum of IRAS04296 as seen in Fig. ... Figure: Upper: iron abundance FeI (circles) and FeII (crosses) calculated for IRAS04296+3429 with model parameters , and using lines with different excitation potentials EP of a low level; bottom: the same as a function of the equivalent width W . ...

... Bad Astronomy . ... Mad Science . ... Universe Today . ... Keep Bad Astronomy close to your heart, and help make me filthy rich. ... type 1a supernovae seem most useful . ... This is a bright, massive star that explodes after fusing all the light elements in its core. ... That means we can calculate how far away it is. ... This is exactly what we are trying to do with these supernovae; look far enough away that any deviations from flatness of the Universe can be seen. ... Phil Plait . ...

... Luminosity (L) · · · · A source's luminosity is the power that it emits in radiation. ... NB Astronomers often say `flux' when they mean `flux density' · SI units are Wm-2Hz -1 -26 filter · Also used are Jy 10 Wm-2Hz -1 E= РРРF d dA dt Specific Intensity, Surface Brightness (I) · Specific intensity (or surface brightness) is the power received (or emitted) per unit area per unit frequency per unit solid angle. ч F at surface of a spherical source = I · · Specific intensity is independent of distance...

The night sky brightness, together with number of clear nights, seeing, transparency, photometric stability and humidity, are some of the most important parameters that qualify a site for front-line ground--based astronomy. ... Night sky at ESO-Paranal (Chile). ... Night sky brightness data . ... UBVRI night sky brightness at ESO-Paranal during sunspot maximum (A 2003, PDF) . ... The Dancing Sky: six years of night sky observations at Cerro Paranal (Starlight 2007 conference proceedings, PDF) . ...

... Heracles Triplane and Aerospace Systems . The key characteristics of two-stage aerospace systems are determined according to speed and carrying capacity of the aircraft-carrier used . ... So the SPIRAL system hypersonic carrier was expected to launch the second stage by weight 63 tons at a speed corresponding to 6M; whereas launching weight of the MAKS system orbital stage with the use of the An-225 MRIYA heavy subsonic aircraft reaches 275 tons, and the HERACLES aircraft - 450 tons. ...

... Guider functions . ... Guide Sensor Performance . ... Guide Sensor Sky Coverage/ Star Availability . Guide Star Selection Criteria . ... Guide fiber organization and reach at plug plate . ... Plug plate holes for guide stars are identical to those for science FO . ... FOV for each of 9 guide stars is 7.4 arcsec dia. (0.45 mm FO, Sumitomo IGN-05/10) . ... Selected guide stars must have no neighbor stars within TBD (5 arcsec) radius that have a brightness within TBD (5 mag.) of guide stars . ...

Physical and dynamical parameters of particles in outbursting Comet 17 P/Holmes . ... The time depending offset between the center of brightness and center of mass of the comet nucleus has been determined on the ground of positional observations of the comet. ... The motion of these particles allowed subsequent offset between the center of brightness and center of mass of the comet nucleus to be obtained from positional observations. ... comet, dynamical model, outburst, brightness. ...

OPTICAL IDENTIFICATIONS OF INTEGRAL / RXTE SOURCES WITH 1.5-METER OPTICAL TELESCOPE RTT150 I.Bikmaev (1,2), M.Revnivtsev (3,4) , R.Burenin (3) R.Sunyaev (3,4) , N.Sakhibullin (1,2) (1) Kazan State University, Kremlevskaya Str., ... 1, D-85741, Garching bei MЭnchen , Germany (3 (4) ABSTRACT We present the first results of our project on optical identifications of INTEGRAL / RXTE hard X-ray sources by using scientific instrumentations of the 1.5meter joint Russian-Turkish optical telescope RTT150. ...

Magnetic Flux of EUV Arcades and Dimmings as a Relevant Parameter . ... We study events of the 23th cycle, in which major non-recurrent geomagnetic storms (GMS) with Dst < - 100 nT are sufficiently reliably identified with their solar sources in the central part of the disk. ... Figure 3: FD magnitude vs. eruptive magnetic flux . Figure 4: Geomagnetic storm intensiry (Dst index) vs. eruptive magnetic flux . Figure 5: Geomagnetic storm onset and peak transit times vs. eruptive magnetic flux . ...

... Basic Observables: Zero-differenced phase and code ionosphere-free combinations of global GNSS network stations, corrected by P1-C1 satellite code biases (cc2noncc), daily observations with 30 seconds sampling rate Sites coordinates : IGb08 reference frame coordinates and velocities Displacements: solid tides, ocean loading, pole tide loading (IERS 2010) Geometric model : Receivers antennas eccentricities, absolute receiver and ...