... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2001 May 10 . Spirals On Edge . ... When seen edge-on, their appearance is very different but no less striking as their central regions bulge and dark cosmic dust lanes appear silhouetted against starlight from flattened galactic disks. ... About APOD | ...

Next: Imaging Polarimetry with NICMOS Up: NICMOS Data Calibration and Previous: The Photometric Performance of . ... NICMOSlook and Calnic C . ... Extracting spectra from a large number of NICMOS grism images requires a convenient interactive tool which allows a user to manipulate direct/grism image pairs. ... NICMOSlook and Calnic-C are two programs that were designed to take advantage of the fact that the NICMOS grism mode typically consists of taking both a direct and a grism image. ...

... This script also shows a simple but crude way of displaying more feedback while operating: it opens the DIS Expose window. ... As always, get permission to use DIS before commanding it. import TUI.TUIModel def init(sr): """Open the DIS Expose window so the user can see what's going on.""" tuiModel = TUI.TUIModel.getModel() tuiModel.tlSet.makeVisible("None.DIS Expose") def run(sr): """Sample script to take a series of DIS calibration images and demonstrate looping through data in Python. ...

... A detector map is used to provide a grid of positions over which to calculate and flux weight the ARF. The default detector map is 'flat' which has a weighting of 1.0 for each detector map pixel and is rectangular having sides which just encompass the region specified in the DSS. Only detector map pixels falling within the source region are included in the ARF calculation, e.g. for a circular source box, the pixels in the corners of the detector map will be ignored. ... flat : . ...

Scale-heights of the Galactic disk subsytems with different ages and metallicities . V.Marsakov & Yu. ... It is based on the fact, that all stars cross the disk plane several times during their Galactic orbital period. ... We have used our representative sample of nearby disk F2-G2 stars Marsakov & Shevelev (1995) in which fundamental stellar parameters was determined on the basis of published date on uvby-photometry, proper motion and radial velocities. ... Marsakov V.A., Shevelev Yu.G. Bull. ...

Pyramid Ice Crystal Halos Over Finland . ... This actually happens when a nearly transparent sheet of pyramid shaped ice crystals falls from the sky in a common orientation. ... An amazing display of pyramid ice crystal halos was captured on June 5 above Tampere , Finland . Visible above are very usual sun halos of 9, 18, 20, and 23, and 24 degrees. In contrast, thin and flat falling ice crystals will produce a halo of 22 degrees only. ... NASA Web Site Statements, Warnings, and Disclaimers . ...

... Wavelet analysis works most convincingly on complicated data sets. ... These wavelet maps promptly represent an overwhelming amount of information, that must be reduced in order to be useful. The reduction can take two basic different forms, and countless variants. In the sift-and-discard approach, features of interest are enhanced and the rest is removed from the wavelet maps: applications such as denoising or event identification are representative. ... Mon Nov 13 10:51:25 EST 1995 ...

... AstroCC is a coordinate conversion utility for astronomy. It accepts an object designation or the coordinates of an object and calculates coordinates in alternative systems, and at different dates, times, and locations. It also provides lunar and bright planet coordinates to aid in planning observations. ... BJD values may also be retrieved from http://astroutils.astronomy.ohio-state.edu/time/utc2bjd.html which is based on Eastman et al. ... Coordinate data are obtained from SIMBAD. ...

... Description . Catalog . ... In the Catalog, we publish equatorial (ЮБ 2000 , ЮД 2000 ) and galactic (l,b) coordinates of cluster centers derived as the position of overdensity in 2MASS catalog (Koposov et al. ... Distances, color-excesses and ages are the mean-square values calculated using all available evaluations from different color-magnitude diagrams. ... There are individual pages for every cluster where all available plots and parameters are published. ... 2002). ...

Databases (NSDC) of the Natural Planetary Satellites. ... NSDC: Database of astrometric observations of Natural Planetary Satellites . ... They are thoroughly looking for observations in different sources, creating their owndatabases which are then mostly inaccessible to other researchers. ... In the file "content" with explications, the reference is given to the data source as well as the bibliographic reference. ... Data sources. ... Why a specific bibliographic database for Natural satellites? ...

... Next, the screen displays "Press 0 to align or Mode for Menu." Press "0" if you wish to begin Automatic alignment (or Easy Align, depending on your telescope model), or press Mode if you wish to choose a manual alignment method ("Automatic Alignment" displays, and you can press MODE to go through the menu to find other alignments). ... Note: If you press the "?" key while "Ctr Brightest Star" displays, the alignment star that AutoStar has chosen will display. ... Alignment successful" displays. ...

Software Forum Message . Forums: . ... God and Science ћ SETI ћ Software ћ UFO ћ XEphem . ... Discussion Forums | Astronomy Software Discussion | ... Starry Night Pro 5 Display Problems . Forum List | ... Starry night problem - danhed - October 14, 2005 - 10:14 UTC . ... www.astronomy.net . About Astronomy Net | Advertise on Astronomy Net | ... Forum posts are Copyright their authors as specified in the heading above the post. "dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET" . ...

If you were using a Java-enabled browser, you would see a scrolling text sign instead of this paragraph. ... Wiggle your mouse cursor over the applet, you should notice the sign speed up. ... Then, if you go back to the LED page and try it again, Netscape will give you a "NullPointerException" error. ... Everything you see the sign displaying is run entirely by a script. ... The size, size of border, color of border, and even the font that the sign uses are all configurable. ... More on fonts . ...

Stellarium 0.12.3 . ... FileљStructure . ... core . ... 233 љ void azimuthalGridDisplayedChanged( const bool ) const ; . 234 љ void azimuthalGridColorChanged( const Vec3f & newColor) const ; . 235 љ void equatorGridDisplayedChanged( const bool displayed) const ; . 236 љ void equatorGridColorChanged( const Vec3f & newColor) const ; . 237 љ void equatorJ2000GridDisplayedChanged( const bool displayed) const ; . 238 љ void equatorJ2000GridColorChanged( const Vec3f & newColor) const ; . ...

... For given geographical longitude and time zone show the current data and time, Universal data and time, current local star time. ... Accept 10 different data formats (data&time, data with decimal day of month, data with decimal day of year, decimal year, some Julian dates), calculate from any formate to others, show day of week. Current data and time direct insertion function is exists. ... Calculate angular distance between two points at the sky by its equatorial coordinates. ...

... The extinction in terrestrial atmosphere. ... 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. ... Calculate the air mass for given zenith distances in 1st 54.9 11800 column, and write the result into the 2nd column. ... Spectral observations. ... Calculate the radial velocity Vr of the star on each date, the results of measurements and write calculations into the table. ...

. ATMOSPHERIC INFLUENCE ON THE DIFFERENT RADIO-ENGINEERING . SYSTEM FUNCTIONING . The calculations of the atmospheric impact on terrestrial and satellite communication links with frequencies above 10 GHz using the ITU-R data bank. The correction of the Earth cover optical images obtained from the satellite/ . The Earth atmospheric influence on the radiowave propagation parameters in wide frequency range (from SLF to UV). Contact e-mail: . Pozhidayev Victor, Ph.D - vic@cplire.ru . © IRE RAS 1996-20 11

The ESA/ESO Astronomy Exercise Series 2 . The Distance to Messier 100 as Determined by Cepheid Variable Stars . ... The small variations in distance to the individual Cepheid variable stars in the Cloud are negligible compared with the much larger distance to the SMC. ... In this way Cepheid variable stars can be used as one of the 'standard candles' in the Universe that act either as distance indicators themselves or can be used to calibrate (or set the zero point for) other distance indicators. ...

Institute of Applied Astronomy Russian Academy of Sciences Method of Determining the Orbits of the Small Bodies in the Solar System Based on an Exhaustive Search of Orbital Planes Dmitrii Vavilov, Yurii Medvedev Introduction to the problem: Let we have n 3 positional observations of a body: points in time ( = 1, ) , right ascensions , and declinations . ... Determination of the orbit using the Gauss method of determining orbital elements based on two heliocentric positions and points in time. ...

... It is found that the correlation coefficients between these two parameters calculated separately inside and outside the sunspot formation zone ±30 have cyclic variation and occur in anti-phase. This suggests different mechanisms of formation of the corona in the fields of small, medium, and large scales. ... The relationship between the coronal green line brightness (CGLB) and the magnetic field strength (MFS) has been investigated by constructing the corresponding synoptic maps for the 1977-2001. ...