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מאמרים קשורים
SW Sextantis in an excited, low state
We present low-resolution spectrophotometric optical observations of theeclipsing nova-like cataclysmic variable SW Sex, the prototype of the SWSex stars. We observed the system when it was in an unusual low state.The spectrum is characterized by the presence of strong Heii and Civemission lines as well as the normal single peaked Balmer emissionlines. The radial temperature profile of the disk follows the expectedT~ R-3/4 only in the outer parts and flattens off inside 0.5times the white dwarf Roche lobe radius. The single peaked emissionlines originate in a region above the plane of the disk, at the positionof the hot spot.
| The Tokyo PMC catalog 90-93: Catalog of positions of 6649 stars observed in 1990 through 1993 with Tokyo photoelectric meridian circle
The sixth annual catalog of the Tokyo Photoelectric Meridian Circle(PMC) is presented for 6649 stars which were observed at least two timesin January 1990 through March 1993. The mean positions of the starsobserved are given in the catalog at the corresponding mean epochs ofobservations of individual stars. The coordinates of the catalog arebased on the FK5 system, and referred to the equinox and equator ofJ2000.0. The mean local deviations of the observed positions from theFK5 catalog positions are constructed for the basic FK5 stars to comparewith those of the Tokyo PMC Catalog 89 and preliminary Hipparcos resultsof H30.
| Halo blue horizontal branch stars - Spectroscopy in two fields
Results are presented of spectroscopic observations at 2-A resolution of44 stars in two fields. A total of 39 are identified as blue horizontalbranch (BHB) stars, RR Lyrae, or main-sequence A stars. The candidateswere selected by color from digitized UK Schmidt direct plates and bythe presence of a strong Balmer discontinuity in their objective prismspectra. Velocities and distances are measured for each of the BHBcandidates. At moderate spectral dispersion the distinction betweenmain-sequence A stars and horizontal branch stars cannot be made on thebasis of hydrogen linewidths alone. Four stars at a distance of 30 kpcin one field are found to have a velocity dispersion of less than 12km/s, and a systematic velocity of 70 km/s with respect to the Galacticrest frame. These stars are not bound to each other but may be thestellar remnants of a recently disrupted halo cluster.
| A library of stellar spectra
Spectra for 161 stars having spectral classes O-M and luminosity classesV, III, and I have been incorporated into a library available onmagnetic tape. The spectra extend from 3510 to 7427 A at a resolution ofabout 4.5 A. The typical photometric uncertainty of each resolutionelement in the spectra is on the order of 1 percent while broad-bandvariations are smaller than 3 percent. Potential uses for the libraryinclude population synthesis of galaxies and clusters, tests of stellaratmosphere models, spectral classification, and the generation of colorindices having arbitrary wavelength and bandpass.
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הכנס מאמר חדש
לינקים קשורים
הכנס לינק חדש
משמש של הקבוצה הבאה
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תצפית ומידע אסטרומטרי
| קבוצת-כוכבים: | פרסאוס |
| התרוממות ימנית: | 04h32m40.83s |
| סירוב: | +31°24'18.0" |
| גודל גלוי: | 8.702 |
| מרחק: | 740.741 פארסק |
| תנועה נכונה: | -0.3 |
| תנועה נכונה: | -11.3 |
| B-T magnitude: | 9.104 |
| V-T magnitude: | 8.736 |
קטלוגים וכינוים:
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