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The Tokyo PMC catalog 90-93: Catalog of positions of 6649 stars observed in 1990 through 1993 with Tokyo photoelectric meridian circle
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| Spectropolarimetry of SN 1987A - Observations up to 1987 July 8
Spectropolarimetric observations of SN 1987A in the LMC are presented.These are the first such observations of a supernova with asignal-to-noise ratio sufficient to show polarization variations acrossthe spectral lines. Observations have been made at several epochs andcover a number of spectral regions; in most cases these include theregion around H-alpha. In general, the polarization through the lines isdouble peaked above a continuum value. The interstellar component isdiscussed in some detail in order to investigate its effect on thepolarization profile. The presence of polarization shows that thesupernova explosion was asymmetric. The axis and degree of asymmetry isdependent on wavelength. The observations are interpreted in terms ofexisting models, but more detailed modelling will be needed to obtainfull agreement with the observed polarization spectrum. It is alsoinvestigated whether the position angle of the polarization may berelated to the position of the companion source observed using speckleinterferometry. The principal symmetry axis of the supernova envelopeappears to be aligned with the angle to the speckle companion. Themodifications made to the existing spectropolarimetry on theAnglo-Australian Telescope in order to obtain the high signal-to-noiseratios required for the observations are also described.
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Osservazione e dati astrometrici
| Costellazione: | Cassiopea |
| Ascensione retta: | 03h17m41.85s |
| Declinazione: | +70°18'46.2" |
| Magnitudine apparente: | 8.815 |
| Distanza: | 275.482 parsec |
| Moto proprio RA: | -1.8 |
| Moto proprio Dec: | 31.1 |
| B-T magnitude: | 10.055 |
| V-T magnitude: | 8.918 |
Cataloghi e designazioni:
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