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Spectral evolution of V838 Monocerotis in the optical and near-infrared in early 2002
We report optical and near-infrared spectroscopy, and opticalspectropolarimetry, of the peculiar variable V838 Mon during themultiple outburst phase in early 2002. The spectral evolution isexceptional. Our earliest spectra (2002 January) are noteworthy fortheir strong absorption lines of barium and strontium in the optical,and bands of CO and circumstellar H2O in the near-infrared.All but the CO weaken or are absent in later spectra. The behaviour ofthe CO band during this phase is extraordinary: initially in absorption,it was observed two months later in optically thick emission. Theexcitation of the CO is probably the result of the propagation of ashock wave at the third maximum. The two spectropolarimetric epochs weretaken 6 and 27 d after the second outburst on 2002 February 8. Thepolarization at both times was measured to be pV~ 2.7 percent. Nearly all of the measured polarization is believed to be due tointerstellar dust, a conclusion that is consistent with previousstudies. At both epochs, however, a weak and variable intrinsiccomponent is thought to be present. Between January and March of 2002the luminosity of V838 Mon increased by a factor of 15 and the apparentdiameter increased fourfold.
| Radial velocities. Measurements of 2800 B2-F5 stars for HIPPARCOS
Radial velocities have been determined for a sample of 2930 B2-F5 stars,95% observed by the Hipparcos satellite in the north hemisphere and 80%without reliable radial velocity up to now. Observations were obtainedat the Observatoire de Haute Provence with a dispersion of 80Ä,mm(-1) with the aim of studying stellar and galactic dynamics.Radial velocities have been measured by correlation with templates ofthe same spectral class. The mean obtained precision is 3.0 km s(-1)with three observations. A new MK spectral classification is estimatedfor all stars. Based on observations made at the Haute ProvenceObservatory, France and on data from The Hipparcos Catalogue, ESA.Tables 4, 5 and 6 are only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr or viahttp://cdsweb.u-strasbg.fr/Abstract.htm
| The Kreinin-Murri Method for Absolute Determination of Equatorial-Star Declinations.
Not Available
| UBV photoelectric photometry in four southern Milky Way fields
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970AJ.....75..324W&db_key=AST
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Pozíciós és asztrometriai adatok
| Csillagkép: | Egyszarvú |
| Rektaszcenzió: | 07h01m14.95s |
| Deklináció: | +00°00'37.9" |
| Vizuális fényesség: | 7.562 |
| Távolság: | 73.099 parszek |
| RA sajátmozgás: | -60.9 |
| Dec sajátmozgás: | 10.4 |
| B-T magnitude: | 8.077 |
| V-T magnitude: | 7.605 |
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