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Stars with the Largest Hipparcos Photometric Amplitudes
A list of the 2027 stars that have the largest photometric amplitudes inHipparcos Photometry shows that most variable stars are all Miras. Thepercentage of variable types change as a function of amplitude. Thiscompilation should also be of value to photometrists looking forrelatively unstudied, but large amplitude stars.
| 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
| Ultraviolet Extinction by Interstellar Dust in External Galaxies: M31
Hubble Space Telescope (HST) Faint Object Spectrograph (FOS) spectra ofstars in OB associations of M31 are used to derive the UV extinction byinterstellar dust in M31 by three different methods: (1) comparingspectra of M31 star pairs, (2) comparing spectra of M31 stars to thoseof Galactic standard stars, and (3) comparing M31 star spectra toatmOsphere models. The derived intrinsic M31 extinction curve has anoverall wavelength dependence very similar to that of the averageGalactic extinction curve but possibly has a weaker 2175 A bump,however, with a significance of only 1 σ. This result is differentfrom the LMC (30 Dor)-like curves published earlier, which containedboth intrinsic M31 extinction and "foreground" extinction, and werebased either on low- signal IUE spectra, or on FOS data affected byinaccuracy in the preliminary flux calibration, and were not computedwith the pair method used in this work. In this work, the foregroundextinction component from the Galactic halo is also investigated. Theforeground curve is consistent with the standard curve. While there is aslight indication for a steeper foreground curve than the standard one,the difference is not significant considering the data uncertainties.
| Spectral classification of ultraviolet objects.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1978A&A....66L...9B&db_key=AST
| Luminous stars in a region south of h and chi Persei. With 3 Figures in the Text
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Besorolás csoportokba:
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Pozíciós és asztrometriai adatok
| Csillagkép: | Androméda |
| Rektaszcenzió: | 01h03m41.34s |
| Deklináció: | +44°03'59.0" |
| Vizuális fényesség: | 8.61 |
| Távolság: | 5000 parszek |
| RA sajátmozgás: | -2.4 |
| Dec sajátmozgás: | -4.8 |
| B-T magnitude: | 8.456 |
| V-T magnitude: | 8.598 |
Katalógusok és elnevezések:
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