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Magnetic field measurements of CP stars from hydrogen line cores
We present the results of measurements of magnetic fields of chemicallypeculiar (CP) stars, performed from the shifts between the circularlypolarized components of metal and hydrogen lines (the Babcock method).The observations are carried out with an analyzer of circularpolarization at the 6-m telescope of the SAO RAS. We found that for theabsolute majority of the objects studied (in 22 CP stars out of 23), themagnetic fields, determined from the Zeeman shifts in the hydrogen linecores, are significantly lower than those obtained from metal lines inthe same spectra. This disparity varies between the stars. We show thatinstrumental effects can not produce the above features, and discuss thepossible causes of the observed effect. The discovered condition revealsa more complicated structure of magnetic fields of CP stars than asimple dipole, in particular, a reduction of the field strength in theupper atmosphere with the vertical gradient, significantly higher thanthe dipole.This paper is based on data obtained at the Russian 6-m telescope.
| Main-sequence magnetic CP stars III. Results of magnetic field measurements
We present the third part of the survey of magnetic parameters ofmain-sequence magnetic CP stars. We analyze the main definitions andterminology, basic data on the magnetic fields of CP stars (catalogs,the history of the stellar magnetism research, the main observationalresults obtained over 60 years of studies). We describe the modern viewson the properties of magnetic CP stars, i.e. their geometric structure,distribution of field strengths, magnetic field and rotation, magneticfield and energy distribution anomalies, and the evolutionary status ofmagnetic CP stars. We conclude that the observational data mostlysupport the theory of the relict origin and evolution of magnetic fieldsof CP stars.
| Magnetic fields of chemically peculiar stars. II: Magnetic fields and rotation of stars with strong and weak anomalies in the continuum energy distribution
We make a comparative analysis of magnetic fields and rotationparameters of magnetic CP stars with strong and weak anomalies in thespectral energy distribution. Stars with strong depressions in thecontinuum at 5200 Å are shown to have significantly strongerfields (the mean longitudinal component of the fields of these stars is< B e> = 1341 ± 98 G) compared to objects withweaker depressions (< B e> = 645 ± 58 G). Starswith stronger depressions are also found to occur more commonly amongslow rotators. Their rotation periods are, on the average, about 10 dayslong, three times longer than these of stars with weak depressions(about three days). This fact is indicative of a decrease of the degreeof anomality of the magnetic stars continuum spectrum with increasingrotational velocity. Yet another proof has been obtained suggesting thatslow rotation is one of the crucial factors contributing to thedevelopment of the phenomenon of magnetic chemically peculiar stars.Magnetic CP stars with weak depressions at 5200 Å are intermediateobjects between stars with strong depressions and normal A- and B-typestars both in terms of field strength and rotational velocity.
| Catalogue of Ap, HgMn and Am stars
We present a catalogue of 8205 known or suspected Ap, HgMn and Am stars.This paper is a major update of our first edition of the catalog of Apand Am stars and includes revised identifications, additional stars andrevised information obtained from the literature.Catalogue (full Table 1) is only available in electronic form at the CDSvia anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/498/961
| Catalogue of averaged stellar effective magnetic fields - II. Re-discussion of chemically peculiar A and B stars
This paper presents a catalogue and the method of determining averagedquadratic effective magnetic fields for 1212main-sequence and giant stars, and 11 white dwarf stars. The catalogueincludes stars that are members of several open clusters. We havecompiled measurements of the longitudinal magnetic field for thosestars, which were scattered in the existing literature. A new parameter,magnetization (MA), has been defined, and we present values of MA forstars of various spectral classes. Our sample includes a subset of 610chemically peculiar early-type stars. We confirm the conclusion of ourprevious study that the number distribution of all chemically peculiarstars versus the averaged magnetic field strength is described by adecreasing exponential function. Relations of this type also hold forstars of all the analysed subclasses of chemical peculiarity.Magnetization tends to correlate with the effective temperature only athigh MA, for He-weak and He-rich stars.
| Magnetic fields of chemically peculiar stars. I. The catalog of magnetic CP stars
This is the first paper of the series dedicated to the analysis of themagnetism of chemically peculiar (CP) stars of the upper Main Sequence.We use our own measurements and published data to compile a catalog ofmagnetic CP stars containing a total of 326 objects with confidentlydetected magnetic fields and 29 stars which are very likely to possessmagnetic field. We obtained the data on the magnetism of theoverwhelming majority of the stars solely based on the analysis oflongitudinal field component B e . The surface magneticfield, B s , has been measured for 49 objects. Our analysisshows that the number of magnetic CP stars decreases with increasingfield strength in accordance with exponential law, and stars with B e exceeding 5kG occur rarely (about 3% objects of ourlist).
| New magnetic chemically peculiar stars
Spectropolarimetric observations of 96 chemically peculiar (CP)main-sequence stars have been carried out at the 6-m telescope at theSpecial Astrophysical Observatory of the Russian Academy of Sciences(SAO RAS) with the aim of searching for the presence of stellar magneticfields. The stars selected for investigation were CP stars known to havestrong anomalies in the wavelength region of the continuum fluxdepression around λ 5200Å. This selection was conductedwith the aid of low-resolution spectral observations, made with the SAORAS 1-m telescope, and of published differential photometric data.Magnetic fields have been successfully detected in 72 stars of whichonly three stars were previously known to have magnetic fields. For twostars, the longitudinal component of the magnetic field Beexceeds 5 kG: HD178892 - 7.4 kG, and HD258686 - 6.7 kG. We failed toreliably detect the magnetic field in the other 24 CP stars. These starsare mostly fast rotators, a feature which hampers accurate measurementsof Be. It is demonstrated in this paper that selectingcandidate magnetic stars by considering their photometric indices Z orΔa, or alternatively, by inspecting low-resolution spectra aroundthe λ5200Å flux depression, considerably increases thedetection rate.This paper is based on data obtained at the 6-m telescope of the RussianAcademy of Sciences.E-mail: dkudr@sao.ru
| Catalogue of averaged stellar effective magnetic fields. I. Chemically peculiar A and B type stars
This paper presents the catalogue and the method of determination ofaveraged quadratic effective magnetic fields < B_e > for 596 mainsequence and giant stars. The catalogue is based on measurements of thestellar effective (or mean longitudinal) magnetic field strengths B_e,which were compiled from the existing literature.We analysed the properties of 352 chemically peculiar A and B stars inthe catalogue, including Am, ApSi, He-weak, He-rich, HgMn, ApSrCrEu, andall ApSr type stars. We have found that the number distribution of allchemically peculiar (CP) stars vs. averaged magnetic field strength isdescribed by a decreasing exponential function. Relations of this typehold also for stars of all the analysed subclasses of chemicalpeculiarity. The exponential form of the above distribution function canbreak down below about 100 G, the latter value representingapproximately the resolution of our analysis for A type stars.Table A.1 and its references are only available in electronic form atthe CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/407/631 and Tables 3 to 9are only available in electronic form at http://www.edpsciences.org
| New Magnetic Chemically Peculiar Stars
Not Available
| HDE 343872 and BD -03.987 - new magnetic CP stars
With the purpose of searching out magnetic stars, observations of CPstars having a strong depression at a wavelength of about 5200 Åhave been carried out with the SAO RAS 6 m telescope. We have discoveredtwo new magnetic stars, HDE 343872 and BD -03.987, with a high degree ofreliability. The longitudinal component Be of the magneticfield in the star HDE 343872 varies with a period of 8.724 days from-1kG to +4kG; three measurements of Be for the object BD-03.987 yield a value of about +(3-4) kG. Another two CP stars, HD 29925and BD+17.3622 are, apparently, magnetic, but the results needconfirmation.
| The Henry Draper Extension Charts: A catalogue of accurate positions, proper motions, magnitudes and spectral types of 86933 stars
The Henry Draper Extension Charts (HDEC), published in the form offinding charts, provide spectral classification for some 87000 starsmostly between 10th and 11th magnitude. This data, being highlyvaluable, as yet was practically unusable for modern computer-basedastronomy. An earlier pilot project (Roeser et al. 1991) demonstrated apossibility to convert this into a star catalogue, using measurements ofcartesian coordinates of stars on the charts and positions of theAstrographic Catalogue (AC) for subsequent identification. We presenthere a final HDEC catalogue comprising accurate positions, propermotions, magnitudes and spectral classes for 86933 stars of the HenryDraper Extension Charts.
| General catalogue of AP and AM stars
A catalog of all the known Ap and Am stars, containing a total of 6684objects, was prepared. The few stars that were wrongly considered as Apor Am star are noted as well as some others for which their identity asAp or Am stars is not yet well established. The catalog gives theidentificators and the main observational data for each star, includingthe magnitude, color, spectral type, duplicity, periodicity, magneticfield, and projected rotational velocity.
| Walraven photometry of nearby southern OB associations
Homogeneous Walraven (VBLUW) photometry is presented for 5260 stars inthe regions of five nearby southern OB associations: Scorpio Centaurus(Sco OB2), Orion OB1, Canis Major OB1, Monoceros OB1, and Scutum OB2.Derived V and (B - V) in the Johnson system are included.
| UVBY observations of A, F, G and K field stars
Photoelectric data in the uvby system have been obtained for about 800southern stars of the Hipparcos Input Catalog (Grenon, 1982, 1985). Mostof the stars are F and G main sequence and fall in the magnitude range V= 8-11.
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Pozíciós és asztrometriai adatok
| Csillagkép: | Orion |
| Rektaszcenzió: | 05h03m34.58s |
| Deklináció: | -02°58'46.0" |
| Vizuális fényesség: | 9.559 |
| RA sajátmozgás: | 4 |
| Dec sajátmozgás: | -7.4 |
| B-T magnitude: | 9.636 |
| V-T magnitude: | 9.566 |
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