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Modelling the formation of double white dwarfs
We investigate the formation of the ten double-lined double white dwarfsthat have been observed so far. A detailed stellar evolution code isused to calculate grids of single-star and binary models and we usethese to reconstruct possible evolutionary scenarios. We apply variouscriteria to select the acceptable solutions from these scenarios. Weconfirm the conclusion of Nelemans et al. (2000) that formation viaconservative mass transfer and a common envelope with spiral-in based onenergy balance or via two such spiral-ins cannot explain the formationof all observed systems. We investigate three different prescriptions ofenvelope ejection due to dynamical mass loss with angular-momentumbalance and show that they can explain the observed masses and orbitalperiods well. Next, we demand that the age difference of our model iscomparable to the observed cooling-age difference and show that thisputs a strong constraint on the model solutions. However, the scenarioin which the primary loses its envelope in an isotropic wind and thesecondary transfers its envelope, which is then re-emittedisotropically, can explain the observed age differences as well. One ofthese solutions explains the DB-nature of the oldest white dwarf inPG 1115+116 along the evolutionary scenario proposed by Maxted etal. (2002a), in which the helium core of the primary becomes exposed dueto envelope ejection, evolves into a giant phase and loses itshydrogen-rich outer layers.
| Tertiary companions to close spectroscopic binaries
We have surveyed a sample of 165 solar-type spectroscopic binaries (SB)with periods from 1 to 30 days for higher-order multiplicity. Asubsample of 62 targets were observed with the NACO adaptive opticssystem and 13 new physical tertiary companions were detected. Anadditional 12 new wide companions (5 still tentative) were found usingthe 2MASS all-sky survey. The binaries belong to 161 stellar systems; ofthese 64 are triple, 11 quadruple and 7 quintuple. After correction forincompleteness, the fraction of SBs with additional companions is foundto be 63% ± 5%. We find that this fraction is a strong functionof the SB period P, reaching 96% for P<3d and dropping to34% for P>12^d. Period distributions of SBs with and withouttertiaries are significantly different, but their mass ratiodistributions are identical. The statistical data on the multiplicity ofclose SBs presented in this paper indicates that the periods and massratios of SBs were established very early, but the periods of SB systemswith triples were further shortened by angular momentum exchange withcompanions.
| Mass loss and orbital period decrease in detached chromospherically active binaries
The secular evolution of the orbital angular momentum (OAM), thesystemic mass (M=M1+M2) and the orbital period of114 chromospherically active binaries (CABs) were investigated afterdetermining the kinematical ages of the subsamples which were setaccording to OAM bins. OAMs, systemic masses and orbital periods wereshown to be decreasing by the kinematical ages. The first-orderdecreasing rates of OAM, systemic mass and orbital period have beendetermined as per systemic OAM, per systemic mass and per orbitalperiod, respectively, from the kinematical ages. The ratio of d logJ/dlogM= 2.68, which were derived from the kinematics of the presentsample, implies that there must be a mechanism which amplifies theangular momentum loss (AML) times in comparison to isotropic AML ofhypothetical isotropic wind from the components. It has been shown thatsimple isotropic mass loss from the surface of a component or bothcomponents would increase the orbital period.
| A catalogue of eclipsing variables
A new catalogue of 6330 eclipsing variable stars is presented. Thecatalogue was developed from the General Catalogue of Variable Stars(GCVS) and its textual remarks by including recently publishedinformation about classification of 843 systems and making correspondingcorrections of GCVS data. The catalogue1 represents thelargest list of eclipsing binaries classified from observations.
| Kinematics of chromospherically active binaries and evidence of an orbital period decrease in binary evolution
The kinematics of 237 chromospherically active binaries (CABs) werestudied. The sample is heterogeneous with different orbits andphysically different components from F to M spectral-type main-sequencestars to G and K giants and supergiants. The computed U, V, W spacevelocities indicate that the sample is also heterogeneous in velocityspace. That is, both kinematically younger and older systems exist amongthe non-evolved main sequence and the evolved binaries containing giantsand subgiants. The kinematically young (0.95 Gyr) subsample (N= 95),which is formed according to the kinematical criteria of moving groups,was compared with the rest (N= 142) of the sample (3.86 Gyr) toinvestigate any observational clues of binary evolution. Comparing theorbital period histograms between the younger and older subsamples,evidence was found supporting the finding of Demircan that the CABs losemass (and angular momentum) and evolve towards shorter orbital periods.The evidence of mass loss is noticeable on the histograms of the totalmass (Mh+Mc), which is compared between theyounger (only N= 53 systems available) and older subsamples (only N= 66systems available). The orbital period decrease during binary evolutionis found to be clearly indicated by the kinematical ages of 6.69, 5.19and 3.02 Gyr which were found in the subsamples according to the periodranges of logP<= 0.8, 0.8 < logP<= 1.7 and 1.7 < logP<=3, respectively, among the binaries in the older subsample.
| A study of the Mg II 2796.34 Å emission line in late-type normal and RS CVn stars
We carry out an analysis of the Mg II 2796.34 Å emission line inRS CVn stars and make a comparison with the normal stars studied in aprevious paper (Paper I). The sample of RS CVn stars consists of 34objects with known HIPPARCOS parallaxes and observed at high resolutionwith IUE. We confirm that RS CVn stars tend to possess wider Mg II linesthan normal stars having the same absolute visual magnitude. However, wecould not find any correlation between the logarithmic line width logWdeg and the absolute visual magnitude MV (theWilson-Bappu relationship) for these active stars, contrary to the caseof normal stars addressed in Paper I. On the contrary, we find that astrong correlation exists in the (MV, log LMg II)plane (LMg II is the absolute flux in the line). In thisplane, normal and RS CVn stars are distributed along two nearly parallelstraight lines with RS CVn stars being systematically brighter by ~1dex. Such a diagram provides an interesting tool to discriminate activefrom normal stars. We finally analyse the distribution of RS CVn and ofnormal stars in the (log LMg II, log Wdeg) plane,and find a strong linear correlation for normal stars, which can be usedfor distance determinations.
| 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
| VLA Radio Positions of Stars: 1978-1995
VLA astrometric positions of the radio emission from 52 stars arereported, from observations obtained between 1978 and 1995. Thepositions of these stars have been obtained and reduced in a uniformmanner. Based on our measurements, the offset of the optical (Hipparcos)frame from the radio reference frame is in agreement with the Hipparcosextragalactic link results, within their mean errors. Comparison of theVLA measurements with the Hipparcos optical positions confirms earlierestimates of the accuracy of these positions as 30 mas. Long-termmeasurements of UX Ari have improved its proper motion.
| WW Dra - ein heller BAV-Programmstern mit vielen Problemen.
Not Available
| The Evolution of Cool Algols
We apply a model of dynamo-driven mass loss, magnetic braking, and tidalfriction to the evolution of stars with cool convective envelopes; inparticular, we apply it to binary stars where the combination ofmagnetic braking and tidal friction can cause angular momentum loss fromthe orbit. For the present we consider the simplification that only onecomponent of a binary is subject to these nonconservative effects, butwe emphasize the need in some circumstances to permit such effects inboth components.The model is applied to examples of (1) the Sun, (2) BYDra binaries, (3) Am binaries, (4) RS CVn binaries, (5) Algols, and (6)post-Algols. A number of problems regarding some of these systems appearto find a natural explanation in our model. There are indications fromother systems that some coefficients in our model may vary by a factorof 2 or so from system to system; this may be a result of the chaoticnature of dynamo activity.
| Determination of the Ages of Close Binary Stars on the Main Sequence from Evolutionary Model Stars of Claret and Gimenez
A grid of isochrones, covering a wide range of stellar ages from thezero-age main sequence to 10 billion years, is calculated in the presentwork on the basis of the model stars of Claret and Gimenez withallowance for convective overshoot and mass loss by the components. Theages of 88 eclipsing variables on the main sequence from Andersen'scatalog and 100 chromospherically active stars from Strassmeier'scatalog are calculated with a description of the method of optimuminterpolation. Comparisons with age determinations by other authors aregiven and good agreement is established.
| Optical positions of 55 radio stars from astrolabe observations from the Yunnan Observatory
The observations by the photoelectric astrolabe at Yunnan Observatoryrelative to the Hipparcos Catalogue and the optical positions of 55radio stars were obtained from observations between 1991 and 2000. Theyall resulted from processing the photon counts obtained by means of theastrolabe after the automation of the instrument. There are 46 stars incommon with the Hipparcos Catalogue. Tables \ref{t1} and \ref{t2} arealso available in electronic form at the CDS via anonymous ftpcdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/383/1062.
| Zwei helle Algosterne fur den Sommer.
Not Available
| Das Brunner Punktesystem.
Not Available
| Beobachtungsergebnisse Bundesdeutsche Arbeitsgemeinschaft fur Veraenderliche Sterne e.V.
Not Available
| Spectroscopic and photometric observations of the short-period RS CVn star RT And
Spectroscopic observations in the range 6500-6700 Å and BVRIphotometry of the eclipsing short-period RS CVn-star RT And arepresented. We determined K1=130 km s-1 andK2=175.8 km s-1 by measurement of the doubleprofiles of the lines Hα and FeI 6678, and obtained the mass ratioq=0.74 and masses of the star components M1=1.23Msun and M2=0.91 Msun. It wasestablished that the emission activity of RT And is associated with itssecondary component. The relative contribution of the secondary star isstronger in the FeI 6678 line than in Hα. A strong emissionfeature between the two profiles of FeI 6678 at phase 0.73 was detectedthat is probably due to the appearance of extended emitting structure.The multicolor light curve of RT And is fitted by two cool spots on theprimary star with equal sizes 21o and temperatures 4980 K andlocated at middle latitudes and longitudes symmetrical to the lineconnecting the star centers. Both spectral and photometric data lead tothe conclusion that the secondary star of RT And is oversized for itsmass.
| The comparative accuracy of photographic observations of radio stars observed at the Engelhardt Astronomical Observatory
At the Engelhardt Astronomical Observatory (EAO), we observedphotographic positions of 113 Galactic Radio Sources (GRS) in the systemPPM catalogue (Rizvanov & Dautov 1998). Analysis of their accuracyis made by comparison with the Hipparcos catalogue (Perryman et al.1997) and astrometric catalogue of radio stars in the radio window fromthe article of Walter et al. (1991). Table 2 is only available inelectronic form at the 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/375/670
| Eclipsing Binaries and the Lutz-Kelker Bias
Using examples from the literature, we demonstrate that ignoring theLutz- Kelker bias may degrade agreement between results derived fromeclipsing binaries and those based on trigonometric parallaxes. Inaddition, we show that eclipsing binaries are excellent standardcandles.
| Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics
The Catalogue, available at the Centre de Données Stellaires deStrasbourg, consists of 13 573 records concerning the results obtainedfrom different methods for 7778 stars, reported in the literature. Thefollowing data are listed for each star: identifications, apparentmagnitude, spectral type, apparent diameter in arcsec, absolute radiusin solar units, method of determination, reference, remarks. Commentsand statistics obtained from CADARS are given. The Catalogue isavailable in electronic form at the CDS via anonymous ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcar?J/A+A/367/521
| 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.
| Comparison of Parallaxes from Eclipsing Binaries Method with Hipparcos Parallaxes
The parallaxes determined by Lacy (1979) by means of eclipsing binariesmethod are compared with the Hipparcos parallaxes for 19 systems. Theresidual scatter of the distance moduli inferred from eclipsing binariesmethod - after allowing for known errors as given by Lacy and Hipparcos- is equal to 0.18 mag. It decreases to 0.08 mag when obviously notfitting semi-detached systems and systems with chromospheric activity ofcomponents are removed from the sample.
| The eccentricities of the barium stars
We investigate the eccentricities of barium (Baii) stars formed via astellar wind accretion model. We carry out a series of Monte Carlosimulations using a rapid binary evolution algorithm, which incorporatesfull tidal evolution, mass loss and accretion, and nucleosynthesis anddredge-up on the thermally pulsing asymptotic giant branch. We followthe enhancement of barium in the envelope of the accreting main-sequencecompanion and dilution into its convective envelope once the starascends the giant branch. The observed eccentricities of Baii stars aresignificantly smaller than those of an equivalent set of normal redgiants but are nevertheless non-zero. We show that such a distributionof eccentricities is consistent with a wind accretion model for Baiistar production with weak viscous tidal dissipation in the convectiveenvelopes of giant stars. We successfully model the distribution oforbital periods and the number of observed Baii stars. The actualdistribution of eccentricities is quite sensitive to the strength of thetides, so that we are able to confirm that this strength is close to,but less than, what is expected theoretically and found with alternativeobservational tests. Two systems - one very short-period but eccentric,and one long-period and highly eccentric - still lie outside theenvelope of our models, and so require a more exotic formationmechanism. All our models, even those which were a good fit to theobserved distributions, overproduced the number of high-period bariumstars, a problem that could not be solved by some combination of thethree parameters: tidal strength, tidal enhancement and wind accretionefficiency.
| An IUE Atlas of Pre-Main-Sequence Stars. II. Far-Ultraviolet Accretion Diagnostics in T Tauri Stars
We use our ultraviolet (UV) atlas of pre-main-sequence stars constructedfrom all useful, short-wavelength, low-resolution spectra in theInternational Ultraviolet Explorer (IUE) satellite Final Archive toanalyze the short-wavelength UV properties of 49 T Tauri stars (TTSs).We compare the line and continuum fluxes in these TTSs with each otherand with previously published parameters of these systems, includingrotation rate, infrared excess, and mass accretion rate. Theshort-wavelength continuum in the classical TTSs (CTTSs) appears tooriginate in a ~10,000 K optically thick plasma, while in the naked TTSs(NTTSs-stars without dusty disks) the continuum appears to originate inthe stellar atmosphere. We show that all of the TTSs in our sample liein the regime of ``saturated'' magnetic activity due to their smallRossby numbers. However, while some of the TTSs show emission linesurface fluxes consistent with this saturation level, many CTTSs showsignificantly stronger emission than predicted by saturation. In thesestars, the emission line luminosity in the high ionization lines presentin the spectrum between 1200 and 2000 Å correlates well with themass accretion rate. Therefore, we conclude that the bulk of theshort-wavelength emission seen in CTTSs results from accretion relatedprocesses and not from dynamo-driven magnetic activity. Using CTTSs withknown mass accretion rates, we calibrate the relationship between M andLC IV to derive the mass accretion rate for some CTTSs whichfor various reasons have never had their mass accretion rates measured.Finally, several of the CTTSs show strong emission from molecularhydrogen. While emission from H2 cannot form in gas at atemperature of ~105 K, the strength of the molecular hydrogenemission is nevertheless well correlated with all the other emissionsdisplayed in the IUE short-wavelength bandpass. This suggests that theH2 emission is in fact fluorescent emission pumped by theemission (likely Lyα) from hotter gas.
| Spin and orbital angular momentum exchange in binary star systems. II. Ascending the giant branch: a new path to FK Comae stars
Using the model by Keppens (1997), we investigate the angular momentum(AM) evolution in asymmetric binary star systems from Zero-Age MainSequence times until at least one component has ascended the giantbranch. We concentrate on stars ranging in mass from 0.9 Msun- 1.7 Msun, in almost synchronous, short period systems(P_orb<9 days). We address synchronization and circularization bytidal interaction, allowing for structural evolution and stellar winds.A Weber-Davis prescription is used to quantify the wind influence,thereby accounting for changes in its acceleration mechanism from theinterplay of the evolving thermal-magneto-centrifugal effects. Weidentify a scenario for fast in-spiraling components with d ln P_orb/dt=~ -{cal O}(10-8) which is primarily driven by faststructural evolution as the heaviest component ascends the giant branch.This leads to the formation of contact systems, which ultimatelycoalesce and form FK Comae-like objects on relatively short timescalesdue to the continuing expansion of the primary. The obtained mass lossrates and orbital period variations d ln P_orb/dt are confronted withtheir observed ranges. The predicted mass loss rates agree with thesolar value on the main sequence and with the Reimers relation in thegiant phase. Observations of period evolution in close, active binariessuggest, however, that other influences than those considered here mustplay an important role. Finally, we point out how the mass asymmetry ofthe binary system can be a crucial ingredient in the angular momentumevolution: while the primary dictates the spin-orbital AM exchange inthe system, the slowly evolving lighter component can develop anefficient magneto-centrifugally driven wind and thereby drain the AMfrom the system.
| Fundamental parameters of nearby stars from the comparison with evolutionary calculations: masses, radii and effective temperatures
The Hipparcos mission has made it possible to constrain the positions ofnearby field stars in the colour-magnitude diagram with very highaccuracy. These positions can be compared with the predictions ofstellar evolutionary calculations to provide information on the basicparameters of the stars: masses, radii, effective temperatures, ages,and chemical composition. The degeneracy between mass, age, andmetallicity is not so large as to prevent a reliable estimate of masses,radii and effective temperatures, at least for stars of solarmetallicity. The evolutionary models of Bertelli et al. (1994) predictthose parameters finely, and furthermore, the applied transformationfrom the theoretical (log g- T_eff) to the observational (M_v-B-V) planeis precise enough to derive radii with an uncertainty of ~ 6%, masseswithin 8%, and T_effs within ~ 2% for a certain range of the stellarparameters. This is demonstrated by means of comparison with themeasurements in eclipsing binaries and the InfraRed Flux Method. Theapplication of the interpolation procedure in the theoretical isochronesto the stars within 100 pc from the Sun observed with Hipparcos providesestimates for 17,219 stars. Table~1 is only available in electronic format the CDS via anonymous ftp to: cdsarc.u-strasbg.fr (130.79.128.5) orvia http://cdsweb.u-strasbg.fr/Abstract.html
| On X-Ray Variability in Active Binary Stars
We have compared the X-ray emissions of active binary stars observed atvarious epochs by the Einstein and ROSAT satellites in order toinvestigate the nature of their X-ray variability. The primary aim ofthis work is to determine whether or not active binaries exhibitlong-term variations in X-ray emission, perhaps analogous to theobserved cyclic behavior of solar magnetic activity. We find that, whilethe mean level of emission of the sample remains steady, comparison ofdifferent ROSAT observations of the same stars shows significantvariation on timescales <~2 yr, with an ``effective variability''ΔI/I=0.32+/-0.04, where I and ΔI represent the mean emissionand variation from the mean emission, respectively. A comparison of theROSAT All-Sky Survey and later pointed observations with earlierobservations of the same stars carried out with Einstein yields onlymarginal evidence for a larger variation (ΔI/I=0.38+/-0.04 forEinstein vs. ROSAT All-Sky Survey and 0.46+/-0.05 for Einstein vs. ROSATpointed) at these longer timescales (~10 yr), thus indicating thepossible presence of a long-term component to the variability. Whetheror not this long-term component is due to the presence of cyclicvariability cannot be decided on the basis of existing data. However,assuming that this component is analogous to the observed cyclicvariability of the Sun, we find that the relative magnitude of thecyclic component in the ROSAT passband can, at most, be a factor of 4,i.e., I_cyc/I_min<4. This is to be compared with the correspondingbut significantly higher solar value of ~10-10^2 derived from GOES,Yohkoh, and Solrad data. These results are consistent with thesuggestions of earlier studies that a turbulent or distributive dynamomight be responsible for the observed magnetic activity on the mostactive, rapidly rotating stars.
| The Wilson-Bappu relation for RS CVn stars
We investigate the extent to which the Wilson-Bappu relationship holdsfor chromospherically active binaries using the Mg ii h&k lines of41 RS CVn stars observed with IUE. The resulting fits are different fromthe relationships obtained for single, less active stars. The parallaxused were those from the hipparcos catalogue, these give a much bettercorrelation than the magnitudes taken from CABS. Within a particularluminosity class the relationship is good, however it tends to breakdown when we incorporate objects ranging in luminosity from class i tov. From model calculations there is very little dependence of the Mg iiline width on effective temperature. The line width does however dependon the column mass at the transition region boundary showing increasedline width at lower column mass. There is also a dependence on thecolumn mass adopted for the temperature minimum, however, the major anddominant parameter is the surface gravity scaling as g(-1/4) . Within aluminosity class more active objects will show larger lines widthsreflecting a higher column mass deeper in the atmosphere, e.g. at thetemperature minimum level.
| Optical Positions of 44 Radio Stars from Astrolabe Observations
The observations made with the photoelectric astrolabe at YunnanObservatory since 1986 have been reprocessed in the Hipparcos Catalogue,and the optical positions of 44 radio stars obtained. These are all thestars in common with the Hipparcos Catalogue.
| Absolute declinations with the photoelectric astrolabe at Calern Observatory (OCA)
A regular observational programme with a photoelectric astrolabe havebeen performed at ``Observatoire du Calern" (Observatoire de laCôte d'Azur, OCA, phi = +43() o44′55.011″; lambda =-0() h27() m42.44() s, Calern, Caussols, France) for the last twentyyears. It has been almost fully automatized between 1984 and 1987. Since1988 the photoelectric astrolabe was used without any modification. Inaddition to determining the daily orientation of the local vertical, theyearly analysis of the residuals permits to derive corrections to theused star catalogue \cite[(Vigouroux et al. 1992)]{vig92}. A globalreduction method was applied for the ASPHO observations. The new form ofthe equations \cite[(Martin & Leister 1997)]{mar97} give us thepossibility of using the entire set of the observing program using datataken at two zenith distances (30() o and 45() o). The program containsabout 41648 stars' transits of 269 different stars taken at``Observatoire du Calern" (OCA). The reduction was based on theHIPPARCOS system. We discuss the possibility of computing absolutedeclinations through stars belonging simultaneously to the 30() o and45() o zenith distances programmes. The absolute declination correctionswere determined for 185 stars with precision of 0.027arcsec and thevalue of the determined equator correction is -0.018arcsec +/-0.005arcsec . The instrumental effects were also determined. The meanepoch is 1995.29. Catalogue only available at CDS in electronic from viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| Photometry and spectroscopy of the RS CVn system sigma Geminorum.
We present new UBV photoelectric photometry and high-resolutionH_α spectroscopy of the RS CVn system sigma Gem made in 1993-1994.A brief photometric analysis for the new light curves is carried outusing the Wilson-Devinney method with spot approximation based on theRoche model. The result suggests the probable presence of two cool spotson the K1 III primary around the phases of phi =0.6 and phi =0.9. Thespot activity is discussed in connection with the chromosphericH_α emission. The enhanced H_α core emission is found tovary with phase and shows distinct anti-correlation with the spotregions. It may be an indication for the existence of plage regions onsigma Gem.
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| Csillagkép: | Herkules |
| Rektaszcenzió: | 17h58m06.98s |
| Deklináció: | +15°08'21.9" |
| Vizuális fényesség: | 7.282 |
| Távolság: | 98.328 parszek |
| RA sajátmozgás: | -25 |
| Dec sajátmozgás: | 74.6 |
| B-T magnitude: | 7.993 |
| V-T magnitude: | 7.341 |
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