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Публикации по объекту
UV flux distributions of γ Doradus stars
Context: It seems that the recently identified class of pulsating stars,the γ Dor type-variables, includes objects with different metalabundances and a large percentage of binaries. Aims: We looked forindicators of metal abundance peculiarities and stellar binarity in asample of 40 confirmed γ Dor stars. Methods: Absolute magnitudesfrom Hipparcos parallaxes and UV magnitudes, from the S2/S68 experimenton board the TD1 satellite, are retrieved from databases and comparedwith predicted values. A set of non variable normal stars is used tocheck the consistency of this analysis and also serve as referencestars. Results: Twenty-nine stars of the γ Dor star sample,which is 73% of it, are discovered having abnormal UV fluxes constantlyshowing UV flux excesses compared to those computed with the atmosphericparameters (Teff , log g, and metallicity) determined fromcalibration of the uvbyβ indices. The reason for this UV excess offlux at 196.5 nm and at 236.5 nm, which was previously known only for HD209295, cannot be ascribed to binarity alone. An extra source of UV fluxor less UV absorption - yet unknown - must be present.Tables 1-3 are only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/472/241
| Photometry and Spectroscopy of 11 γ Doradus Stars
We have used precise photometric and high-dispersion spectroscopicobservations to study 11 γ Doradus stars, 10 of them newlyconfirmed. Only five of these 11 γ Doradus stars appear to besingle; two are primaries of double-lined spectroscopic binaries, one isthe secondary of a double-lined binary, two are primaries of visualbinaries and, in the case of the double-lined binary (HD 86371), eitheror both components could be a pulsating γ Doradus star. We havedetermined a preliminary orbital period of 5.32 days for thedouble-lined binary HD 41547. Several of the stars show spectroscopicline-profile and low-amplitude radial velocity variability indicative ofpulsation. All 11 stars are photometrically variable with amplitudesbetween 4 and 94 mmag in Johnson B and periods between 0.38 and 1.86days. The 11 stars have between two and five independent periods. Thevariability at all periods approximates a sinusoid. We provide a newtabulation of all 66 γ Doradus stars confirmed to date and listsome of their properties. All are dwarfs or subgiants and lie within awell-defined region of the H-R diagram that overlaps the cool edge ofthe δ Scuti instability strip. Four of the new γ Doradusvariables from this paper also lie within the δ Scuti instabilitystrip but do not exhibit the additional higher frequency variabilitytypical of δ Scuti stars. Among the 66 confirmed γ Doradusvariables, we find no correlation between the period of the strongestpulsation mode and the (B-V) color index, absolute magnitude, orluminosity.
| Effective temperature scale and bolometric corrections from 2MASS photometry
We present a method to determine effective temperatures, angularsemi-diameters and bolometric corrections for population I and II FGKtype stars based on V and 2MASS IR photometry. Accurate calibration isaccomplished by using a sample of solar analogues, whose averagetemperature is assumed to be equal to the solar effective temperature of5777 K. By taking into account all possible sources of error we estimateassociated uncertainties to better than 1% in effective temperature andin the range 1.0-2.5% in angular semi-diameter for unreddened stars.Comparison of our new temperatures with other determinations extractedfrom the literature indicates, in general, remarkably good agreement.These results suggest that the effective temperaure scale of FGK starsis currently established with an accuracy better than 0.5%-1%. Theapplication of the method to a sample of 10 999 dwarfs in the Hipparcoscatalogue allows us to define temperature and bolometric correction (Kband) calibrations as a function of (V-K), [m/H] and log g. Bolometriccorrections in the V and K bands as a function of T_eff, [m/H] and log gare also given. We provide effective temperatures, angularsemi-diameters, radii and bolometric corrections in the V and K bandsfor the 10 999 FGK stars in our sample with the correspondinguncertainties.
| Multi-site, multi-technique survey of γ Doradus candidates. I. Spectroscopic results for 59 stars
We present the first results of a 2-year high-resolution spectroscopycampaign of 59 candidate γ Doradus stars which were mainlydiscovered from the HIPPARCOS astrometric mission. More than 60% of thestars present line profile variations which can be interpreted as due topulsation related to γ Doradus stars. For all stars we alsoderived the projected rotation velocity (up to more than 200 kms-1). The amplitude ratios 2K/Δ m for the mainHIPPARCOS frequency are in the range 35-96 kms-1,mag-1. About 50% of the candidates arepossible members of binary systems, with 20 stars being confirmedγ Doradus. At least 6 stars present composite spectra, and in allbut one case (for which only one spectrum could be obtained), the narrowcomponent shows line profile variations, pointing towards anuncomfortable situation if this narrow component originates from a shellsurrounding the star. This paper is the first of a series concerningmode identification using both photometric and spectroscopic methods forthe confirmed γ Doradus stars of the present sample.Partially based on observations obtained at the Observatoire deHaute-Provence.
| A Dozen New γ Doradus Stars
We use new high-dispersion spectroscopic and precise photometricobservations to identify 12 new γ Doradus stars. Two of the 12systems are double-lined binaries that show obvious velocityvariability. Five other stars have metallic lines with compositeprofiles characterized by a narrow feature near the center of each broadcomponent. Spectrograms of the Hα line indicate that all fivestars are binaries rather than shell stars. The remaining five stars inour sample are probably single. All 12 stars are photometricallyvariable with amplitudes between 6 and 87 mmag in Johnson B and periodsbetween 0.3 and 1.2 days. Four stars are monoperiodic; the rest havebetween two and five independent periods. The variability at all periodsapproximates a sinusoid. Although many of the stars lie within theδ Scuti instability strip, none exhibit the higher frequencyvariability seen in δ Scuti stars. We have increased the sample ofknown γ Doradus stars by 40% and revised the positions of a numberof variables in the H-R diagram by accounting for duplicity. Our list of42 confirmed γ Doradus variables gives some of their properties.All are dwarfs or subgiants and lie within a well-defined region of theH-R diagram that overlaps the cool edge of the δ Scuti instabilitystrip. We compare the observed location of the γ Doradus variableswith a recently published theoretical γ Doradus instability stripand find good agreement.
| A Theoretical γ Doradus Instability Strip
In this paper, we present the first theoretical γ Doradusinstability strip. We find that our model instability strip agrees verywell with the previously established, observationally based, instabilitystrip of Handler & Shobbrook. We stress, as do Guzik et al., thatthe convection zone depth plays the major role in the determination ofour instability strip. Once this depth becomes too deep or too shallow,the convection zone no longer allows for pulsational instability. Ourtheoretical γ Dor instability strip is bounded by ~6850 and 7360 Kat the red and blue edge, respectively, on the zero-age main sequenceand by ~6560 and 7000 K at the red and blue edge, respectively,approximately 2 mag more luminous. This theoretical strip, transformedto the observer's color-magnitude diagram, overlays the region wheremost of the 30 bona fide γ Dor stars are found.
| Six New γ Doradus Stars
We present high-resolution spectroscopy and precision photometry of sixnew γ Doradus stars, one of which was independently discovered byanother group. This brings the total number of confirmed γ Doradusvariables to 30. All six of these variables fall in the spectral classrange F0-F2 all but one are subgiants. The six stars have between oneand five photometric periods in the range 0.3-1.2 days. We find noevidence for higher frequency δ Scuti pulsations in any of thesesix stars. Our spectroscopic observations reveal HD 108100 to be thefirst confirmed γ Doradus variable with composite broad and narrowline profiles suggesting the presence of a circumstellar shell or disk.HD 221866 has the most asymmetric absorption lines of the six stars inthis paper and also the largest photometric amplitude. Most of the 30confirmed γ Doradus variables lie in a fairly tight region of theH-R diagram on or just above the main sequence that partially overlapsthe cool edge of the δ Scuti instability strip. However, threestars, including two of the new variables in this paper, are subgiantsthat lie well within the δ Scuti strip. Among the 30 confirmedγ Doradus variables, we find no correlation between thephotometric periods and intrinsic color, absolute magnitude, orluminosity.
| The multiperiodicity of the gamma Doradus stars HD 224945 and HD 224638 as detected from a multisite campaign
We discuss new photometric data collected on the gamma Dor variables HD224945 and HD 224638. Multiperiodicity was detected in both stars,thanks to the clear spectral window of a multisite campaign thatinvolved five observatories. HD 224945 shows the shortest period amongthe gamma Dor stars, i.e., 0.3330 d. The pulsation behaviour is verydifferent: HD 224945 displays a set of frequencies spread over aninterval much larger than that of HD 224638. We clearly found evidencefor amplitude variations in the excited modes by comparing data fromdifferent years. HD 224945 and HD 224638 are among the best examples ofgamma Dor stars that show multimode pulsations, which make them veryinteresting from an asteroseismological point of view. Based onobservations partially collected at ESO-La Silla (Proposals 54.E-018 and56.E-0308).
| Search for gamma Doradus variable stars in the Pleiades cluster
Photometric observations in the uvbybeta system of A-F type stars in thePleiades cluster have been performed in order to detect pulsatingvariable stars of gamma Doradus type in the lower part of the Cepheidinstability strip. In order to obtain more information about thebehaviour of the studied objects and to be able to distinguish betweenlong period variable and non-variable stars, two statistical methodshave been developed. Several of these stars show some type ofvariability but only two of the observed objects, H1284 and S29, can besafely classified as gamma Dor stars. Furthermore, these observationshave provided us with Strömgren and Hβ photometry,non-existing up to now for some of them, which permitted us to perform aphotometric study of the Pleiades cluster.
| Gamma Doradus Stars: Defining a New Class of Pulsating Variables
In this paper we describe a new class of pulsating stars, the prototypeof which is the bright, early, F-type dwarf gamma Doradus. These starstypically have between 1 and 5 periods ranging from 0.4 to 3 days withphotometric amplitudes up to 0.1 mag in Johnson V. The mechanism forthese observed variations is high-order, low-degree, nonradial,gravity-mode pulsation.
| The gamma DOR variable HR 8799: results from a multisite campaign
In this paper, we present the results of a multisite photometriccampaign devoted to the gamma Doradus type variable HR 8799. FromJohnson and Stromgren data, we were able to identify three independentfrequencies (f_1= 1.9791 cycle d^-1, f_2=1.7268 cycle d^-1 andf_3=1.6498 cycle d^-1) as well as another signal, which we are able toidentify as the coupling term between two of the frequencies(f_4=f_1-f_2=0.2479 cycle d^-1). These four frequencies are able toaccount for all of the observed variations down to the 1sigmasignificance level. We discuss another possible interpretation of thesefrequencies using a model of quasi-stochastic amplitude modulation. Inthis scenario, we are able to show that HR 8799 might be pulsating withtwo independent frequencies, one of which undergoes amplitude modulationsimilar to other gamma Dor objects. In addition, we discuss apreliminary mode identification based on the observed colour curves.Finally, 18 simultaneous, high-resolution echelle spectra were collectedon two nights and we qualitatively compare the radial velocities fromthese data with our photometry.
| Discovery and analysis of Gamma Doradus type pulsations in the F0 IV star HR 2740=QW PUP
We present multisite photometric observations of the F0 IV star HR2740=QW Pup that reveal it to be a Gamma Dor type variable pulsatingwith four frequencies: 1.0434, 0.9951, 1.1088 and 0.9019/d. These datawere obtained over a time baseline spanning from January 14 to February11, 1997. The 1.0434/d term dominates in amplitude (10 mmag) over theother three (each less than 5 mmag); the light curve comprising thesefour frequencies seems to be very stable and no residual power is leftin the power spectrum. During the analysis particular attention was paidto methodological aspects, which cannot be neglected considering theproximity of the frequencies to 1/d. Physical parameters were alsoderived for all the well-known Gamma Dor stars, confirming that thisclass is very homogenous. In the framework of the campaign, two Ap starswere also observed. The photometric differences between these rotatingvariables and HR 2740 are emphasized, corroborating the pulsationalnature of the Gamma Dor stars. It is further demonstrated that therotational splitting cannot be a suitable explanation of the observedfrequency content of HR 2740.
| The Gamma DOR variable HD 164615 - Results from a multisite photometric campaign
We present the results from a multisite photometric campaign devoted tothe Gamma Dor variable HD 164615. During the campaign, data werecollected in the Johnson and Stromgren photometric systems. A firstsearch for sinusoidal periodicities yielded a three-term solution withfrequencies f1 = 1.2328, f2 = 1.0899, and f3 = 2.3501/d, and a long-termtrend f4 = 0.1301/d. The star may therefore be multiperiodic with eachfrequency related to a pulsation mode. However, a further examination ofthe curve provided evidence that the amplitude at the instant of maximumbrightness is modulated. Alternatively, HD 164615 may be a monoperiodicvariable with frequency f1 = 1.2321/d, showing amplitude modulation withfrequency f4 = 0.1301/d. The presence in the power spectra of thecoupling terms f2 = f1 - f4 and f3 = f1 + f4 - 1 supports the latterinterpretation. In the monoperiodic case the previously giveninterpretation based on a spot carried through the visible disk byrotation still holds, provided that the spot is bright and evolves on atime scale of a few days. However, similarities with other Gamma Dorstars provide indirect indication in favor of the existence of anonradial pulsation interpretation.
| The gamma Doradus-type variable 9 Aurigae: results from a multi-site campaign
We present the results of a multi-longitude coordinated photometriccampaign on the gamma Dor variable 9 Aur. Three frequencies can bedetermined from the data (f_1=0.7948, f_3=0.7679, f_5=0.3429 d^-1) twoof them have already been recognized in past seasons while the thirdfrequency is reported for the first time. Analysis shows that the thirdwas `turned off' or present with an amplitude below the limits ofdetection during previous observing seasons. This evidence, togetherwith consistent amplitude changes in the two previously recognizedsignals, suggests that the stellar structure responsible for 9 Aur'svariability is extremely dynamic. Intermediate-resolution spectra andCORAVEL radial velocities collected simultaneously show variability ontime-scales commensurable with the photometry. The only sensibleexplanation appears to be a non-radial pulsation (NRP) model. However,results obtained reveal a number of features that deviate from classicalNRP behaviour. Such features are emphasized in this paper in support ofthe future development of a specific NRP model - a model which has yetto be elucidated for gamma Dor-type variables.
| Convection, Thermal Bifurcation, and the Colors of A Stars
Broadband ultraviolet photometry from the TD-1 satellite andlow-dispersion spectra from the short wavelength camera of IUE have beenused to investigate a long-standing proposal of Bohm-Vitense that thenormal main-sequence A and early-F stars may divide into two differenttemperature sequences: (1) a high-temperature branch (and plateau)comprised of slowly rotating convective stars, and (2) a low-temperaturebranch populated by rapidly rotating radiative stars. We find noevidence from either data set to support such a claim, or to confirm theexistence of an "A-star gap" in the B-V color range 0.22 <= B-V <=0.28 due to the sudden onset of convection. We do observe, nonetheless,a large scatter in the 1800--2000 A colors of the A--F stars, whichamounts to ~0.65 mag at a given B-V color index. The scatter is notcaused by interstellar or circumstellar reddening. A convincing case canalso be made against binarity and intrinsic variability due topulsations of delta Sct origin. We find no correlation with establishedchromospheric and coronal proxies of convection, and thus nodemonstrable link to the possible onset of convection among the A--Fstars. The scatter is not instrumental. Approximately 0.4 mag of thescatter is shown to arise from individual differences in surface gravityas well as a moderate spread (factor of ~3) in heavy metal abundance andUV line blanketing. A dispersion of ~0.25 mag remains, which has noclear and obvious explanation. The most likely cause, we believe, is aresidual imprecision in our correction for the spread in metalabundances. However, the existing data do not rule out possiblecontributions from intrinsic stellar variability or from differential UVline blanketing effects owing to a dispersion in microturbulentvelocity.
| The 73rd Name-List of Variable Stars
Not Available
| γ Doradus and δ Scuti stars: cousins or twins?
γ Doradus stars are a group of slowly pulsating early F dwarfswith typical low frequencies near 1c/d. The pulsation modes are probablyg modes. These stars are slightly cooler than the typical δ Scutivariables, which pulsate with higher frequencies of typically 10c/d(mostly nonradial p modes). This paper examines the relationship betweenthe two groups of variables. Additional low-frequency variability hasbeen reported for fewer than 10% of the 300 δ Scuti starsexamined. In at least one case (1 Mon), the observational data areconsistent with an alternate interpretation in terms of a modeinteraction, f_1_-f_2_, between two p modes of higher frequency, ratherthan by the excitation of g modes. In several other stars (e.g. 4 CVn),the reported low-frequency variability may originate in the comparisonstar used. Arguments are given that for a number of stars the observedlow-frequency variations are caused by observational errors (such asinstrumental drift and transparency variations). A few δ Scutistars remain for which intrinsic γ Doradus-type variability mayalready have been discovered, although no case is well-studied. One ofthe best candidates is the star BI CMi, which is situated in the smallregion of overlap of the two groups of pulsators in theHertzsprung-Russell diagram. The star deserves further study.
| Mode identification of the slowly pulsating F0V star V398 Aurigae (9 Aur).
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996MNRAS.278..877A&db_key=AST
| A Search for Gamma-Doradus Type Variable Stars in the Hyades
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1995MNRAS.277.1404K&db_key=AST
| Multi-longitude campaigns on gamma Doradus stars
gamma Doradus stars constitute a new class of variables (Krisciunas1995). They have spectral types near F0 V and are variable up to 0.10mag in V on time scales of 0.5 to 3 days. Krisciunas & Handler(1995) list 17 bona fide examples and candidates. The mechanism forvariability appears to be non-radial gravity mode pulsations. Thisconclusion derives from the time scale of the variability (an order ofmagnitude longer than the fundamental radial pulsation period for starsof this density), radial velocity and spectral line profile variationsthat correlate with the photometric variations (Krisciunas et al. 1995;Balona et al. 199[6]), and lack of evidence for other explanations.Starspots are proposed by some (e.g. Zerbi 199[6]) as an alternativeexplanation to non-radial g-modes, but with at least 3 periods for twoof the stars and lack of evidence for chromospheric activity, we do notsee how the starspot idea is viable. Recently Aerts & Krisciunas(199[6]) and Balona et al. (199[6]) have identified the pulsation modesof two stars, V398 Aur (= 9 Aur) and gamma Doradus itself. In thisposter we present results of multi-longitude campaigns carried out fromNovember 1994 through October 1995 on gamma Dor, V398 Aur, HD 164615, BS8799, HD 224638, and HD 224945. Multi-longitude campaigns are necessaryfor the proper identification of the frequencies of variation, owing toaliasing that results from observations, at a single site, of stars withperiods on the order of one day. Aerts C., Krisciunas K., 199[6], MNRAS,in press Balona L. A. et al. 199[6], MUSICOS conference proceedings, inpress Krisciunas K., 1995, ``What is known and not known about gammaDoradus stars,'' Delta Scuti Star Newsletter, Issue 9, 17 Krisciunas K.et al. \ 1995, MNRAS, 273, 662 Krisciunas K., Handler G., 1995, IBVS4195 Zerbi F. M., 199[6], Vienna meeting on Stellar Surface Structure,IAU Symposium 176, in press
| The complex photometric behaviour of the δ Scuti star HD 224639.
HD 224639 was photometrically observed for 20h in 1989 and 120h in 1991(454 and 2567 datapoints, respectively). The star shows a very complexpulsational content with 3 components with semi-amplitudes of about15mmag and many other terms with a smaller semi-amplitude. The 1991dataset allowed us to single out 11 components in the frequency rangebetween 5 and 12 c/d, but many more are probably present since theresidual rms of the fit is 8.6mmag, while the noise level is expected tobe 3.7mmag. By subdividing the 1991 dataset into two parts and bycomparing the results of the frequency analysis with those obtained fromthe 1989 dataset we found independent evidence in support of thereliability of four frequencies: 6.21, 8.49, 9.54 and 11.42 c/d. Sincemost of the 11 components are nonradial modes, their identification ishampered by the high rotational velocity (vsin i=110km/s) which veryprobably produces the splitting of an l mode into a multiplet(-l<=m<=+l) and, in any case, causes an appreciable shift infrequency of the central value (m=0).
| Young Pulsating Stars in the Bohm-Vitense Decrement
Not Available
| A List of Variable Stars Similar to gamma Dor
Not Available
| 9 Aurigae: strong evidence for non-radial pulsations
We present further photometric observations of the unusual F0 V star 9Aurigae and present evidence that this star's radial velocity,spectroscopic line widths and line depths are also variable with thesame frequencies as the photometric data (f_1~=0.795 and f_2~=0.345d^-1). The phases of these sinusoids are stable over time-scales oflonger than one year, though the amplitudes can vary, making theprediction of photometric behaviour impossible. Given that a variety ofother explanations have already been discounted (e.g. interactions witha close companion, the existence of a lumpy, orbiting ring of dust, orstar spots) and that these variations occur on time-scales an order ofmagnitude slower than the fundamental radial pulsation period, we havevery strong evidence that 9 Aurigae exhibits non-radial g-modepulsations. Since the power spectrum of the radial velocity data showsfrequency f_2 but does not clearly show f_1, the present data suggestthat f_2 is associated with a low-degree spherical harmonic L=1 or 2),while f_1 is associated with a higher degree harmonic. 9 Aurigae, alongwith such stars as gamma Doradus, HD 224638, HD 224945, and HD 164615,appears to constitute a new class of pulsating variables. These starsare to be found at or beyond the cool edge of the Cepheid instabilitystrip in the HR Diagram. Prior to this, only much hotter stars have beenshown to exhibit non-radial g-modes.
| A long period early F-type variable: HR8799
Not Available
| Gamma-Doradus - Evidence for a New Class of Pulsating Star
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1994MNRAS.270..905B&db_key=AST
| Unusual Variability among Early F-Type Stars - HD224638 and HD224945
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1994MNRAS.270..439M&db_key=AST
| Unusual Photospheric Activity in Stars of Spectral Type FO-F5
Not Available
| The sign of four : a new class of cool non-radially pulsating stars ?
In this paper we discuss four early F-type variable stars whose periodsare an order of magnitude slower than known pulsators of comparableluminosity. They cannot be stars undergoing simple radial pulsations.For one or more of these stars we can discount the possibility that thevariability is due to rotational modulation of star spots, interactionswith (or tidal distortions by) a close companion, or obscuration by arotating lumpy ring of dust orbiting the star. They are certainly noteclipsing binaries. The only possibility left seems to be non-radialpulsations, though this explanation involves difficulties of its own. Ifthey are indeed pulsating stars exhibiting non- radial gravity modes,they would be the first stars on the cool side of the Cepheidinstability strip in the Hertzsprung-Russell Diagram to be soidentified.
| A new class of pulsating stars
Until recently, no stars on the cool side of the Cepheid instabilitystrip in the HR diagram (with the possible exception of the Sun) havebeen suspected of exhibiting non-radial gravity modes. For example, 53Persei (Sp = B4 IV) has Teff ~ 16,000\ K and the DOV star PG1159-035 has Teff ~ 123,000\ K. The papers listed below (andreferences therein) present a dozen stars which are typically early Fstars of luminosity class V or IV-V and which are photometricallyvariable up to 0.1 magnitude, with periods ranging from 0.3 to 1.8 days(an order of magnitude slower than one would expect of stars of thisspectral type and luminosity class undergoing simple radial pulsations).9 Aurigae (Sp = F0 V, Teff ~ 7200\ K, per = 1.277 days) hasshown evidence of radial velocity variations of order 6 km/sec andpossible line profile variations. gamma Doradus, which has two periodsnear 0.75 days, has definitely shown line profile variations. For HD96008 the notion of rotational modulation is ruled out because itsphotometric period would imply an equatorial rotational speed of 330km/sec -- incompatible with its having sharp spectral lines. 9 Aurigaeand HD 224638 (Sp ~ F0, per = 1.47 days) have both shown sudden phaseshifts in their light curves. Having eliminated a number ofpossibilities for individual stars, I conclude that these stars areeither exhibiting non-radial g-modes, or we are confronted with acompletely new physical mechanism for producing light variations instars. We present preliminary results of ongoing observations of some ofthese stars. Antonello, E., and Mantegazza, L. 1986, Astron. Astrophys.164, 40. Balona, L. A. et al. 199[3], Monthly Not. R. A. S., in press.Krisciunas, K. et al. \ 1993, Monthly Not. R. A. S. \ 263, 781.Krisciunas, K. 1993, Comments on Astrophys. \ 17, no. 4, in press.Mantegazza, L. et al. \ 1991, IBVS 3612. Mantegazza, L., and Poretti, E.1991, IBVS 3690. Mantegazza, L. et al. \ 1993, in Inside the Stars, ASPConf. Series 40, 651.
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Группы:
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Наблюдательные данные и астрометрия
| Созвездие: | Рыбы |
| Прямое восхождение: | 23h59m35.04s |
| Склонение: | -01°50'59.7" |
| Видимая звёздная величина: | 7.487 |
| Расстояние: | 79.618 парсек |
| Собственное движение RA: | 150.4 |
| Собственное движение Dec: | 29.6 |
| B-T magnitude: | 7.843 |
| V-T magnitude: | 7.517 |
Каталоги и обозначения:
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