目录
图像
上传图像
DSS Images Other Images
相关文章
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.
| Long-Term VRI Photometry of Pulsating Red Giants
We report up to 5000 days of VRI photometry, from a robotic photometrictelescope, of 37 pulsating red giants, namely: TV Psc, EG And, Z Psc, RZAnd, 4 Ori, RX Lep, η Gem, μ Gem, UW Lyn, ψ 1 Aur,V523 Mon, V614 Mon, HD 52690, Y Lyn, BC CMi, X Cnc, UX Lyn, RS Cnc, VYUMa, ST UMa, TU CVn, FS Com, 35 Com, SW Vir, 30 Her, α1 Her, V642 Her, R Lyr, HD 174621, V450 Aql, V1293 Aql,δ Sge, EU Del, V1070 Cyg, W Cyg, μ Cep, and ν Cep. V, R, andI variations are generally in phase. The length and density of the dataenable us to look for variations on time scales ranging from days toyears. We use both power-spectrum (Fourier) analysis, andautocorrelation analysis, as well as light-curve analysis; these threeapproaches are complementary. The variations range from regular toirregular but, in most of the stars, we find a period in the range of 20to 200 days which is probably due to low-order radial pulsation. In manyof the stars, we also find a period which is an order of magnitudelonger. It may be due to rotation, or it may be due to a new kind ofconvectively-induced oscillatory thermal mode, recently proposed byPeter Wood. Supported by NASA, NSF, and NSERC Canada.
| Active eclipsing binary RT Andromedae revisited
All available photometric and spectroscopic data of the short-period RSCVn-like binary RT And have been reanalyzed in a homogeneous way. Thelong-term orbital period change is explained by two period jumps, acontinuous period decrease combined with the light-time orbit or twolight-time orbits. UBVRIJK light curves without maculation effectstogether with the radial velocities of both components were analysedwith the Wilson-Devinney program to compute the photometric andspectroscopic elements and derive the masses of the components:m1 = 1.10+/-0.02 Msun and m2 =0.83+/-0.02 Msun. The high orbital inclination i = 87.6degr+/- 0.1degr was confirmed by photoelectric observations of the secondaryminimum. The mean observed U light curve shows additional light duringthe secondary minimum. The small eccentricity found by several authorsfrom the light-curve analysis cannot be ruled out. The face-to-faceposition of the spots on the surface of both components in 1971indicates the possibility of a mass transfer from the primary to thesecondary component through a magnetic bridge connecting both activeregions. Analysis of all available light curves suggests a randomposition of starspots and does not confirm the idea of active longitudebelts. The absolute parameters of the binary together with maximalapparent V brightness set the distance of RT And to 83+/-2 pc, close tothe Hipparcos value of 75+/-6 pc.
| Accurate Positions for Radio Stars as Determined from CCD Observations in the Extragalactic Reference Frame.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1997AJ....114.1679S&db_key=AST
| Stars Classified as Constant in the General Catalogue of Variable Stars, II
Photometric observations have been made of 36 stars classified as CST orCST: in the General Catalogue of Variable Stars. Six of these stars arefound to vary and three others were deemed possible variables. Of thecertain variables, two (MR Her and TY Sge) are red pulsators, one (V1585Cyg) is a rapid irregular variable, one is apparently a short periodCepheid-strip star (V432 Oph), one is an eclipsing binary (AQ Boo) andone is uncertain type (V351 Cyg). The stars we have observed as MR Herand TY Sge are the same ones which were identified on finding charts inthe discovery papers suggesting that these stars have intervals ofvariability and intervals of quiescence. V432 Oph is of special interestbecause our photometry indicates that it may be either a double modeCepheid or a peculiar long period RR Lyrae star depending on which of acouple of possible periods turns out to be correct. (SECTION: Stars)
| Infrared Light Curves and Absolute Parameters of the Active Binary RT Andromedae
Abstract image available at:http://adsabs.harvard.edu/abs/1995AJ....110.1376A
| Optical positions of 221 radio stars obtained with the Bordeaux automatic meridian circle
From 1984 to 1990 the Bordeaux automatic meridian circle was used todetermine accurate J2000 positions of 221 radio stars. The observationswere strictly differential, a convenient number of FK5 stars being usedeach night to calculate the instrumental parameters. The mean positionswere corrected for chromatic refraction and also for photocenter effectin the case of duplicity. The asymptotic accuracy is expected to beabout 0.05 arcsec for the Northern stars with a number of observationsgreater than 25. Mean position of 3C273B is also given from 35measurements obtained in the same conditions.
| An astrometric catalogue of radio stars
The first part is presented of a radio star catalog encompassing 186objects whose selection was guided by the priority criteria of theHipparchos Input Catalogue Consortium. Since these criteria are wellsuited to the need for linkage of ground-based optical systems to radioreference frames, this first selection is also considered a suitablebase for the catalog. Seventeen categories of stellar parameters arefurnished for each of the stars, including optical and radio positions,optical and radio parallax, radial velocity, type of variability, andoptical structure.
| Mitteilungen über veränderliche und verdächtige Sterne
Not Available
|
提交文章
相关链接
提交链接
下列团体成员
|
观测天体数据
目录:
|
INHABITED SKY
