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Pulkovo compilation of radial velocities for 35495 stars in a common system.
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| The Vienna-KPNO search for Doppler-imaging candidate stars. I. A catalog of stellar-activity indicators for 1058 late-type Hipparcos stars
We present the results from a spectroscopic Ca ii H&K survey of 1058late-type stars selected from a color-limited subsample of the Hipparcoscatalog. Out of these 1058 stars, 371 stars were found to showsignificant H&K emission, most of them previously unknown; 23% withstrong emission, 36% with moderate emission, and 41% with weak emission.These spectra are used to determine absolute H&K emission-linefluxes, radial velocities, and equivalent widths of theluminosity-sensitive Sr ii line at 4077 Ä. Red-wavelengthspectroscopic and Strömgren y photometric follow-up observations ofthe 371 stars with H&K emission are used to additionally determinethe absolute Hα -core flux, the lithium abundance from the Li i6708 Å equivalent width, the rotational velocity vsin i, theradial velocity, and the light variations and its periodicity. Thelatter is interpreted as the stellar rotation period due to aninhomogeneous surface brightness distribution. 156 stars were found withphotometric periods between 0.29 and 64 days, 11 additional systemsshowed quasi-periodic variations possibly in excess of ~50 days. Further54 stars had variations but no unique period was found, and four starswere essentially constant. Altogether, 170 new variable stars werediscovered. Additionally, we found 17 new SB1 (plus 16 new candidates)and 19 new SB2 systems, as well as one definite and two possible new SB3systems. Finally, we present a list of 21 stars that we think are mostsuitable candidates for a detailed study with the Doppler-imagingtechnique. Tables A1--A3 are only available in electronic form at theCDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| Speckle interferometry of HIPPARCOS link stars
Speckle interferometry has been carried out on 39 stars that had beenselected as provisionally suitable for linking Hipparcos positionalmeasurements to an extragalactic reference frame by Space Telescope. TheImperial College, London, speckle interferometer and the autocorrelatoron the Anglo-Australian 3.9-m telescope are used. The result is thatabout 30 percent of the stars selected turned out to be confirmed orsuspected multiple stars in the range 0.03-0.7 arcsec.
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| Takýmyýldýz: | Irmak |
| Sað Açýklýk: | 04h15m46.86s |
| Yükselim: | -18°38'25.6" |
| Görünürdeki Parlaklýk: | 7.049 |
| Uzaklýk: | 173.611 parsek |
| özdevim Sað Açýklýk: | -4.1 |
| özdevim Yükselim: | 20.3 |
| B-T magnitude: | 8.288 |
| V-T magnitude: | 7.152 |
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