Ýçindekiler
Görüntüler
Resim Yükleyin
DSS Images Other Images
Ýlgili Makaleler
Spectroscopic stellar parameters for 582 FGK stars in the HARPS volume-limited sample. Revising the metallicity-planet correlation
To understand the formation and evolution of solar-type stars andplanets in the solar neighborhood, we need to obtain their stellarparameters with high precision. We present a catalog of precise stellarparameters for low-activity FGK single stars in a volume-limited samplefollowed by the HARPS spectrograph in the quest to identify extra-solarplanets. The spectroscopic analysis was completed assuming LTE with agrid of Kurucz atmosphere models and using the ARES code to perform anautomatic measurement of the line equivalent widths. The results arecompared with different independent methods and also with other valuesfound in the literature for common stars. Both comparisons areconsistent and illustrate the homogeneity of the parameters derived byour team. The derived metallicities of this sample reveal a somewhatdifferent distribution for the present planet hosts, but still indicatesthe already known higher frequency of planets observed for the moremetal-rich stars. We combine the results derived in this sample with theone from the CORALIE survey to present the largest homogeneousspectroscopic study of the metallicity-giant-planet relation using atotal of 1830 stars.Full Table 1 is only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/533/A141
| Improved Astrometry and Photometry for the Luyten Catalog. II. Faint Stars and the Revised Catalog
We complete construction of a catalog containing improved astrometry andnew optical/infrared photometry for the vast majority of NLTT starslying in the overlap of regions covered by POSS I and by the secondincremental Two Micron All Sky Survey (2MASS) release, approximately 44%of the sky. The epoch 2000 positions are typically accurate to 130 mas,the proper motions to 5.5 mas yr-1, and the V-J colors to0.25 mag. Relative proper motions of binary components are measured to 3mas yr-1. The false-identification rate is ~1% for11<~V<~18 and substantially less at brighter magnitudes. Theseimprovements permit the construction of a reduced proper-motion diagramthat, for the first time, allows one to classify NLTT stars intomain-sequence (MS) stars, subdwarfs (SDs), and white dwarfs (WDs). We inturn use this diagram to analyze the properties of both our catalog andthe NLTT catalog on which it is based. In sharp contrast to popularbelief, we find that NLTT incompleteness in the plane is almostcompletely concentrated in MS stars, and that SDs and WDs are detectedalmost uniformly over the sky δ>-33deg. Our catalogwill therefore provide a powerful tool to probe these populationsstatistically, as well as to reliably identify individual SDs and WDs.
| The general catalogue of trigonometric [stellar] paralaxes
Not Available
|
Yeni bir Makale Öner
Ýlgili Baðlantýlar
Yeni Bir Baðlantý Öner
sonraki gruplarýn üyesi:
|
Gözlemler ve gökölçümü verileri
| Takýmyýldýz: | Agcik |
| Sað Açýklýk: | 03h20m46.65s |
| Yükselim: | -62°16'28.1" |
| Görünürdeki Parlaklýk: | 9.951 |
| özdevim Sað Açýklýk: | 268.7 |
| özdevim Yükselim: | 29.7 |
| B-T magnitude: | 10.898 |
| V-T magnitude: | 10.03 |
Kataloglar ve belirtme:
|
INHABITED SKY
