Inici     Començant     Sobreviure a l'Univers    
Inhabited Sky
    News@Sky     Astro Fotografia     La Col·lecció     Fòrum     Blog New!     FAQ     Premsa     Login  

HD 189540


Contingut

Imatges

Carregar la teva Imatge

DSS Images   Other Images


Articles Relacionats

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.

Enviar un nou article


Enllaços Relacionats

  • - No s'ha trobat enllaços -
Enviar un nou enllaç


Membre dels grups següents:


Dades d'Observació i Astrometria

Constel·lació:Sagittarius
Ascensió Recta:20h01m13.56s
Declinació:-21°33'34.5"
Magnitud Aparent:9.308
Moviment propi RA:109
Moviment propi Dec:-133.8
B-T magnitude:10.159
V-T magnitude:9.379

Catàlegs i designacions:
Noms Propis   (Edit)
HD 1989HD 189540
TYCHO-2 2000TYC 6326-752-1
USNO-A2.0USNO-A2 0675-34737789
HIPHIP 98559

→ Sol·licitar més catàlegs i designacions de VizieR