Contenidos
Imágenes
Subir su imagen
DSS Images Other Images
Artículos relacionados
Pulkovo compilation of radial velocities for 35495 stars in a common system.
Not Available
| Candidate Pre-Main-Sequence F Stars with Circumstellar Dust Identified Using Combined 2MASS and uvby Data
We propose a method that uses near-infrared plus uvby photometry toidentify potentially extensive circumstellar dusty environments around Fand A stars. The method has been applied to a sample of ~900 metal-richreddened F stars with 2 Micron All Sky Survey and uvby data, suggestingthe presence of circumstellar dust emitting in the near-infrared for ~70stars. The logTe-MV diagram suggests that most, ifnot all, are likely pre-main-sequence (PMS) stars. They seem to be acontinuation of the class of Herbig Ae/Be PMS stars in the spectral typeF. Their number drops sharply downward of logTe~3.84(spectral types later than ~F5), which may provide new clues to the PMSevolution of 1-2 Msolar stars. We present a list of 21 of themost conspicuous candidate stars with circumstellar dust. About half ofthem are associated with the extended star-forming region around ρOphiuchi. The brightest of these 21 stars, with V<~7.5, turn out tobe IRAS sources, suggesting the presence of heated dust emitting in thefar-infrared. Also in this list, HD 81270 is reported as a very unusualstar moving away from the Galactic plane at a projected speed of 70 kms-1.
| Radial velocities. Measurements of 2800 B2-F5 stars for HIPPARCOS
Radial velocities have been determined for a sample of 2930 B2-F5 stars,95% observed by the Hipparcos satellite in the north hemisphere and 80%without reliable radial velocity up to now. Observations were obtainedat the Observatoire de Haute Provence with a dispersion of 80Ä,mm(-1) with the aim of studying stellar and galactic dynamics.Radial velocities have been measured by correlation with templates ofthe same spectral class. The mean obtained precision is 3.0 km s(-1)with three observations. A new MK spectral classification is estimatedfor all stars. Based on observations made at the Haute ProvenceObservatory, France and on data from The Hipparcos Catalogue, ESA.Tables 4, 5 and 6 are only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr or viahttp://cdsweb.u-strasbg.fr/Abstract.htm
| Estimation of spectral classifications for bright northern stars with interesting Stromgren indices
The purpose of this investigation is to provide spectroscopic observerswith finding lists of potentially interesting objects. From anunpublished UVBY catalogue of 7026 northern stars (mostly brighter than8.3m) 1094 objects with interesting combinations of UVBY indices havebeen selected. Most stars with post-HD classifications have beenexcluded, as well as late F dwarfs belonging to the intermediatepopulation II. For the 792 remaining stars estimated spectralclassifications are given. The techniques and experience from a previouspaper dealing with southern stars have been utilized here. Among thepredicted spectral classifications are 40 OB stars; 262 Ap, Am, or Fmstars; 16 supergiants of types A to G; 110 bright giants of types A to K(class II); 156 double stars or objects with composite spectra; 26 lateF dwarfs; 91 weak-lined dwarf and giant stars of types F to K, includingearly F-type population II field blue stragglers; and a few possiblefield horizontal branch stars, lambda Bootis-type stars, and late-typehalo giants.
|
Enviar un nuevo artículo
Enlaces relacionados
- - No se han encontrado enlaces -
En viar un nuevo enlace
Miembro de los siguientes grupos:
|
Datos observacionales y astrométricos
| Constelación: | Andrómeda |
| Ascensión Recta: | 23h39m37.64s |
| Declinación: | +43°19'57.4" |
| Magnitud Aparente: | 7.57 |
| Distancia: | 231.481 parsecs |
| Movimiento Propio en Ascensión Recta: | 24.1 |
| Movimiento Propio en Declinación: | -0.8 |
| B-T magnitude: | 8.257 |
| V-T magnitude: | 7.627 |
Catálogos y designaciones:
|
INHABITED SKY
