Principal     Comenzar     To Survive in the Universe    
Inhabited Sky
    News@Sky     Astrofotografía     La Colección     Foro     Blog New!     FAQ     Prensa     Login  

HD 287545


Contenidos

Imágenes

Subir su imagen

DSS Images   Other Images


Artículos relacionados

Herbig Ae/Be Stars in nearby OB Associations
We have carried out a study of the early-type stars in nearby OBassociations spanning an age range of ~3-16 Myr, with the aim ofdetermining the fraction of stars that belong to the Herbig Ae/Be class.We studied the B, A, and F stars in the nearby (<=500 pc) OBassociations Upper Scorpius, Perseus OB2, Lacerta OB1, and Orion OB1,with membership determined from Hipparcos data. We also included in ourstudy the early-type stars in the Trumpler 37 cluster, part of the CepOB2 association. We obtained spectra for 440 Hipparcos stars in theseassociations, from which we determined accurate spectral types, visualextinctions, effective temperatures, luminosities and masses, usingHipparcos photometry. Using colors corrected for reddening, we find thatthe Herbig Ae/Be stars and the classical Be (CBe) stars occupy clearlydifferent regions in the JHK diagram. Thus, we use the location on theJHK diagram, as well as the presence of emission lines and of strong 12μm flux relative to the visual, to identify the Herbig Ae/Be stars inthe associations. We find that the Herbig Ae/Be stars constitute a smallfraction of the early-type stellar population even in the youngerassociations. Comparing the data from associations with different agesand assuming that the near-infrared excess in the Herbig Ae/Be starsarises from optically thick dusty inner disks, we determined theevolution of the inner disk frequency with age. We find that the innerdisk frequency in the age range 3-10 Myr in intermediate-mass stars islower than that in the low-mass stars (<1 Msolar) inparticular, it is a factor of ~10 lower at ~3 Myr. This indicates thatthe timescales for disk evolution are much shorter in theintermediate-mass stars, which could be a consequence of more efficientmechanisms of inner disk dispersal (viscous evolution, dust growth, andsettling toward the midplane).

The Henry Draper Extension Charts: A catalogue of accurate positions, proper motions, magnitudes and spectral types of 86933 stars
The Henry Draper Extension Charts (HDEC), published in the form offinding charts, provide spectral classification for some 87000 starsmostly between 10th and 11th magnitude. This data, being highlyvaluable, as yet was practically unusable for modern computer-basedastronomy. An earlier pilot project (Roeser et al. 1991) demonstrated apossibility to convert this into a star catalogue, using measurements ofcartesian coordinates of stars on the charts and positions of theAstrographic Catalogue (AC) for subsequent identification. We presenthere a final HDEC catalogue comprising accurate positions, propermotions, magnitudes and spectral classes for 86933 stars of the HenryDraper Extension Charts.

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:Orión
Ascensión Recta:05h08m12.55s
Declinación:+01°08'36.3"
Magnitud Aparente:9.152
Movimiento Propio en Ascensión Recta:-4.8
Movimiento Propio en Declinación:2.9
B-T magnitude:10.51
V-T magnitude:9.265

Catálogos y designaciones:
Nombres Propios   (Edit)
HD 1989HD 287545
TYCHO-2 2000TYC 99-1545-1
USNO-A2.0USNO-A2 0900-01380097
HIPHIP 23907

→ Solicitar más catálogos y designaciones a VizieR