Principal     To Survive in the Universe    
Services
    Why to Inhabit     Top Contributors     Astrofotografía     La Colección     Foro     Blog New!     FAQ     Login  
→ Adopt this star  

TYC 98-2440-1


Contenidos

Imágenes

Subir su imagen

DSS Images   Other Images


Artículos relacionados

The EXOSAT high Galactic latitude survey
This study presents a survey of serendipitous sources performed in thevery soft X-ray band (0.05-2.0 keV) using the Exosat imaging telescopes.It covers 783 sq deg of high Galactic latitude sky and includes 210serendipitous sources which define a complete (flux-limited) sample. Twohundred of the 210 detected sources are identified via extensive opticaland radio observations together with cross-correlations with catalogs ofknown objects. The log N-log S relation was found to be consistent withthat of the Einstein extended Medium-Sensitivity Survey (EMSS) and withthe 'Euclidean' value of 1.5. The normalization of the relation is astrong function of the assumed spectral slope of AGN. It is inferredfrom the consistency with the EMSS results that the average (energy)slope of extragalactic sources in the soft X-ray band is very steep(approximately 1.5). An analysis of the association between AGNdetection and Galactic N(H) also shows that the average slope is steepand inconsistent with the canonical value of 0.7.

Confirmation among visual multiples of an increase of AP stars with age
Open clusters with ages below certain threshold values contain no Apstars and those with greater ages contain numbers of Ap stars thatapparently increase with age. But in view of the few young clustersstudied, the data could also be interpreted in terms of randomdifferences in the frequencies of Ap stars between individual clusters,rather than an age effect. Data on 77 field visual multiple systems(that originated from many different clusters and associations) in whichthe primaries are O5-A1 stars and the secondaries occur in the absolutemagnitude range of the Ap stars were, therefore, obtained. Againspectral classification shows no Ap stars in systems with ages notgreater than 1,000,000 yr and a steady increase in Ap stars thereafter.The numerical agreement with the cluster data is good, confirming thatthe cluster data are exhibiting a real age effect.

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:05h02m00.75s
Declinación:+01°36'41.3"
Magnitud Aparente:7.698
Distancia:82.919 parsecs
Movimiento Propio en Ascensión Recta:-13.3
Movimiento Propio en Declinación:6.4
B-T magnitude:7.877
V-T magnitude:7.713

Catálogos y designaciones:
Nombres Propios
TYCHO-2 2000TYC 98-2440-1
USNO-A2.0USNO-A2 0900-01310583
HIPHIP 23421

→ Solicitar más catálogos y designaciones a VizieR