Home     Sopravvivere Nell'Universo    
Services
    Perché adottare     Donatori     Astro Foto     La collezione     Forum     Blog New!     FAQ     Login  
→ Adopt this star  

HD 173239


Contenuti

Immagini

Carica la tua immagine

DSS Images   Other Images


Articoli relazionati

New periodic variables from the Hipparcos epoch photometry
Two selection statistics are used to extract new candidate periodicvariables from the epoch photometry of the Hipparcos catalogue. Theprimary selection criterion is a signal-to-noise ratio. The dependenceof this statistic on the number of observations is calibrated usingabout 30000 randomly permuted Hipparcos data sets. A significance levelof 0.1 per cent is used to extract a first batch of candidate variables.The second criterion requires that the optimal frequency be unaffectedif the data are de-trended by low-order polynomials. We find 2675 newcandidate periodic variables, of which the majority (2082) are from theHipparcos`unsolved' variables. Potential problems with theinterpretation of the data (e.g. aliasing) are discussed.

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

Sottometti un nuovo articolo


Link relazionati

  • - Nessun link trovato -
Sottometti un nuovo link


Membro dei seguenti gruppi:


Osservazione e dati astrometrici

Costellazione:Lira
Ascensione retta:18h43m01.51s
Declinazione:+31°08'08.2"
Magnitudine apparente:7.881
Distanza:261.78 parsec
Moto proprio RA:1.7
Moto proprio Dec:-4.2
B-T magnitude:7.81
V-T magnitude:7.876

Cataloghi e designazioni:
Nomi esatti
HD 1989HD 173239
TYCHO-2 2000TYC 2637-1342-1
USNO-A2.0USNO-A2 1200-09687950
HIPHIP 91790

→ Richiesta di ulteriori cataloghi da VizieR