Home     Evrende yaþayabilmek için    
Services
    Niçin Edinmelisiniz     En fazla Destek olanlar     Gökyüzü görüntüsü     Koleksiyon     Forum     Blog New!     SSS     Giriþ  
→ Adopt this star  

HD 168755


Ýçindekiler

Görüntüler

Resim Yükleyin

DSS Images   Other Images


Ýlgili Makaleler

H gamma and H delta Absorption Features in Stars and Stellar Populations
The H gamma and H delta absorption features are measured in a sample of455 (out of an original 460) Lick/IDS stars with pseudo--equivalentwidth indices. For each Balmer feature, two definitions, involving anarrow (~20 Angstroms) and a wide (~40 Angstroms) central bandpass, aremeasured. These four new Balmer indices augment 21 indices previouslydetermined by Worthey et al., and polynomial fitting functions that giveindex strengths as a function of stellar temperature, gravity, and[Fe/H] are provided. The new indices are folded into models for theintegrated light of stellar populations, and predictions are given forsingle-burst stellar populations of a variety of ages and metallicities.Contrary to our initial hopes, the indices cannot break a degeneracybetween burst age and burst strength in post-starburst objects, but theyare successful mean-age indicators when used with sensitive metallicityindicators. An appendix gives data, advice, and examples of how totransform new spectra to the 25-index Lick/IDS system.

Old stellar populations. 5: Absorption feature indices for the complete LICK/IDS sample of stars
Twenty-one optical absorption features, 11 of which have been previouslydefined, are automatically measured in a sample of 460 stars. FollowingGorgas et al., the indices are summarized in fitting functions that giveindex strengths as functions of stellar temperature, gravity, and(Fe/H). This project was carried out with the purpose of predictingindex strengths in the integrated light of stellar populations ofdifferent ages and metallicities, but the data should be valuable forstellar studies in the Galaxy as well. Several of the new indices appearto be promising indicators of metallicity for old stellar populations. Acomplete list of index data and atmospheric parameters is available incomputer-readable form.

Yeni bir Makale Öner


Ýlgili Baðlantýlar

  • - Baðlantý Bulunamadý -
Yeni Bir Baðlantý Öner


sonraki gruplarýn üyesi:


Gözlemler ve gökölçümü verileri

Takýmyýldýz:Guney Taci
Sað Açýklýk:18h23m19.11s
Yükselim:-42°46'47.9"
Görünürdeki Parlaklýk:8.935
Uzaklýk:98.522 parsek
özdevim Sað Açýklýk:-14.2
özdevim Yükselim:-81.7
B-T magnitude:9.467
V-T magnitude:8.979

Kataloglar ve belirtme:
Özgün isimleri
HD 1989HD 168755
TYCHO-2 2000TYC 7909-1656-1
HIPHIP 90109

→ VizieR 'den daha fazla katalog ve tanýmlama isteyin