Home

About

Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network
FAQHELPSITE MAPCONTACT US


  Advanced Search  

 
Mon. Not. R. Astron. Soc. 000, 000--000 (0000) Printed 22 October 1997 (MN L A T E X style file v1.3) Metallicity and photospheric abundances in field K and M
 

Summary: Mon. Not. R. Astron. Soc. 000, 000--000 (0000) Printed 22 October 1997 (MN L A T E X style file v1.3)
Metallicity and photospheric abundances in field K and M
dwarfs.
M. Zboril 1 , P.B. Byrne 1 , W.R.J.R. Rolleston 2
1 Armagh Observatory, College Hill, Armagh, BT61 9DG
2 Queens University of Belfast, Belfast, BT7 1NN
22 October 1997
ABSTRACT
Elemental abundances in late type stars are of interest in several ways: they deter­
mine the location on HR diagram and therefore age determination of stars, atmospheric
structure in middle and upper photosphere. Especially in the case of chromospherically
active late type stars the question arises to what degree is mainly upper photosphere
influenced by nearby chromosphere. Analysing S/N 200 and \Delta–/– ¸20 000 data we
found mean metallicity index [M/H]=­0.2 for programme K and M field stars based on
analysis of spectra in the region 5500­9000 š A. We also found the CaI 6162 š A transition
as potentionally surface gravity indicator for K type stars. Given the chromospheric
activity interval 4:4 ! logFMgII ! 6:6 we did not find any chromospheric activity im­
pact onto photospheric and upper photospheric transitions. With derived metallicity
we confirmed Li abundance from our previous paper and thus its dependence on Mg II
chromospheric activity index. The nature of spectrum of active M type star Gl896A is

  

Source: Armagh Observatory

 

Collections: Physics