html5-img
1 / 17

Spectrophotometric properties of the nearest pre-main sequence stars

Spectrophotometric properties of the nearest pre-main sequence stars. 2009. 10. 07 A-Ran Lyo. HR diagram. Pre-main sequence. Luminosity. Temperature. H α emission line : accretion disk & chromospheric activity

hester
Download Presentation

Spectrophotometric properties of the nearest pre-main sequence stars

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Spectrophotometric properties of the nearest pre-main sequence stars 2009. 10. 07 A-Ran Lyo

  2. HR diagram Pre-main sequence Luminosity Temperature

  3. Hα emission line : accretion disk & chromospheric activity • Li I absorption line : age indicator because Li I is diminished fast during the very early phase of stellar evolution. Lyo et al. 2004a

  4. ε Chamaelentis cluster : t = 3 - 5 Myr (Feigelson et al. 2003) • ~ 6 Myr (Luhman 2004) • η Cha cluster : t = 5 - 8 Myr (Luhman & Steeghs 2004) • = 7 - 9 Myr (Lyo et al. 2004) • TW Hydrae association : t ~ 8 - 10 Myr (Webb et al. 1999) • β Pictoris Moving group : t ~ 20±10 Myr (Barrado y Navascues 2001) • Lower Centaurus Crux : t = 17 ~ 23 Myr (Mamajek etal. 2002) • a common kinematic link with the Ophiuchus-Scorpius- • Centaurus OB Association

  5. Pre-main sequence evolutionary models Lawson & Feigelson 2000

  6. Spectral lines : Effective temperature (spectral type) : Luminosity (surface gravity) : Chemical composition (metallicity) valuable input for understanding PMS stellar structure and evolution.

  7.  Chamaeleontis

  8. η Chamaeleontis Lyo et al. 2004b

  9. Comparison of η Cha cluster members and dwarfs PC3 PC4 PC5 TiO CaH CaOH Lyo et al. 2004b

  10. Temperature-sensitive indices Lyo et al. 2004b

  11. Gravity-sensitive indices Lyo et al. 2004b

  12. Lyo et al. 2008

  13. Lawson, Lyo, & Bessell 2009, accepted

  14. Lawson, Lyo, & Bessell 2009, accepted

  15. Thank you

More Related