Natalie Stout Batalha
Observatório Nacional , Rio de Janeiro

Lab.  Nacional de Astrofísica

Observatório do Pico dos Dias


Instrumentos e Detetores

Distribuição de Tempo

Publicações com dados do OPD

Projeto Gemini

Projeto SOAR




Rotation and Activity at the ZAMS


We have long been familiar with the very simple and tidy rotational velocity distribution of main sequence stars as a function of spectral type. We have long suspected that the overall rotation rates, and activity indicators in the case of late-type stars, decrease with age. However, when we look at the rotational velocity distribution of late-type stars which have not yet reached the main sequence, we are rather surprised. The distribution for late-type stars on the zero-age main sequence is rather sloppy with a sizable percentage of inexplicable ultra-fast rotators. In this talk, I will discuss some of the mysteries regarding these stars and how Doppler imaging analysis can help us to answer some basic questions regarding their angular momentum evolution.