| |
 |
| Paper: |
The Sodium Doublets as Youth Indicators for Low-Mass Stars |
| Volume: |
448, 16th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun |
| Page: |
935 |
| Authors: |
Schlieder, J. E.; Fielding, D.; Lepine, S.; Rice, E.; Tomasino, R.; Simon, M.; Shara, M. M. |
| Abstract: |
We investigate the use of the Na I doublets at 5890 and 5896 Å (the
Fraunhofer D lines) and 8183 and 8195 Å as gravity indicators for stars of
late K and M spectral type. As is well known, the equivalent widths
(EWs) of these doublets increase with photospheric log(g). We show that the
EWs of members of the β Pictoris moving group (BPMG) (age 10-20 Myr) lie
between the EWs of giants and main sequence stars based on the analysis of
approx. 200 spectra collected with the MDM 1.3-meter McGraw-Hill telescope
and the SMARTS 1.5-meter telescope. We find the Na D lines are useful age
indicators for low mass BPMG candidates earlier than M2 and the 8200 Å
doublet becomes useful for stars later than M4. The EWs of the Na doublets
may therefore be used to establish low gravity, hence youth, among low mass
stars in general. |
|
|
|
|
|
