- Stellar rotation
- Distributions of rotational velocities for A-type stars
- Search for intrinsic slow rotators in A0-A1 type stars:
Recent work by Royer et al. (2007) shows a pronounced double peaked distribution of rotational velocities for A stars. While this is in accordance with previous findings the hitherto assumed explanation of the peak at low v sin i being due to chemically peculiar or binary stars cannot be maintained: all known peculiar stars had been excluded from the sample. Those stars of the peak belonging to the underlying distribution peaking at high v sin i must be seen nearly pole-on and can be detected from square-shaped line profiles. We propose to observe a sample of 21 stars in that low v sin i range at high resolution and S/N to determine which stars are truly rapid rotators and what sets the slow rotators apart in terms of abundances or other peculiarities. These stars will complete our sample observable from the northern hemisphere.
- Stellar populations