CD-62°1346: an extreme halo or hypervelocity CH star?
نویسندگان
چکیده
منابع مشابه
Mmt Hypervelocity Star Survey
We describe a new survey for unbound hypervelocity stars (HVSs), stars traveling with such extreme velocities that dynamical ejection from a massive black hole (MBH) is their most likely origin. We investigate the possible contribution of unbound runaway stars, and show that the physical properties of binaries constrain low mass runaways to bound velocities. We measure radial velocities for HVS...
متن کاملLithium abundance in a turnoff halo star on an extreme orbit
Context. The lithium abundance in turnoff stars of the old population of our Galaxy is remarkably constant in the metallicity interval −2.8 < [Fe/H] < −2.0, defining a plateau. The Li abundance of these turnoff stars is clearly lower than the abundance predicted by the primordial nucleosynthesis in the frame of the standard Big Bang nucleosynthesis. Different scenarios have been proposed for ex...
متن کاملHalo Star Lithium Depletion
The depletion of lithium during the pre-main sequence and main sequence phases of stellar evolution plays a crucial role in the comparison of the predictions of big bang nucleosynthesis with the abundances observed in halo stars. Previous work has indicated a wide range of possible depletion factors, ranging from minimal in standard (non-rotating) stellar models to as much as an order of magnit...
متن کاملHalo Star Evolution
The low mass, low metallicity stars which make up the halo are probably the simplest of all stars to model. However, there are several puzzling discrepancies between theory and observations. In this review, I will discuss a few problems which point to the need for improved stellar evolution models of halo stars. Observations of the surface abundance of Li provide a sensitive diagnostic of the i...
متن کاملHypervelocity Stars: From the Galactic Center to the Halo
Hypervelocity stars (HVS) traverse the Galaxy from the central black hole to the outer halo. We show that the Galactic potential within 200 pc acts as a high pass filter preventing low velocity HVS from reaching the halo. To trace the orbits of HVS throughout the Galaxy, we construct two forms of the potential which reasonably represent the observations in the range 5–10 pc, a simple sphericall...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2012
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361/201219122