Chemically Tagging the HR 1614 Moving Group
We present abundances for a sample of F, G, and K dwarfs of the HR 1614moving group based on high-resolution, high signal-to-noise ratiospectra from the Anglo-Australian Telescope UCLES instrument. Our sampleincludes stars from Feltzing and Holmberg, as well as from Eggen.Abundances were derived for Na, Mg, Al, Si, Ca, Mn, Fe, Ni, Zr, Ba, Ce,Nd, and Eu. The α, Fe, and Fe-peak element abundances show abimodal distribution, with four stars having solar metallicities, whilethe remaining 14 stars are metal-rich, [Fe/H]>=0.25 dex. However, theabundances of these two groups converge for the heavier n-captureelements. Based on their photometry and kinematics, three of the fourdeviating stars are likely nonmembers or binaries. Although one starcannot be excluded on these grounds, we do expect low-levelcontamination from field stars within the HR 1614 moving group's rangeof magnitude, color, and space velocities. Disregarding these fourstars, the abundance scatter across the group members for all elementsis low. We find that there is an 80% probability that the intrinsicscatter does not exceed the following values: Fe, 0.01 dex; Na, 0.08dex; Mg, 0.02 dex; Al, 0.06 dex; Si, 0.02 dex; Ca, 0.02 dex; Mn, 0.01dex; Ni, 0.01 dex; Zr, 0.03 dex; Ba, 0.03 dex; Ce, 0.04 dex; Nd, 0.01dex; and Eu, 0.02 dex. The homogeneity of the HR 1614 group in age andabundance suggests that it is the remnant of a dispersed star-formingevent. Its kinematical coherence shows that such a dispersing systemneed not be significantly perturbed by external dynamical influencessuch as Galactic spiral structure or giant molecular clouds, at leastover a period of 2 Gyr.
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INHABITED SKY
