Emergence of a lithium dip in ~35 Myr “Snake” Open Clusters
Yun-Yi Zhang, Hai-Jun Tian, Jian-Rong Shi, Cheng-Cheng Xie, Xiang-Ming Yang
arXiv:2602.07367v1 Announce Type: new
Abstract: We report the discovery of a lithium dip (Li-dip) in the stellar “Snake” (age = $35 pm 5$ Myr), challenging the classical view that Li-dips emerge only at ages $gtrsim 150$ Myr. Using high-resolution spectra from GALAH DR4 ($R sim 28,000$) for 211 member stars, we identify a clear depletion feature in a $T_{mathrm{eff}}$ range of 6200–6800 K with a depth of $Delta A(mathrm{Li}) approx 0.40$ dex. Our analysis reveals two key advances: the Li-dip appears $gtrsim 100$ Myr earlier than the previous observations, and within the dip temperature range, a significant correlation is found between rotational velocity and lithium depletion. Specifically, fast rotators ($v sin i > 25$ km s$^{-1}$) exhibit stronger lithium depletion than slow rotators ($v sin i arXiv:2602.07367v1 Announce Type: new
Abstract: We report the discovery of a lithium dip (Li-dip) in the stellar “Snake” (age = $35 pm 5$ Myr), challenging the classical view that Li-dips emerge only at ages $gtrsim 150$ Myr. Using high-resolution spectra from GALAH DR4 ($R sim 28,000$) for 211 member stars, we identify a clear depletion feature in a $T_{mathrm{eff}}$ range of 6200–6800 K with a depth of $Delta A(mathrm{Li}) approx 0.40$ dex. Our analysis reveals two key advances: the Li-dip appears $gtrsim 100$ Myr earlier than the previous observations, and within the dip temperature range, a significant correlation is found between rotational velocity and lithium depletion. Specifically, fast rotators ($v sin i > 25$ km s$^{-1}$) exhibit stronger lithium depletion than slow rotators ($v sin i