2020ApJ...889...50Y

We have conducted a high-dispersion (R ∼ 34,000) optical spectroscopic study of 10 young stars near the cometary globule CG 30 in the Gum Nebula, a diffuse H II region home to at least 32 cometary globules. All 10 spectroscopically observed stars at the nebula's northern edge are of low mass (spectral types M4.5-K5), have broad Hα emission, and show spectral veiling. Eight of the 10 are classical T Tauri stars. We spectroscopically measure the photospheric properties of CG 30 IRS 4 inside CG 30. Though embedded, CG 30 IRS 4 is T Tauri-like, with relatively slow projected rotation and moderate veiling. Undepleted Li absorptions, strong Hα emissions, and positions well above the main sequence on an H-R diagram suggest that the 10 stars are <=1 Myr old. Using our measurements, previous spectroscopy, and previous photometry of 11 other young stars in the area, we determine stellar, kinematic, and accretion properties of a total of 21 young stars. Shared radial velocities, proper motions, distances, and ages suggest that 14 of the young stars (including CG 30 IRS 4) are kinematically related to CG 30. From Gaia DR2 distances to six of these stars, we derive a distance of 358.1 ± 2.2 pc to the cometary globule complex CG 30/31/38. The CG 30 association has an accretor fraction of 29% ± 14%, low for quiescent clusters of similar age but consistent with other irradiated clusters. The Gum Nebula's moderate radiation environment (G₀=6.6_–2.7^+3.2 at CG 30) may be strong enough to shorten disk lifetimes.