An ALMA survey of $\lambda$ Orionis disks: from supernovae to planet formation

TL;DR

This ALMA survey of $\\lambda$ Orionis disks investigates the impact of massive stars and supernovae on planet formation, revealing minimal effects on disk material and offering insights into planet-forming environments in evolved star clusters.

Contribution

First ALMA survey of $\\lambda$ Orionis disks examining supernova effects on planet formation in an OB cluster environment.

Findings

Massive stars and supernovae do not significantly reduce disk material.

Outlier disks may host companions that prolong disk lifetimes.

$\\lambda$ Orionis provides valuable insights into planet formation in cluster environments.

Abstract

Protoplanetary disk surveys by the Atacama Large Millimeter/sub-millimeter Array (ALMA) are now probing a range of environmental conditions, from low-mass star-forming regions like Lupus to massive OB clusters like $\sigma$ Orionis. Here we conduct an ALMA survey of protoplanetary disks in $\lambda$ Orionis, a ~5 Myr old OB cluster in Orion, with dust mass sensitivities comparable to the surveys of nearby regions (~0.4 $M_\oplus$). We assess how massive OB stars impact planet formation, in particular from the supernova that may have occurred ~1 Myr ago in the core of $\lambda$ Orionis; studying these effects is important as most planetary systems, including our Solar System, are likely born in cluster environments. We find that the effects of massive stars, in the form of pre-supernova feedback and/or a supernova itself, do not appear to significantly reduce the available planet-forming material otherwise expected at the evolved age of $\lambda$ Orionis. We also compare a lingering massive "outlier" disk in $\lambda$ Orionis to similar systems in other evolved regions, hypothesizing that these outliers host companions in their inner disks that suppress disk dispersal to extend the lifetimes of their outer primordial disks. We conclude with numerous avenues for future work, highlighting how $\lambda$ Orionis still has much to teach us about perhaps one of the most common types of planet-forming environments in the Galaxy.