Very Low‐Mass Stars and Brown Dwarfs of the Young Open Cluster IC 2391

Abstract

We have identified a large sample of probable low-mass members of the young open cluster IC 2391 based on optical (VRIZ) and infrared (JHKs) photometry. Our sample includes 50 probable members and 82 possible members, both very low-mass stars and brown dwarfs. We also provide accurate positions for these stars and brown dwarf candidates derived from red UK Schmidt plates measured using the microdensitometer SuperCOSMOS. Assuming an age of 53 Myr, we estimate that we have reached a mass of 0.025 Msolar, if the identified objects are indeed members of IC 2391. Based on observations obtained at the Cerro Tololo Inter-American Observatory.