Open AccessIC 2602: a lithium depletion boundary age and new candidate low‐mass stellar members ★
Author(s) -
Dobbie P. D.,
Lodieu N.,
Sharp R. G.
Publication year - 2010
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2010.17355.x
Subject(s) - open cluster , physics , astrophysics , cluster (spacecraft) , boundary (topology) , sequence (biology) , brown dwarf , lithium (medication) , stellar classification , stars , mathematics , chemistry , medicine , mathematical analysis , endocrinology , biochemistry , computer science , programming language
We report the results from a photometric and spectroscopic survey of ∼1.4 deg 2 of the young open cluster IC 2602. Fourteen objects have been identified as having magnitudes, spectral types and radial velocities consistent with being probable or possible low‐mass stellar members of the cluster. We have used the observed location of the lithium depletion boundary in the sequence defined by these objects to place a new and improved constraint on the cluster age, τ= 46 +6 −5 Myr. This new determination is larger by a factor ∼1.3–1.8 than the majority of age estimates which have been obtained using the main‐sequence turn‐off or pre‐main‐sequence isochrone techniques. It is thus consistent with the trend indicated by the results of similar studies on other young open clusters. Based on this new age, we set a lower limit on the cluster mass function over the range M = 0.054 − 0.24 M ⊙ , d n /d M > 46 M −1 ⊙ . If the mass function of IC 2602 has a form similar to that of other young clusters and associations then future wide, deep surveys can expect to unearth at least a handful of brown dwarfs which could potentially serve as benchmark objects.