Photometric identification of the low-mass population of orion OB1b. I. The σ orionis cluster

W. H. Sherry; F. M. Walter; S. J. Wolk

doi:10.1086/424863

Photometric identification of the low-mass population of orion OB1b. I. The σ orionis cluster

W. H. Sherry
, F. M. Walter
, S. J. Wolk

Physics and Astronomy

Stony Brook University
Harvard-Smithsonian Ctr. Astrophys.

Research output: Contribution to journal › Article › peer-review

97 Scopus citations

Abstract

We report an optical photometric survey of 0.89 deg ² of the Orion OB1b association centered on σ Ori. This region includes most of the σ Ori cluster, the highest-density region within Orion OB1b. We have developed a statistical procedure to identify the young, low-mass, pre-main-sequence population of the association. We estimate that the cluster has ∼160 members in the mass range (0.2 ≤ M ≤ 1.0 M _⊙). The cluster has a radius of ∼3-5 pc and an estimated age of 2.5 ± 0.3 Myr. We estimate that the total mass of the cluster is 225 ± 30 M _⊙. This mass is similar to the estimated mass of the ∼5 × 10 ⁵ yr old cluster NGC 2024. NGC 2024 and σ Ori appear to be a well-matched pair of clusters, except for the ∼2 Myr difference in their ages.

Original language	English
Pages (from-to)	2316-2330
Number of pages	15
Journal	Astronomical Journal
Volume	128
Issue number	5
DOIs	https://doi.org/10.1086/424863
State	Published - Nov 2004

Keywords

Open clusters and associations: individual (σ Orionis)
Stars: formation
Stars: imaging
Stars: low-mass, brown dwarfs
Stars: pre-main-sequence

Access to Document

10.1086/424863

Cite this

@article{724508e8a8114b83a728abcb5c1bb43a,

title = "Photometric identification of the low-mass population of orion OB1b. I. The σ orionis cluster",

abstract = "We report an optical photometric survey of 0.89 deg 2 of the Orion OB1b association centered on σ Ori. This region includes most of the σ Ori cluster, the highest-density region within Orion OB1b. We have developed a statistical procedure to identify the young, low-mass, pre-main-sequence population of the association. We estimate that the cluster has ∼160 members in the mass range (0.2 ≤ M ≤ 1.0 M ⊙). The cluster has a radius of ∼3-5 pc and an estimated age of 2.5 ± 0.3 Myr. We estimate that the total mass of the cluster is 225 ± 30 M ⊙. This mass is similar to the estimated mass of the ∼5 × 10 5 yr old cluster NGC 2024. NGC 2024 and σ Ori appear to be a well-matched pair of clusters, except for the ∼2 Myr difference in their ages.",

keywords = "Open clusters and associations: individual (σ Orionis), Stars: formation, Stars: imaging, Stars: low-mass, brown dwarfs, Stars: pre-main-sequence",

author = "Sherry, \{W. H.\} and Walter, \{F. M.\} and Wolk, \{S. J.\}",

year = "2004",

month = nov,

doi = "10.1086/424863",

language = "English",

volume = "128",

pages = "2316--2330",

journal = "Astronomical Journal",

issn = "0004-6256",

number = "5",

}

TY - JOUR

T1 - Photometric identification of the low-mass population of orion OB1b. I. The σ orionis cluster

AU - Sherry, W. H.

AU - Walter, F. M.

AU - Wolk, S. J.

PY - 2004/11

Y1 - 2004/11

N2 - We report an optical photometric survey of 0.89 deg 2 of the Orion OB1b association centered on σ Ori. This region includes most of the σ Ori cluster, the highest-density region within Orion OB1b. We have developed a statistical procedure to identify the young, low-mass, pre-main-sequence population of the association. We estimate that the cluster has ∼160 members in the mass range (0.2 ≤ M ≤ 1.0 M ⊙). The cluster has a radius of ∼3-5 pc and an estimated age of 2.5 ± 0.3 Myr. We estimate that the total mass of the cluster is 225 ± 30 M ⊙. This mass is similar to the estimated mass of the ∼5 × 10 5 yr old cluster NGC 2024. NGC 2024 and σ Ori appear to be a well-matched pair of clusters, except for the ∼2 Myr difference in their ages.

AB - We report an optical photometric survey of 0.89 deg 2 of the Orion OB1b association centered on σ Ori. This region includes most of the σ Ori cluster, the highest-density region within Orion OB1b. We have developed a statistical procedure to identify the young, low-mass, pre-main-sequence population of the association. We estimate that the cluster has ∼160 members in the mass range (0.2 ≤ M ≤ 1.0 M ⊙). The cluster has a radius of ∼3-5 pc and an estimated age of 2.5 ± 0.3 Myr. We estimate that the total mass of the cluster is 225 ± 30 M ⊙. This mass is similar to the estimated mass of the ∼5 × 10 5 yr old cluster NGC 2024. NGC 2024 and σ Ori appear to be a well-matched pair of clusters, except for the ∼2 Myr difference in their ages.

KW - Open clusters and associations: individual (σ Orionis)

KW - Stars: formation

KW - Stars: imaging

KW - Stars: low-mass, brown dwarfs

KW - Stars: pre-main-sequence

UR - https://www.scopus.com/pages/publications/10844237262

U2 - 10.1086/424863

DO - 10.1086/424863

M3 - Article

AN - SCOPUS:10844237262

SN - 0004-6256

VL - 128

SP - 2316

EP - 2330

JO - Astronomical Journal

JF - Astronomical Journal

IS - 5

ER -

Photometric identification of the low-mass population of orion OB1b. I. The σ orionis cluster

Abstract

Keywords

Access to Document

Other files and links

Cite this