Astronomy and Astrophysics – Astrophysics
Scientific paper
2006-03-13
Astron.J.131:2959-2966,2006
Astronomy and Astrophysics
Astrophysics
37 pages, 13 figures, 2 tables (1 large); accepted for publication in AJ
Scientific paper
10.1086/504156
The stellar group surrounding the Be (B1Vpe) star 25 Orionis was discovered to be a pre-main-sequence population by the Centro de Investigaciones de Astronomia (CIDA) Orion Variability Survey and subsequent spectroscopy. We analyze Sloan Digital Sky Survey multi-epoch photometry to map the southern extent of the 25 Ori group and to characterize its pre-main-sequence population. We compare this group to the neighboring Orion OB1a and OB1b subassociations and to active star formation sites (NGC 2068/NGC 2071) within the Lynds 1630 dark cloud. We find that the 25 Ori group has a radius of 1.4 degrees, corresponding to 8-11 pc at the distances of Orion OB1a and OB1b. Given that the characteristic sizes of young open clusters are a few pc or less this suggests that 25 Ori is an unbound association rather than an open cluster. Due to its PMS population having a low Classical T Tauri fraction (~10%) we conclude that the 25 Ori group is of comparable age to the 11 Myr Orion OB1a subassociation.
No associations
LandOfFree
The Southern Flanking Fields of the 25 Orionis Group does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The Southern Flanking Fields of the 25 Orionis Group, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Southern Flanking Fields of the 25 Orionis Group will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-69171