A Tale of Three Cities: OmegaCAM discovers multiple sequences in the color-magnitude diagram of the Orion Nebula Cluster

  • G. Beccari
  • , M.G. Petr-Gotzens
  • , H.M.J. Boffin
  • , M. Romaniello
  • , D. Fedele
  • , G. Carraro
  • , G. De Marchi
  • , W.J. de Wit
  • , J. E. Drew
  • , V. M. Kalari
  • , Carlo Felice Manara
  • , Eduardo L. Martin
  • , S. Mieske
  • , N. Panagia
  • , L. Testi
  • , Jorick S. Vink
  • , J. R. Walsh
  • , N. J. Wright

Research output: Contribution to journalArticlepeer-review

72 Citations (Scopus)
84 Downloads (Pure)

Abstract

As part of the Accretion Discs in H$\alpha$ with OmegaCAM (ADHOC) survey, we imaged in r, i and H-alpha a region of 12x8 square degrees around the Orion Nebula Cluster. Thanks to the high-quality photometry obtained, we discovered three well-separated pre-main sequences in the color-magnitude diagram. The populations are all concentrated towards the cluster's center. Although several explanations can be invoked to explain these sequences we are left with two competitive, but intriguing, scenarios: a population of unresolved binaries with an exotic mass ratio distribution or three populations with different ages. Independent high-resolution spectroscopy supports the presence of discrete episodes of star formation, each separated by about a million years. The stars from the two putative youngest populations rotate faster than the older ones, in agreement with the evolution of stellar rotation observed in pre-main sequence stars younger than 4 Myr in several star forming regions. Whatever the final explanation, our results prompt for a revised look at the formation mode and early evolution of stars in clusters.
Original languageEnglish
Article numberA22
Number of pages8
JournalAstronomy & Astrophysics
Volume604
Issue numberA&A
Early online date27 Jul 2017
DOIs
Publication statusE-pub ahead of print - 27 Jul 2017

Keywords

  • astro-ph.SR
  • astro-ph.GA

Fingerprint

Dive into the research topics of 'A Tale of Three Cities: OmegaCAM discovers multiple sequences in the color-magnitude diagram of the Orion Nebula Cluster'. Together they form a unique fingerprint.

Cite this