NASA Astrobiology Institute (NAI)

1. NEWBORN BINARIES

   Project Investigators: Bo Reipurth, Michael Connelley, John Bally

   Other Project Members

   Marcelo Guimaraes (Doctoral Student)

   Summary

   Young binaries have orbital properties that still reflect their birth
   conditions. We have studied such binaries in two cases: deeply
   embedded newborn binaries still embedded in their nascent clouds and
   young binaries in the Orion Nebula Cluster.

   Astrobiology Roadmap Objectives:

   • Objective 1.2: Indirect and direct astronomical observations of extrasolar habitable planets

   Project Progress

   I have for 20 years pursued the study of young binaries, and during the past few years I have worked with my graduate student Michael Connelley (now postdoc at NASA/Ames) to push this study to ever younger targets. We have over the past year published several major papers on the youngest binaries ever studied, and have demonstrated that such binaries have properties that reflect their birth conditions and are different from older binaries. In another large study, we have examined the distribution of binary separations in the Orion Nebula Cluster using the Hubble Space Telescope, demonstrating that the closer to the center of the cluster, the closer are the binary components to each other, because binaries with wider separations have been disrupted by passage through the dense cluster center. This is a result predicted by numerical models, and now for the first time demonstrated empirically.

   Cross-Team Collaborations

   John Bally is member of the Colorado NAI

Publications

Bally, J., Reipurth, B. & Davis, C.J.  (2007).  Observations of Jets and Outflows from Young Stars.  In: B. Reipurth, D. Jewitt & K. Keil (Eds.).  Review for Protostars and Planets V (pp. 215-230).

Connelley, M.S., Reipurth, B. & Tokunaga, A.T.  (2008).  The evolution of the multiplicity of embedded protostars. I. Sample properties and binary detections.  Astronomical Journal, 135(6):2496-2525  [Online].

Connelley, M.S., Reipurth, B. & Tokunaga, A.T.  (2008).  The evolution of the multiplicity of embedded protostars. II. Binary separation distribution and analysis.  Astronomical Journal, 135(6):2526-2536  [Online].

Reipurth, B., Guimaraes, M.M., Connelley, M.S. & Bally, J.  (2007).  Visual binaries in the Orion Nebula Cluster.  Astronomical Journal, 134(6):2272-2285  [Online].

Walawender, J., Reipurth, B. & Bally, J.  ().  Multiple Outflows and Protostars in Barnard 1. II Deep Optical and Near Infrared Images.  Astronomical Journal, In press.

Whitworth, A., Bate, M.R., Nordlund, A., Reipurth, B. & Zinnecker, H.  (2007).  The Formation of Brown Dwarfs: Theory.  In: B. Reipurth, D. Jewitt & K. Keil (Eds.).  Review for Protostars and Planets (pp. 459-476).