N2K Consortium

Searching the Next 2000 Stars for Hot Jupiters

Artwork by Lynette Cook

N2K Project Overview
Ongoing precise radial velocity surveys of ~2000 stars have discovered over 200 extrasolar planets, including many "Hot Jupiters": massive planets orbiting surprisingly close to their host stars. Fortuitous alignment of the orbital planes has caused such planets to transit in front of bright host stars, revealing a wealth of information about these planets: density, composition, and even interior structure.

The N2K Consortium is a multinational, distributed observing program searching the "Next 2000" stars not already being surveyed. Its goal is to discover dozens of new hot jupiters, and learn more about their internal and atmospheric properties.

Method
 Using the now well-established correlation between host stars' heavy element abundance and the frequency of planets, we select high metallicity stars from a pool of 14,000, and distribute them to three observatories: Keck, Subaru and Magellan. Precise radial velocities obtained over three nights at these observatories identify candidate hot jupiters for intense monitoring. Planets then found in small orbits (P < 14 days) have relatively high probability for transit (~10%) and are monitored photometrically at Fairborn Observatory. A full description of our technique can be found in the first paper below.

Results
 Publications from the N2K consortium:

  1. The N2K Consortium. I. A Hot Saturn Planet Orbiting HD 88133 Fischer, D., et al ApJ 620, 481, 2004.
  2. The N2K Consortium. II. A Transiting Hot Saturn Around HD 149026 with a Large Dense Core Sato, et al 2005. Accepted by ApJ.   See the HD 149026 web page.
  3. "The N2K Consortium. III. Short-Period Planets Orbiting HD 149143 and HD 109749" Fischer, D. et al., 2006, ApJ 637, 1094
  4. "The N2K Consortium. IV. New Temperatures and Metallicities for More than 100,000 FGK Dwarfs" 2006, Ammons, S.M., Robinson, S. E., Strader, J., Laughlin, G., Fischer, D., Wolf, A., ApJ, 638, 1004
  5. The N2K Consortium. V. Identifying Very Metal-rich Stars with Low- Resolution Spectra: Finding Planet-Search Targets 2006, Robinson, S. E., Strader, J., Ammons, S. M., Laughlin, G., Fischer, D. A. ApJ 637, 1102
  6. "The N2K Consortium VI: Doppler Shifts Without Templates and Three New Short-Period Planets." 2006. Johnson, J., A., Marcy, G. W., Fischer, D. A., Laughlin, G., Butler, R. P., Henry, G. W., Valenti, J. A., Ford, E. B., Vogt, S. S., Wright, J. T. ApJ, 647
  7. The N2K Consortium. VII. Atmospheric Parameters of 1907 Metal-rich Stars: Finding Planet-Search Targets 2007 Robinson, Sarah E.; Ammons, S. Mark; Kretke, Katherine A.; Strader, Jay; Wertheimer, Jeremy G.; Fischer, Debra A.; Laughlin, Gregory. ApJS 169, 430
  8. Five Intermediate-Period Planets from the N2K Sample, 2007. D. Fischer, et al. Accepted by ApJ
  9. The N2K Consortium VIII. Catalog of Keck Velocities and Stellar Parameters for 435 Stars. 2007. Fischer, D. A., Johnson, J. A., Valenti, J., Wright, J. T., Marcy, G. W., Butler, R. P., Laughlin, G., McCarthy, C., Vogt, S. S., Henry, G. W.,In prep ApJS
News
October 2008: HD 17156 b, a planet we recently discovered, has now been shown to transit!
June, 2005: New transiting planet: HD 149026 .

Team Members
Debra Fischer1 & Greg Laughlin2 Principal Investigators
G. Henry8, G. Marcy3, P. Butler4, S. Vogt2, C. McCarthy1, J. Valenti9 Co-Investigators (USA)
T. Johnson, R. Sareen, K.L. Tah, D. Abouav Students (SFSU)
M. Ammons, S. Robinson, J. Strader, A. Wolf Students (UCSC)
J. Johnson, J. Wright Students (UCB)
Bun'ei Sato5, Shigeru Ida6 Co-Investigators (Japan)
Dante Minniti7 Co-Investigator (Chile)

Institutions

  1. San Francisco State University (SFSU)
  2. U.C. Santa Cruz (UCSC)
  3. U.C. Berkeley
  4. Carnegie Institute of Washington, Dept. of Terrestrial Magnetism
  5. Kobe University
  6. Tokyo Institute of Technology
  7. Pontificia Universidad Catolica
  8. Tennessee State University
  9. Space Telescope Science Institute (STScI)
To review a DEMONSTRATION SAMPLE data release from this project, please Click Here
Acknowledgements We wish to thank our Research Sponsors:

NASA Origins Program: Exploring the Universe
Cottrell Award Program Research Corporation

San Francisco State University
 Dept. of Physics & Astronomy, College of Science & Engineering
Webpage Design: C. McCarthy, D. Abouav