Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Transiting extrasolar planetary candidates in the Galactic bulge

Nature volume 443, pages 534–540 (2006)Cite this article

Abstract

More than 200 extrasolar planets have been discovered around relatively nearby stars, primarily through the Doppler line shifts owing to reflex motions of their host stars, and more recently through transits of some planets across the faces of the host stars. The detection of planets with the shortest known periods, 1.2–2.5 days, has mainly resulted from transit surveys which have generally targeted stars more massive than 0.75 M⊙, where M⊙ is the mass of the Sun. Here we report the results from a planetary transit search performed in a rich stellar field towards the Galactic bulge. We discovered 16 candidates with orbital periods between 0.4 and 4.2 days, five of which orbit stars of masses in the range 0.44–0.75 M⊙. In two cases, radial-velocity measurements support the planetary nature of the companions. Five candidates have orbital periods below 1.0 day, constituting a new class of ultra-short-period planets, which occur only around stars of less than 0.88 M⊙. This indicates that those orbiting very close to more-luminous stars might be evaporatively destroyed or that jovian planets around stars of lower mass might migrate to smaller radii.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Figure 1: CMD of the SWEEPS 202″ × 202″ field in the Galactic bulge.
Figure 2: Example transit light curves.
Figure 3: RV measurements.
Figure 4: Plot of orbital period against host-star mass.

Similar content being viewed by others

References

  1. Mayor, M. & Queloz, D. A. Jupiter-mass companion to a solar-type star. Nature 378, 355–359 (1995)

    Article  ADS  CAS  Google Scholar 

  2. Marcy, G. W. & Butler, R. P. A planetary companion to 70 Virginis. Astrophys. J. 464, L147–L151 (1996)

    Article  ADS  Google Scholar 

  3. Schneider, J. The Extrasolar Planets Encyclopaedia http://www.obspm.fr/encycl/encycl.html.

  4. Butler, R. P. et al. A Neptune-mass planet orbiting the nearby M dwarf GJ 4361. Astrophys. J. 617, 580–588 (2004)

    Article  ADS  CAS  Google Scholar 

  5. Bonfils, X. et al. The HARPS search for southern extra-solar planets VI. A Neptune-mass planet around the nearby M dwarf Gl 581. Astron. Astrophys. 443, L15–L18 (2005)

    Article  ADS  CAS  Google Scholar 

  6. Beaulieu, J.-P. et al. Discovery of a cool planet of 5.5 Earth masses through gravitational microlensing. Nature 439, 437–440 (2006)

    Article  ADS  CAS  Google Scholar 

  7. Charbonneau, D., Brown, T. M., Latham, D. W. & Mayor, M. Detection of planetary transits across a Sun-like star. Astrophys. J. 529, L45–L48 (2000)

    Article  ADS  CAS  Google Scholar 

  8. Henry, G., Marcy, G. W., Butler, R. P. & Vogt, S. S. A transiting 51 Peg-like planet. Astrophys. J. 529, L41–L44 (2000)

    Article  ADS  CAS  Google Scholar 

  9. Udalski, A. et al. The Optical Gravitational Lensing Experiment. Additional planetary and low-luminosity object transits from the OGLE 2001 and 2002 observational campaigns. Acta Astron. 53, 133–149 (2003)

    ADS  Google Scholar 

  10. Konacki, M., Torres, G., Jha, S. & Sasselov, D. An extrasolar planet that transits the disk of its parent star. Nature 421, 507–509 (2003)

    Article  ADS  CAS  Google Scholar 

  11. Bouchy, X. X. et al. Two new ‘very hot Jupiters’ among the OGLE transiting candidates. Astron. Astrophys. 421, L13–L16 (2004)

    Article  ADS  Google Scholar 

  12. Moutou, C., Pont, F., Bouchy, F. & Mayor, M. Accurate radius and mass of the transiting exoplanet OGLE-TR-132b. Astron. Astrophys. 424, L31–L34 (2004)

    Article  ADS  Google Scholar 

  13. Pont, F. et al. The ‘missing link’: A 4-day period transiting exoplanet around OGLE-TR-111. Astron. Astrophys. 426, L15–L18 (2004)

    Article  ADS  Google Scholar 

  14. Bouchy, F. et al. Doppler follow-up of OGLE transiting companions in the Galactic bulge. Astron. Astrophys. 431, 1105–1121 (2005)

    Article  ADS  Google Scholar 

  15. Alonso, R. et al. TrES-1: the transiting planet of a bright K0 V star. Astrophys. J. 613, L153–L156 (2004)

    Article  ADS  CAS  Google Scholar 

  16. Sato, B. et al. The N2K Consortium. II. A transiting hot Saturn around HD 149026 with a large dense core. Astrophys. J. 633, 465–473 (2005)

    Article  ADS  Google Scholar 

  17. Bouchy, F. et al. ELODIE metallicity-biased search for transiting hot Jupiters II. A very hot Jupiter transiting the bright K star HD189733. Astron. Astrophys. 444, l15–l19 (2005)

    Article  ADS  CAS  Google Scholar 

  18. McCullough, P. et al. A transiting planet of a Sun-like star. Astrophys. J. (in the press); preprint at http://www.arXiv.org/astro-ph/0605414 (2006)

  19. Borucki, W. J. & Summers, A. L. The photometric method of detecting other planetary systems. Icarus 58, 121–134 (1984)

    Article  ADS  Google Scholar 

  20. Zoccali, M. et al. Age and metallicity distribution of the galactic bulge from extensive optical and near-IR stellar photometry. Astron. Astrophys. 399, 931–956 (2003)

    Article  ADS  Google Scholar 

  21. Fulbright, J. P., McWilliam, A. & Rich, R. M. Abundances of Baade's Window giants from Keck/HIRES spectra: I. Stellar parameters and [Fe/H] values. Astrophys. J. 636, 821–841 (2006)

    Article  ADS  CAS  Google Scholar 

  22. Kuijken, K. & Rich, R. M. Hubble Space Telescope WFPC2 proper motions in two bulge fields: kinematics and stellar population of the Galactic bulge. Astrophys. J. 124, 2054–2066 (2002)

    ADS  Google Scholar 

  23. Zoccali, M. et al. The initial mass function of the Galactic bulge down to ∼0.15 Msolar. Astrophys. J. 530, 418–428 (2000)

    Article  ADS  Google Scholar 

  24. Brown, T. M. et al. Stellar cluster fiducial sequences with the Advanced Camera for Surveys. Astron. J. 130, 1693–1706 (2005)

    Article  ADS  CAS  Google Scholar 

  25. VandenBerg, D. A., Bergbusch, P. A. & Dowler, P. D. The Victoria-Regina stellar models: evolutionary tracks and isochrones for a wide range in mass and metallicity that allow for empirically constrained amounts of convective core overshooting. Astrophys. J. Suppl. Ser. 162, 375–387 (2006)

    Article  ADS  CAS  Google Scholar 

  26. Castelli, F. & Kurucz, R. L. in Modelling of Stellar Atmospheres (eds Piskunov, N., Weiss, W. W. & Gray, D. F.) A20 (Proc. 210th Symp. IAU, Astronomical Society of the Pacific, San Francisco, 2003)

    Google Scholar 

  27. Sumi, T. et al. The Optical Gravitational Lensing Experiment: catalogue of stellar proper motions in the OGLE-II Galactic bulge fields. Mon. Not. R. Astron. Soc. 348, 1439–1450 (2004)

    Article  ADS  Google Scholar 

  28. Rich, R. M. & Origlia, L. The first detailed abundances for M giants in Baade's Window from infrared spectroscopy. Astrophys. J. 634, 1293–1299 (2005)

    Article  ADS  CAS  Google Scholar 

  29. Kovacs, G., Zucker, S. & Mazeh, T. A box-fitting algorithm in the search for periodic transits. Astron. Astrophys. 391, 369–377 (2002)

    Article  ADS  Google Scholar 

  30. Agol, E., Farmer, A. & Mandel, K. Analytic lightcurves for planetary transit searches. Astrophys. J. 580, L171–L175 (2002)

    Article  ADS  Google Scholar 

  31. Baraffe, I., Chabrier, G., Barman, T. S., Allard, F. & Hauschildt, P. H. Evolutionary models for cool brown dwarfs and extrasolar giant planets. The case of HD 209458. Astron. Astrophys. 402, 701–712 (2003)

    Article  ADS  Google Scholar 

  32. Burrows, A., Hubeny, I., Hubbard, W. B. & Sudarsky, D. Theoretical radii of transiting giant planets: the case of OGLE-TR-56b. Astrophys. J. 610, L53–L56 (2004)

    Article  ADS  Google Scholar 

  33. Brown, T. M. Expected detection and false alarm rates for transiting Jovian planets. Astrophys. J. 593, L125–L128 (2003)

    Article  ADS  CAS  Google Scholar 

  34. Duquennoy, A. & Mayor, M. Multiplicity among solar-type stars in the solar neighbourhood. II. Distribution of the orbital elements in an unbiased sample. Astron. Astrophys. 258, 485–524 (1991)

    ADS  Google Scholar 

  35. Pont, F. et al. A planet-sized transiting star around OGLE-TR-122. Accurate mass and radius near the hydrogen-burning limit. Astron. Astrophys. 433, L21–L24 (2005)

    Article  ADS  CAS  Google Scholar 

  36. Marcy, G. Observed properties of exoplanets: masses, orbits, and metallicities. Prog. Theor. Phys. Suppl. 158, 24–42 (2005)

    Article  ADS  Google Scholar 

  37. Pont, F. et al. Doppler follow-up of OGLE planetary transit candidates in Carina. Astron. Astrophys. 438, 1123–1140 (2005)

    Article  ADS  Google Scholar 

  38. Pont, F. et al. Radius and mass of a transiting M dwarf near the hydrogen-burning limit. OGLE-TR-123. Astron. Astrophys. 447, 1035–1039 (2006)

    Article  ADS  CAS  Google Scholar 

  39. Gilliland, R. L. et al. A lack of planets in 47 Tucanae from a Hubble Space Telescope search. Astrophys. J. 545, L47–L51 (2000)

    Article  ADS  Google Scholar 

  40. Albrow, M. D. et al. The frequency of binary stars in the core of 47 Tucanae. Astrophys. J. 559, 1060–1081 (2001)

    Article  ADS  Google Scholar 

  41. Fischer, D. A. & Valenti, J. The planet-metallicity correlation. Astrophys. J. 622, 1102–1117 (2005)

    Article  ADS  CAS  Google Scholar 

  42. Valenti, J. A. & Fischer, D. A. Spectroscopic Properties of Cool Stars (SPOCS). I. 1040 F, G, and K dwarfs from Keck, Lick, and AAT Planet Search programs. Astrophys. J. Suppl. Ser. 159, 141–166 (2005)

    Article  ADS  CAS  Google Scholar 

  43. Lin, D. N. C., Bodenheimer, P. & Richardson, D. C. Orbital migration of the planetary companion of 51 Pegasi to its present location. Nature 380, 606–607 (1996)

    Article  ADS  CAS  Google Scholar 

  44. Trilling, D. et al. Orbital migration of giant planets: modeling extrasolar planets. Astrophys. J. 500, 428–439 (1998)

    Article  ADS  Google Scholar 

  45. Grauer, A. D. & Bond, H. E. The precataclysmic nucleus of Abell 41. Astrophys. J. 271, 259–263 (1983)

    Article  ADS  Google Scholar 

  46. Baraffe, I. et al. The effect of evaporation on the evolution of close-in giant planets. Astron. Astrophys. 419, L13–L16 (2004)

    Article  ADS  Google Scholar 

  47. Vardavas, I. M. The dependence of the Rossby number and XUV-Lyα emission flux with age for solar-like G-type stars. Mon. Not. R. Astron. Soc. 363, L51–L55 (2005)

    Article  ADS  Google Scholar 

  48. Lecavelier des Etangs, A., Vidal-Madjar, A., McConnell, J. C. & Hebrard, G. Atmospheric escape from hot Jupiters. Astron. Astrophys 418, L1–L4 (2004)

    Article  ADS  Google Scholar 

  49. Gilliland, R. L., Nugent, P. E. & Phillips, M. M. High-redshift supernovae in the Hubble Deep Field. Astrophys. J. 521, 30–49 (1999)

    Article  ADS  Google Scholar 

  50. Stetson, P. B. in Astronomical Data Analysis Software and Systems I (eds Worrall, D. M., Biemesderfer, C. & Barnes, J.) 297–306 (ASP Conf. Series Vol. 25, Astronomical Society of the Pacific, San Francisco, 1992)

Download references

Acknowledgements

This article is based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the AURA, Inc. under a NASA contract, and with the Very Large Telescope at the ESO, Paranal, Chile. We thank R. Gilliland for his generous contribution of time and efforts for this project, and D. Bradstreet, I. Jordan, G. Kovacs, D. VandenBerg and the late A. Lubenow for their help at various stages of the project.

Author information

Authors and Affiliations

  1. Space Telescope Science Institute, 3700 San Martin Drive, Maryland, 21218, Baltimore, USA

    Kailash C. Sahu, Stefano Casertano, Howard E. Bond, Jeff Valenti, T. Ed Smith, Mario Livio, Nino Panagia, Thomas M. Brown, Will Clarkson & Stephen Lubow

  2. Universidad Catolica de Chile, Av. Vicuña Mackenna 4860, 22, Santiago, Chile

    Dante Minniti & Manuela Zoccali

  3. Uppsala University, Box 515, S-751 20, Uppsala, Sweden

    Nikolai Piskunov

  4. High Altitude Observatory, 3450 Mitchell Lane, Colorado, 80307, Boulder, USA

    Timothy Brown

  5. INAF–Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, 35122, Padova, Italy

    Alvio Renzini

  6. University of California at Los Angeles, California, 90095-1562, Los Angeles, USA

    R. Michael Rich

Authors
  1. Kailash C. Sahu
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Stefano Casertano
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Howard E. Bond
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Jeff Valenti
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. T. Ed Smith
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Dante Minniti
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Manuela Zoccali
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Mario Livio
    View author publications

    You can also search for this author in PubMed Google Scholar

  9. Nino Panagia
    View author publications

    You can also search for this author in PubMed Google Scholar

  10. Nikolai Piskunov
    View author publications

    You can also search for this author in PubMed Google Scholar

  11. Thomas M. Brown
    View author publications

    You can also search for this author in PubMed Google Scholar

  12. Timothy Brown
    View author publications

    You can also search for this author in PubMed Google Scholar

  13. Alvio Renzini
    View author publications

    You can also search for this author in PubMed Google Scholar

  14. R. Michael Rich
    View author publications

    You can also search for this author in PubMed Google Scholar

  15. Will Clarkson
    View author publications

    You can also search for this author in PubMed Google Scholar

  16. Stephen Lubow
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Kailash C. Sahu.

Ethics declarations

Competing interests

Reprints and permissions information is available at www.nature.com/reprints. The authors declare no competing financial interests.

Supplementary information

Supplementary Figures Legends

This file contains text to accompany the below Supplementary Figures. (DOC 21 kb)

Supplementary Figure 1a

Full-resolution transit light curves. (JPG 96 kb)

Supplementary Figure 1b

Full-resolution transit light curves. (JPG 90 kb)

Supplementary Figure 1c

Full-resolution transit light curves. (JPG 96 kb)

Supplementary Figure 1d

Full-resolution transit light curves. (JPG 96 kb)

Supplementary Figure 2a

Binned transit light curves. (JPG 82 kb)

Supplementary Figure 2b

Binned transit light curves. (JPG 74 kb)

Supplementary Figure 2c

Binned transit light curves. (JPG 79 kb)

Supplementary Figure 2d

Binned transit light curves. (JPG 80 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Sahu, K., Casertano, S., Bond, H. et al. Transiting extrasolar planetary candidates in the Galactic bulge. Nature 443, 534–540 (2006). https://doi.org/10.1038/nature05158

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature05158

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing