• Gould, Andrew ;
  • Huber, Daniel ;
  • Penny, Matthew ;
  • Stello, Dennis
  • Received : 2014.10.28
  • Accepted : 2014.12.30
  • Published : 2015.04.30


WFIRST microlensing observations will return high-precision parallaxes, σ(π) . 0.3 µas, for the roughly 1 million stars with H < 14 in its 2.8 deg2 field toward the Galactic bulge. Combined with its 40,000 epochs of high precision photometry (∼ 0.7 mmag at Hvega = 14 and ∼ 0.1 mmag at H = 8), this will yield a wealth of asteroseismic data of giant stars, primarily in the Galactic bulge but includindvvvvvg a substantial fraction of disk stars at all Galactocentric radii interior to the Sun. For brighter stars, the astrometric data will yield an external check on the radii derived from the two asteroseismic parameters, the large-frequency separation <∆νnl> and the frequency of maximum oscillation power νmax, while for the fainter ones, it will enable a mass measurement from the single measurable asteroseismic parameter νmax. Simulations based on Kepler data indicate that WFIRST will be capable of detecting oscillations in stars from slightly less luminous than the red clump to the tip of the red giant branch, yielding roughly 1 million detections.


astrometry;gravitational microlensing;stars: oscillations


  1. Boyajian, T. S., van Belle, G., & von Braun, K. 2014, Stellar Diameters and Temperatures. IV. Predicting Stellar Angular Diameters, AJ, 147, 47
  2. Belkacem, K., Goupil, M. J., Dupret, M. A., et al. 2011, The Underlying Physical Meaning of the vmax–vc Relation, A&A, 530, A142
  3. Bensby, T., Yee, J. C., Feltzing, S., et al. 2013, Chemical Evolution of the Galactic Bulge as Traced by Microlensed Dwarf and Subgiant Stars. V. Evidence for a Wide Age Distribution and a Complex MDF, A&A, 549, A147
  4. Bessell, M. S., & Brett, J. M. 1988, JHKLM Photometry - Standard Systems, Passbands, and Intrinsic Colors, PASP, 100, 1134
  5. Brown, T. M., Gilliland, R. L., Noyes, R. W., & Ramsey, L. W. 1991, Detection of Possible P-Mode Oscillations on Procyon, ApJ, 368, 599
  6. Casagrande, L., & VandenBerg, D. A. 2014, Synthetic Stellar Photometry - I. General Considerations and New Transformations for Broad-Band Systems, MNRAS, 444, 392
  7. Casagrande, L., Silva, A. V., Stello, D., et al. 2014, Strmgren Survey for Asteroseismology and Galactic Archaeology: Let the SAGA Begin, ApJ, 787, 110
  8. Chaplin, W. J., & Miglio, A. 2013, Asteroseismology of Solar-Type and Red-Giant Stars, ARA&A, 51, 353
  9. Epstein, C. R., Elsworth, Y. P., Johnson, J. A., et al. 2014, Testing the Asteroseismic Mass Scale Using Metal-Poor Stars Characterized with APOGEE and Kepler, ApJ, 785, L28
  10. Frandsen, S., Lehmann, H., Hekker, S., et al. 2013, KIC 8410637: a 408-Day Period Eclipsing Binary Containing a Pulsating Giant Star, A&A, 556, A138
  11. Gould, A. 2014b, A New Method to Calibrate the Stellar Color/Surface-Brightness Relation, JKAS, 47, 153
  12. Girardi, L., Barbieri, M., Groenewegen, M. A. T., et al. 2012, TRILEGAL, a TRIdimensional modeL of thE GALaxy: Status and Future, in Red Giants as Probes of the Structure and Evolution of the Milky Way (Berlin: Springer-Verlag), 165
  13. Gould, A. 1995, Analytic Error Estimates, ApJ, 440, 510
  14. Gould, A. 2014a, WFIRST Ultra-Precise Astrometry I: Kuiper Belt Objects, JKAS, 47, 279
  15. Gould, A., Udalski, A., Shin, J.-G., et al. 2014, A Terrestrial Planet in a - AU Orbit Around One Member of a - 15 AU Binary, Science, 345, 46
  16. Hekker, S., Elsworth, Y., De Ridder, J., et al. 2011, Solar-Like Oscillations in Red Giants Observed with Kepler: Comparison of Global Oscillation Parameters from Different Methods, A&A, 525, A131
  17. Huber, D., Stello, D., Bedding, T. R., et al. 2009, Automated Extraction of Oscillation Parameters for Kepler Observations of Solar-Type Stars, Communications in Asteroseismology, 160, 74
  18. Huber, D., Bedding, T. R., Stello, D., et al. 2011, Testing Scaling Relations for Solar-Like Oscillations from the Main Sequence to Red Giants Using Kepler Data, ApJ, 743, 143
  19. Huber, D., Ireland, M. J., Bedding, T. R., et al. 2012, Fundamental Properties of Stars Using Asteroseismology from Kepler and CoRoT and Interferometry from the CHARA Array, ApJ, 760, 32
  20. Kallinger, T., Weiss, W. W., Barban, C., et al. 2010, Oscillating Red Giants in the CoRoT Exofield: Asteroseismic Mass and Radius Determination, A&A, 509, A77
  21. Kervella, P., Thévenin, F., Di Folco, E., & Ségransan, D. 2004, The Angular Sizes of Dwarf Stars and Subgiants. Surface Brightness Relations Calibrated by Interferometry, A&A, 426, 297
  22. Nataf, D. M., Gould, A., Fouqué, P., et al. 2013, Reddening and Extinction toward the Galactic Bulge from OGLE-III: The Inner Milky Way's RV - 2.5 Extinction Curve, ApJ, 769, 88
  23. Kjeldsen, H., & Bedding, T. R. 1995, Amplitudes of Stellar Oscillations: the Implications for Asteroseismology, A&A, 293, 87
  24. Koch, D. G., Borucki, W. J., Basri, G., et al. 2010, Kepler Mission Design, Realized Photometric Performance, and Early Science, ApJ, 713, L79
  25. Miglio, A., Chiappini, C., Morel, T., et al. 2013, Differential Population Studies Using Asteroseismology: Solar-Like Oscillating Giants in CoRoT Fields LRc01 and LRa01, EPJWC, 4303004
  26. Oliva, E., Diolaiti, E., Garilli, B., et al. 2012, The Design of the MOONS-VLT Spectrometer, SPIE, 8446V
  27. Pinsonneault, M. P., Elsworth, Y., Epstein, C., et al. 2014, The APOKASC Catalog: An Asteroseismic and Spectroscopic Joint Survey of Targets in the Kepler Fields, ApJS, 215, 19
  28. Sandquist, E., Mathieu, R. D., Brogaard, K., et al. 2013, A Long-Period Totally Eclipsing Binary Star at the Turnoff of the Open Cluster NGC 6819 Discovered with Kepler, ApJ, 762, 58
  29. Stello, D., Bruntt, H., Preston, H., & Buzasi, D. 2008, Oscillating K Giants with the WIRE Satellite: Determination of Their Asteroseismic Masses, ApJ, 674, L53
  30. Stello, D., Chalin, W. J., Basu, S., Elsworth, Y., & Bedding, T. R. 2009, The Relation between ∆v and vmax for Solar-Like Oscillations, MNRAS, 400, L80
  31. Ulrich, R. K. 1986, Determination of Stellar Ages from Asteroseismology, ApJ, 306, 37
  32. Vanhollebeke, E., Groenewegen, M. A. T., & Girardi, L. 2009, Stellar Populations in the Galactic Bulge. Modelling the Galactic Bulge with TRILEGAL, A&A, 498, 95
  33. White, T. R., Bedding, T. R., Stello, D., et al. 2011, Calculating Asteroseismic Diagrams for Solar-Like Oscillations, ApJ, 743, 161
  34. White, T. R., Huber, D., Maestro, V., et al. 2013, Interferometric Radii of Bright Kepler Stars with the CHARA Array: Cygni and 16 Cygni A and B, MNRAS, 433, 1262
  35. Yoo, J., DePoy, D. L., Gal-Yam, A., et al. 2004, OGLE-2003-BLG-262: Finite-Source Effects from a Point-Mass Lens, ApJ, 603, 139

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