The Distance Scale of the Universe

  • Wendy L. Freedman
  • Barry F. Madore
Reference work entry


We critically review the methods currently being used to determine extragalactic distances. Within the Milky Way, direct parallaxes and traditional main-sequence fitting for both young open clusters and old globular clusters tie us directly to high-luminosity, variable stars used in extragalactic studies: Cepheids and RR Lyrae stars. These, in turn, inform a calibration of the tip of the red giant branch as well as red clump stars. Apart from the Milky Way, we focus on the Large Magellanic Cloud as an important stopping point at which a large variety of possible distance indicators have been evaluated and differentially tested against each other. Beyond the Local Group many stellar distance indicators fall below current detection and/or resolution limits, and they must be replaced with methods employing higher luminosity (and often much more rare) objects. These methods include the properties of nuclear masers, surface brightness fluctuations, the Tully–Fisher relation, and finally various types of supernovae. Ultimately a calibration of the expansion rate of the universe can provide distances using observed recessional velocities scaled by the Hubble constant.


Very Long Baseline Interferometry White Dwarf Distance Modulus Large Magellanic Cloud Distance Indicator 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. Aaronson, M., Huchra, J. P., & Mould, J. R. 1979, ApJ, 229, 1ADSGoogle Scholar
  2. Aaronson, M., Bothun, G., Mould, J., Huchra, J., Schommer, R. A., & Cornell, M. E. 1986, ApJ, 302, 536ADSGoogle Scholar
  3. Albrecht, A., Bernstein, G., Cahn, R., Freedman, W. L., Hewitt, J., et al. 2006, astro-ph/0609591Google Scholar
  4. Alcock, C., Allsman, R. A., Alves, D. R., Axelrod, T. S., et al. 2000, AJ, 119, 2194ADSGoogle Scholar
  5. Alloin, D., & Gieren, W. 2003, in Stellar Candles for the Extragalactic Distance Scale, Lecture Notes in Physics, ed. D. Alloin, & W. Gieren (Heidelberg: Springer), 635, 1Google Scholar
  6. Alves, R. D. 2000, ApJ, 539, 732ADSGoogle Scholar
  7. Alves, R. D. 2004, New AR, 48, 659ADSGoogle Scholar
  8. Alves, R. D., & Sarajedini, A. 1999, ApJ, 511, 225ADSGoogle Scholar
  9. Alves, R. D., Rejkuba, M., Minniti, D., & Cook, K. H. 2002, ApJL, 573, 51Google Scholar
  10. Arp, H. C. 1956, AJ, 61, 15ADSGoogle Scholar
  11. Baade, W. 1926, AN, 228, 359ADSGoogle Scholar
  12. Barnes, T. G. 2009, in Stellar Pulsation: Challenges for Theory and Observation, AIP Conference Proceedings, Vol. 1170, ed. J. A. Guzik, & P. A. Bradley (Melville: American Institute of Physics), 3Google Scholar
  13. Baron, E., Hauschildt, P. H., Branch, D., et al. 1995, ApJ, 441, 170ADSGoogle Scholar
  14. Baron, E., Nugent, P. E., Branch, D., & Hauschildt, P. H. 2004, ApJ, 616, L91ADSGoogle Scholar
  15. Bellazzini, M. 2008, Mem. Soc. Astron. Ital. 79, 440ADSGoogle Scholar
  16. Benedict, G. F., McArthur, B. E., Feast, M. W., Barnes, T. G. Harrison, T. E., et al. 2007, ApJ, 79, 453Google Scholar
  17. Biscardi, I., Raimondo, G., Cantiello, M., & Brocato, E. 2008, ApJ, 678, 168ADSGoogle Scholar
  18. Blakeslee, J. P., Lucey, J. R., Tonry, J. L., Hudson, M. J., Narayanan, V. K., & Barris, B. J. 2002, MNRAS, 330, 443ADSGoogle Scholar
  19. Blakeslee, J. P., Jordan, A., Mei, S., Cote, P., Ferrarese, L., et al. 2009, ApJ, 694, 556ADSGoogle Scholar
  20. Blakeslee, J. P., Cantiello, M., Mei, S., Cote, P., DeGraaff, R. B., Ferrarese, L., et al. 2010, ApJ, 724, 657ADSGoogle Scholar
  21. Bono, G. 2003, in Stellar Candles for the Extragalactic Distance Scale, Lecture Notes in Physics, Vol. 635, ed. D. Alloin, & W. Gieren (Heidelberg: Springer), 85Google Scholar
  22. Braatz, J. A., Reid, M. J., Humphreys, E. M., Henkel, C., Condon, J. J., & Lo, K. Y. 2010, ApJ, 718, 657ADSGoogle Scholar
  23. Branch, D. 1998. ARAA, 36, 17ADSGoogle Scholar
  24. Brunthaler, A., Reid, M. J., Falcke, H., Greenhill, M. J., & Henkel, C. 2005, Science, 307, 1440ADSGoogle Scholar
  25. Buchler, J. R. 2009, in Stellar Pulsation, Challenges for Theory and Observation, ed. J. Guzik, & P. Bradley. AIP Conference Proceedings, Vol. 1170, 51. astro-ph/0907.1766Google Scholar
  26. Capaccioli, M., della Valle, M., Rossino, L., & D’Onofrio, M. 1989, AJ, 97, 1622Google Scholar
  27. Capaccioli, M., della Valle, M., D’Onofrio, M., & Rosino, L. 1990, ApJ, 360, 63Google Scholar
  28. Caputo, F. 2008, Mem. Soc. Astron. Ital. 79, 453ADSGoogle Scholar
  29. Catelan, M., Pritzl, B. J., & Smith, H. A. 2004, ApJS, 154, 633ADSGoogle Scholar
  30. Ciardullo, R. 2003, in Stellar Candles for the Extragalactic Distance Scale, Lecture Notes in Physics, Vol. 635, ed. D. Alloin, & W. Gieren (Heidelberg: Springer), 243Google Scholar
  31. Ciardullo, R. 2005, in Planetary Nebulae as Astronomical Tools, AIP Conference Proceedings, Vol. 804, ed. R. Szczerba, G. Stasinska, & S. K. Gorny (Melville: American Institute of Physics), 277Google Scholar
  32. Ciardullo, R., Jacoby, G. H., Ford, H. C., & Neill, J. D. 1989, ApJ, 339, 53ADSGoogle Scholar
  33. Ciardullo, R., Feldmeier, J. J., Jacoby, G. H., Kuzio de Naray, R., Laychak, M. B., et al. 2002, ApJ, 577, 31Google Scholar
  34. Contreras, C., Hamuy, M., Phillips, M. M., Folatelli, G., Suntzeff, N. B., et al. 2010, AJ, 139, 519ADSGoogle Scholar
  35. Cox, J. P. 1980, Theory of Stellar Pulsation Princeton: Princeton University PressGoogle Scholar
  36. Da Costa, G. S., & Armandroff, T. E. 1990, AJ, 100, 162ADSGoogle Scholar
  37. Darling, J. 2011, ApJL, 732, 2Google Scholar
  38. de Grijs, R. 2011, An Introduction to Distance Measurement in Astronomy (Chichester: Wiley)Google Scholar
  39. de Jong, J. T. A., Rix, H., Martin, N. F., Zucker, D. B., Dolphin, A. E., Bell, E. F., Belokurov, V., & Evans, N. W. 2008, AJ, 135, 1361ADSGoogle Scholar
  40. Della Valle, M., & Livio, M. 1995, ApJ, 452, 704ADSGoogle Scholar
  41. Dessart, L., & Hiller, D. J. 2005, A&A, 439, 671ADSGoogle Scholar
  42. di Benedetto, G. P. 2008, MNRAS, 390, 1762ADSGoogle Scholar
  43. Dolphin, A. E. 2002, MNRAS, 332, 91ADSGoogle Scholar
  44. Eastman, R. G., & Kirshner, R. P. 1989, ApJ, 347, 771ADSGoogle Scholar
  45. Eastman, R. G., Schmidt, B. P., & Kirshner, R. 1996, ApJ, 466, 911ADSGoogle Scholar
  46. Feast, M. W., & Catchpole, R. M. 1997, MNRAS, 286, L1ADSGoogle Scholar
  47. Fernie, J. D. 1969, PASP, 81, 707ADSGoogle Scholar
  48. Ferrarese, L., et al. 2000, ApJ, 529, 745ADSGoogle Scholar
  49. Ferrarese, L., Cote, P., & Jordan, A. 2003, ApJ, 612, 1261Google Scholar
  50. Folatelli, G., Phillips, M. M., Burns, C. R., Contreras, C., Hamuy, M., et al. 2010, AJ, 139, 120ADSGoogle Scholar
  51. Forbes, D. A., Brodie, J. P., & Grillmair, C. J. 1997, AJ, 113, 1652ADSGoogle Scholar
  52. Fouque, P., Arriagada, P., Storm, J., Barnes, T. G., Nardetto, N., et al. 2007, A&A, 476, 73ADSGoogle Scholar
  53. Freedman, W. L., & Madore, B. F. 2010, ARAA, 48, 673ADSGoogle Scholar
  54. Freedman, W. L., Madore, B. F., Monson, A, Persson, S. E., Scowcroft, V., Seibert, M., & Rigby, J. 2012, ApJ, 758, 24Google Scholar
  55. Freedman, W. L., Madore, B. F., Gibson, B. K., Ferrarese, L., Kelson, D. D., et al. 2001, ApJ, 553, 47ADSGoogle Scholar
  56. Freedman, W. L., Madore, B. F., Rigby, J., Persson, S. E., & Sturch, L. 2008, ApJ, 679, 71ADSGoogle Scholar
  57. Gascoigne, S. C. B., & Shobbrook, R. R. 1978, PASA, 3, 285ADSGoogle Scholar
  58. Gilmozzi, R., & Della Valle, M. 2003, in Stellar Candles for the Extragalactic Distance Scale, Lecture Notes in Physics, Vol. 635, ed. D. Alloin, & W. Gieren (Heidelberg: Springer), 229Google Scholar
  59. Giovanelli, R., Haynes, M. P., Herter, T., Vogt, N. P., da Costa, L. N., et al. 1997, AJ, 113, 53ADSGoogle Scholar
  60. Girardi, L., & Salaris, M. 2001, MNRAS, 323, 109ADSGoogle Scholar
  61. Gnedin, O. Y. & Ostriker, J. P. 1998, in Galactic Halos, ASP Conference Series, Vol. 136, ed. D. Zaritsky, 56Google Scholar
  62. Grocholski, A. J., & Sarajedini, A. 2002, AJ, 123, 1603ADSGoogle Scholar
  63. Hamuy, M., Phillips, M. M., Suntzeff, N. B., Schommer, R. A., Maza, J., et al., 1996, AJ,112, 2398Google Scholar
  64. Hanes, D. A. 1977, MNRAS, 180, 309ADSGoogle Scholar
  65. Hanes, D. A. 1979, A new determination of the Hubble Constant, MNRAS, 188, 901ADSGoogle Scholar
  66. Heck, A., & Caputo, F. 1999, Post-Hipparcos Cosmic Candles, A&SSL (Dordrecht: Kluwer)Google Scholar
  67. Henkel, C., Wouterloot, J. G. A., & Bally, J. 1986, A&A, 155, 193ADSGoogle Scholar
  68. Herrnstein, J. R., Moran, J. M., Greenhill, L. J., Diamond, P. J., Inoue, M., et al. 1999, Nature, 400, 539ADSGoogle Scholar
  69. Hicken, M., Wood-Vasey, W. M., Blondin, S., Challis, P., Jha, S., et al. 2009, ApJ, 700, 1097ADSGoogle Scholar
  70. Hillebrandt, W., & Niemeyer, J. C. 2000, ARAA, 38, 191ADSGoogle Scholar
  71. Hodge, P. 1982, ARAA, 19, 357ADSGoogle Scholar
  72. Hubble, E. E. 1925, ApJ, 62, 409ADSGoogle Scholar
  73. Hubble, E. P. 1926, ApJ, 63, 236ADSGoogle Scholar
  74. Hubble, E. P. 1929, ApJ, 69, 103ADSGoogle Scholar
  75. Huchra, J. P. 1992, Science, 256, 321ADSGoogle Scholar
  76. Humphreys, E. M. L., Reid, M. J., Greenhill, L. J., Moran, J. M. & Argon, A. L. 2008, ApJ, 672, 800ADSGoogle Scholar
  77. Iben, I., & Renzini, A. 1983, ARAA, 21, 271ADSGoogle Scholar
  78. Jackson, N. 2007 Living Rev. Relativ. 10, 4ADSGoogle Scholar
  79. Jacoby, G. H., Branch, D., Ciardullo, R., Davies, R. L., Harris, W. E., et al. 1992, PASP, 104, 599ADSGoogle Scholar
  80. Jacoby, G. H., & Ciardullo, R. 1993, in Planetary Nebulae, Proceedings IAU Symposium, Vol. 155, ed. R. Weinberger, & A. Acker (Dordrecht/Boston: Kluwer), 503Google Scholar
  81. Jameson, R. F. 1986, Vistas Astron., 29, 17ADSGoogle Scholar
  82. Jha, S., Kirshner, R. P., Challis, P., Garnavich, P. M., Matheson, T., et al. 2006, AJ, 131, 527ADSGoogle Scholar
  83. Jones, W. C., Ade, P. A. R., Bock, J. J., Bond, J. R., Borrill, L., et al. 2006, ApJ, 647, 823ADSGoogle Scholar
  84. Kirshner, R. P., & Kwan, J. 1974, ApJ, 193, 27ADSGoogle Scholar
  85. Koerwer, J. F. 2009, AJ, 138, 1ADSGoogle Scholar
  86. Komatsu, E., Dunkley, J., Nolta, M. R., Bennett, C. L., Gold, B., et al. 2009, ApJS, 180, 330ADSGoogle Scholar
  87. Kowal, C. T. 1968, AJ, 73, 1021ADSGoogle Scholar
  88. Leavitt, H. S. 1908, Ann. Harv. Coll. Obs., 60, 87ADSGoogle Scholar
  89. Leavitt, H. S., & Pickering, E. C. 1912, Harv. Coll. Obs. Circ., 173, 1ADSGoogle Scholar
  90. Lee, M. G., Freedman, W. L., & Madore, B. F. 1993, ApJ, 417, 553ADSGoogle Scholar
  91. Livio, M., Donahue, M., & Panagia, N. 1999, The Extragalactic Distance Scale, STScI Symposium, No. 10 (Cambridge: Cambridge University Press)Google Scholar
  92. Lo, K. Y. 2005, ARAA, 43, 625ADSGoogle Scholar
  93. Loeb, A., Reid, M. J., & Falke, H. 2005, ApJ, 633, 894ADSGoogle Scholar
  94. Longmore, A. J., Fernley, J. A., & Jameson, R. F. 1986, MNRAS, 220, 279ADSGoogle Scholar
  95. Macri, L. M., Stanek, K. Z., Bersier, D., Greenhill, L. J., & Reid, M. J. 2006, ApJ, 652, 1133ADSGoogle Scholar
  96. Madore, B. F., & Freedman, W. L. 1991, PASP, 103, 933ADSGoogle Scholar
  97. Madore, B. F., & Freedman, W. L. 2012, ApJ, 744, 132ADSGoogle Scholar
  98. Madore, B. F., Mager, V., & Freedman, W. F. 2009, ApJ, 690, 389ADSGoogle Scholar
  99. Mager, V., Madore, B. F., & Freedman, W. F. 2008, ApJ, 689, 721ADSGoogle Scholar
  100. Maoz, E., Newman, J. A., Ferrarese, L., Stetson, P. B., Zepf, S. E., et al. 1999, Nature, 401, 351ADSGoogle Scholar
  101. McGaugh, S. S., Schombert, J. M., Bothun, G. D., & de Blok, W. J. G. 2000, ApJL, 533, L99ADSGoogle Scholar
  102. Monson, A., Freedman, W. L., Madore, B. F., et al. 2012, ApJGoogle Scholar
  103. Mould, J., & Sakai, S. 2008, ApJL, 686, L75ADSGoogle Scholar
  104. Mould, J., & Sakai, S. 2009a, ApJ, 694, 1331ADSGoogle Scholar
  105. Mould, J., & Sakai, S. 2009b, ApJ, 697, 996ADSGoogle Scholar
  106. Mould, J. R., Huchra, J. P., Freedman, W. L., Kennicutt, R. C., Ferrarese, L., et al. 2000, ApJ, 529, 786ADSGoogle Scholar
  107. Newman, J. A., Ferrarese, L., Stetson, P. B., Maoz, E., Zepf, S. E., et al. 2001, ApJ, 553, 562ADSGoogle Scholar
  108. Nolta, M., Dunkley, J., Hill, R. S., Hinshaw, G., Komatsu, E., et al. 2009, ApJS, 180, 296ADSGoogle Scholar
  109. Paczynski, B., & Stanek, K. Z. 1998, ApJL, 494, 219Google Scholar
  110. Perryman, M. A. C. 2009, Astronomical Applications of Astromentry: Ten Years of Exploitation of the Hipparcos Satellite Data (Cambridge: Cambridge University Press)Google Scholar
  111. Phillips, M. M. 1993, ApJL, 413, L105ADSGoogle Scholar
  112. Pierce, M. J., & Tully, R. B. 1988, ApJ, 330, 579ADSGoogle Scholar
  113. Pietrzynski, G., Gieren, W., & Udalski, A. 2003, AJ, 125, 2494ADSGoogle Scholar
  114. Pietrzynski, G., Gorski, M., Gieren, W., Laney, D., Udalski, A., & Ciechanowski, A. 2010, AJ, 140, 1038ADSGoogle Scholar
  115. Pskovskii, Y. P. 1984, Sov. AJ, 28, 658ADSGoogle Scholar
  116. Readhead, A. C. S., Mason, B. S., Contaldi, C. R., Pearson, T. J., Bond, J. R., et al. 2004, ApJ, 609, 498ADSGoogle Scholar
  117. Reichardt, C., Ade, P. A. R., Bock, J. J., Bond, J. R., Brevik, J. A., et al. 2009, ApJ, 694, 1200ADSGoogle Scholar
  118. Reid, M. J., Braatz, J. A., Condon, J. J., Greenhill, L. J., Henkel, C., et al. 2009, ApJ, 695, 287ADSGoogle Scholar
  119. Richler, T. 2003, in Stellar Candles for the Extragalactic Distance Scale, Lecture Notes in Physics, Vol. 635, ed. D. Alloin, & W. Gieren (Heidelberg: Springer), 281Google Scholar
  120. Riess, A. G., Macri, L., Casertano, S., Sosey, M., Lampeitl, H., et al. 2009a, ApJ, 699, 539ADSGoogle Scholar
  121. Riess, A. G., Macri, L., Li, W., Lampeitl, H., Casertano, S., et al. 2009b, ApJS, 183, 109ADSGoogle Scholar
  122. Riess, A. G., Macri, L., Casertano, S., Lampeitl, H., Ferguson, H. C., Filippenko, A. V., Jha, S. W., Li, W., & Chornock, R. 2011, ApJ, 730, 119ADSGoogle Scholar
  123. Rizzi, L., Tully, R. B., Makarov, D., Makarova, L., Dolphin, A. E., et al. 2007, ApJ, 661, 81ADSGoogle Scholar
  124. Rowan-Robinson, M. 1985, The Cosmological Distance Ladder, Distance and Time in the Universe (New York: W. H. Freeman)Google Scholar
  125. Saha, A., Sandage, A. R., Tammann, G. A., Labhardt, L., Macchetto, F. D., et al. 1999, ApJ, 522, 802ADSGoogle Scholar
  126. Sakai, S., Mould, J. R., Hughes, S. M. G., Huchra, J. P., Macri, L. M., et al. 2000, ApJ, 529, 698ADSGoogle Scholar
  127. Sandage, A. R. 1968, ApJL, 152, 149Google Scholar
  128. Sandage, A. R., Saha, A., Tammann, G. A., Labhardt, L., Panagia, N.,& Macchetto, F. D. 1996, ApJL, 460, 15Google Scholar
  129. Sandage, A. R., & Tammann, G. A. 1982, ApJ, 265, 339ADSGoogle Scholar
  130. Sandage, A. R., & Tammann, G. A. 1990, ApJ, 365, 1ADSGoogle Scholar
  131. Sandage, A. R., & Tammann, G. A. 2006, ARRA, 44, 93Google Scholar
  132. Sarajedini, A., 1999, AJ, 118, 2321ADSGoogle Scholar
  133. Sarajedini, A., Grocholski, A. J., Levine, J., & Lada, E. 2002, AJ, 124, 2625ADSGoogle Scholar
  134. Scowcroft, V., Freedman, W. L., Madore, B. F., Monson, A. J., Persson, S. E., Seibert, M., Rigby, J. R., & Sturch, L. 2011, ApJ, 743, 76ADSGoogle Scholar
  135. Scowcroft, V., Freedman, W. L., Madore, B. F., Monson, A., Persson, E., Seibert, M., Rigby, J., Stetson, P., & Sturch, L. 2012, ApJ, 747, 84ADSGoogle Scholar
  136. Schaeffer, B. 2008, AJ, 135, 112ADSGoogle Scholar
  137. Seibert, M., Freedman, W. L., Madore, B. F., Monson, A., Persson, E., Scowcroft, V. M., Rigby, J., Stetson, P., & Sturch, L. 2012, ApJGoogle Scholar
  138. Seidel, E., Da Costa, G. S., & Demarque, P. 1987 ApJ, 313, 192ADSGoogle Scholar
  139. Smith, R. 1982, The Expanding Universe, Astronomy’s Great Debate 1900–1931 (Cambridge: Cambridge University PressGoogle Scholar
  140. Smith, H. A. 1995, RR Lyrae Stars, Cambridge Astrophysics Series, Vol. 27 (Cambridge/New York: Cambridge University Press)Google Scholar
  141. Soszynski, I., Poleski, R., Udalski, A., Szymanski, M. K., Kubiak, M., et al. 2008, Acta. Astron. 58, 163ADSGoogle Scholar
  142. Stanek, K. Z., Zaritsky, D. & Harris, J. 1998, ApJ, 500, L141ADSGoogle Scholar
  143. Steinmetz, M., & Navarro, J. 1999, ApJ, 513, 555ADSGoogle Scholar
  144. Tammann, G. A., & Sandage, A. 1999, in Harmonizing Cosmic Distance Scales in a Post-Hipparcos Era, ASP Conference Series, Vol. 167, ed. D. Egret, & A. Heck (San Francisco : Astronomical Society of the Pacific), 204Google Scholar
  145. Tammann, G. A., Sandage, A. R., & Reindl, B. 2008, A&AR, 15, 289ADSGoogle Scholar
  146. Tolstoy, E., & Saha, A. 1996, ApJ, 462, 672ADSGoogle Scholar
  147. Tonry, J., & Schneider, D. P. 1988, AJ, 96, 807ADSGoogle Scholar
  148. Tonry, T. J., Dressler, A., Blakeslee, J. P., Ajhar, E. A., Fletcher, A. B., Luppino, G. A., Metzger, M. R., & Moore, C. B. 2001, ApJ, 546, 681ADSGoogle Scholar
  149. Tonry, T. J., Blakeslee, J. P., Ajhar, E. A., & Dressler, A. 2002, ApJ, 530, 625ADSGoogle Scholar
  150. Tully, R. B., & Fisher, J. R. 1977, A&A, 54, 661ADSGoogle Scholar
  151. Tully, R. B., & Pierce, M. J. 2000, ApJ, 553, 744ADSGoogle Scholar
  152. Udalski, A., 2000, Acta Astron., 50, 279ADSGoogle Scholar
  153. Udalski, A., Szymanski, M., Kubiak, M., et al. 1998, Acta Astron., 48, 147ADSGoogle Scholar
  154. van den Bergh, S. 1992, PASP, 104, 861ADSGoogle Scholar
  155. van den Bergh, S., & Pritchet, C. (eds.) 1988, The Extragalactic Distance Scale, ASP Conference Series, Vol. 4. (San Francisco: Astronomical Society of the Pacific)Google Scholar
  156. Webb, S. 1999, Measuring the Universe (Praxis: Springer)Google Scholar
  157. Weinberg, M. D., & Nikolaev, S. 2001, ApJ, 548, 712ADSGoogle Scholar
  158. Whelan, J., & Iben, I. J. 1973, ApJ, 186, 100ADSGoogle Scholar
  159. Wilcots, E. M., & Miller, B. W. 1998, AJ, 116, 2363ADSGoogle Scholar
  160. Wood-Vasey, W. M., Friedman, A. S., Bloom, J. S., Hicken, M., Modjaz, M., et al. 2008, ApJ, 689, 377ADSGoogle Scholar
  161. Zwicky, F. 1336, PASP, 48, 191Google Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  • Wendy L. Freedman
    • 1
  • Barry F. Madore
    • 2
  1. 1.Carnegie ObservatoriesPasadenaUSA
  2. 2.Carnegie ObservatoriesPasadenaUSA

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