Planck 2013 results. XXVII. Doppler boosting of the CMB: Eppur si muove

Planck Collaboration,, N. Aghanim, C. Armitage-Caplan, M. Arnaud, M. Ashdown, F. Atrio-Barandela, J. Aumont, A. J. Banday, R. B. Barreiro, J. G. Bartlett, K. Benabed, A. Benoit-Lévy, J. -P. Bernard, M. Bersanelli, P. Bielewicz, J. Bobin, Jacob Bock, J. R. Bond, J. Borrill, F. R. BouchetM. Bridges, C. Burigana, Robb Butler, J. F. Cardoso, A. Catalano, A. Challinor, A. Chamballu, Lung-Yih Chiang, H. C. Chiang, P. R. Christensen, D. L. Clements, L. P. L. Colombo, F. Couchot, B. P. Crill, F. Cuttaia, L. Danese, R. D. Davies, Rebecca Davis, P. de Bernardis, A. de Rosa, G. de Zotti, J. Delabrouille, J. M. Diego, S. Donzelli, O. Doré, X. Dupac, G. Efstathiou, T. A. Enßlin, H. K. Eriksen, F. Finelli, O. Forni, M. Frailis, E. Franceschi, S. Galeotta, K. Ganga, M. Giard, G. Giardino, J. González-Nuevo, K. M. Górski, S. Gratton, A. Gregorio, A. Gruppuso, F. K. Hansen, D. Hanson, D. Harrison, G. Helou, Steen Hildebrandt, E. Hivon, M. Hobson, W. A. Holmes, W. Hovest, K. M. Huffenberger, W. C. Jones, M. Juvela, E. Keihänen, R. Keskitalo, T. S. Kisner, J. Knoche, L. Knox, M. Kunz, H. Kurki-Suonio, A. Lähteenmäki, J. -M. Lamarre, A. Lasenby, C. R. Lawrence, R. Leonardi, A. Lewis, M. Liguori, P. B. Lilje, Michael Linden-Vørnle, M. López-Caniego, P. M. Lubin, J. F. Macías-Pérez, M. Maris, D. J. Marshall, P. G. Martin, E. Martínez-González, S. Masi, S. Matarrese, P. Mazzotta, P. R. Meinhold, A. Melchiorri, L. Mendes, M. Migliaccio, S. Mitra, A. Moneti, L. Montier, G. Morgante, D. Mortlock, A. Moss, D. Munshi, P. Naselsky, F. Nati, P. Natoli, Hans Ulrik Nørgaard-Nielsen, F. Noviello, D. Novikov, Igor Dmitrievich Novikov, S. Osborne, Carol Anne Oxborrow, L. Pagano, F. Pajot, D. Paoletti, F. Pasian, G. Patanchon, O. Perdereau, F. Perrotta, F. Piacentini, E. Pierpaoli, D. Pietrobon, S. Plaszczynski, E. Pointecouteau, G. Polenta, N. Ponthieu, L. Popa, G. W. Pratt, G. Prézeau, J. -L. Puget, J. P. Rachen, W. T. Reach, M. Reinecke, S. Ricciardi, T. Riller, I. Ristorcelli, G. Rocha, C. Rosset, J. A. Rubiño-Martín, B. Rusholme, D. Santos, G. Savini, D. Scott, M. D. Seiffert, E. P. S. Shellard, L. D. Spencer, R. Sunyaev, F. Sureau, A. -S. Suur-Uski, J. -F. Sygnet, J. A. Tauber, D. Tavagnacco, L. Terenzi, L. Toffolatti, M. Tomasi, M. Tristram, M. Tucci, M. Türler, L. Valenziano, J. Valiviita, B. Van Tent, P. Vielva, Frank Villa, N. Vittorio, L. A. Wade, B. D. Wandelt, M. White, D. Yvon, A. Zacchei, J. P. Zibin, A. Zonca

Research output: Contribution to journalJournal articleResearchpeer-review

355 Downloads (Pure)


Our velocity relative to the rest frame of the cosmic microwave background (CMB) generates a dipole temperature anisotropy on the sky whichhas been well measured for more than 30 years, and has an accepted amplitude of v/c = 1.23 x 10-3, or v = 369 km-1. In addition to thissignal generated by Doppler boosting of the CMB monopole, our motion also modulates and aberrates the CMB temperature fluctuations (as wellas every other source of radiation at cosmological distances). This is an order 10-3 effect applied to fluctuations which are already one part inroughly 105, so it is quite small. Nevertheless, it becomes detectable with the all-sky coverage, high angular resolution, and low noise levels of thePlanck satellite. Here we report a first measurement of this velocity signature using the aberration and modulation eects on the CMB temperatureanisotropies, finding a component in the known dipole direction, (l; b) = (264° 48°), of 384 km s-1 ± 78 km s-1 (stat.) ± 115 km s-1 (syst). This is a significant confirmation of the expected velocity.
Original languageEnglish
Article numberA27
JournalAstronomy & Astrophysics
Number of pages11
Publication statusPublished - 2013


  • Cosmology: observations
  • Cosmic background radiation
  • Reference systems
  • Relativistic processes

Cite this