FYI, new article in Nature The Laniakea supercluster of galaxies - R. Brent Tully <http://www.nature.com/nature/journal/v513/n7516/full/nature13674.html?WT.ec_id=NATURE-20140904#auth-1> , - Hélène Courtois <http://www.nature.com/nature/journal/v513/n7516/full/nature13674.html?WT.ec_id=NATURE-20140904#auth-2> , - Yehuda Hoffman <http://www.nature.com/nature/journal/v513/n7516/full/nature13674.html?WT.ec_id=NATURE-20140904#auth-3> - & Daniel Pomarède <http://www.nature.com/nature/journal/v513/n7516/full/nature13674.html?WT.ec_id=NATURE-20140904#auth-4> - Affiliations <http://www.nature.com/nature/journal/v513/n7516/full/nature13674.html?WT.ec_id=NATURE-20140904#affil-auth> - Contributions <http://www.nature.com/nature/journal/v513/n7516/full/nature13674.html?WT.ec_id=NATURE-20140904#contrib-auth> - Corresponding author <http://www.nature.com/nature/journal/v513/n7516/full/nature13674.html?WT.ec_id=NATURE-20140904#corres-auth> Nature 513, 71–73 (04 September 2014) doi:10.1038/nature13674Received 07 April 2014 Accepted 07 July 2014 Published online 03 September 2014 Article tools - Citation <http://www.nature.com/nature/journal/v513/n7516/ris/nature13674.ris> - Reprints <https://s100.copyright.com/AppDispatchServlet?publisherName=NPGR&publication=Nature&title=The+Laniakea+supercluster+of+galaxies&contentID=10.1038%2Fnature13674&volumeNum=513&issueNum=7516&numPages=3&pageNumbers=pp71-73&orderBeanReset=true&publicationDate=2014-09-03&author=R.+Brent+Tully%2C+H%26%23x000E9%3Bl%26%23x000E8%3Bne+Courtois%2C+Yehuda+Hoffman%2C+Daniel+Pomar%26%23x000E8%3Bde> - Rights & permissions <https://s100.copyright.com/AppDispatchServlet?publisherName=NPG&publication=Nature&title=The+Laniakea+supercluster+of+galaxies&contentID=10.1038%2Fnature13674&volumeNum=513&issueNum=7516&numPages=3&pageNumbers=pp71-73&publicationDate=2014-09-03&author=R.+Brent+Tully%2C+H%26%23x000E9%3Bl%26%23x000E8%3Bne+Courtois%2C+Yehuda+Hoffman%2C+Daniel+Pomar%26%23x000E8%3Bde> - Article metrics <http://www.nature.com/nature/journal/v513/n7516/nature13674/metrics> Galaxies congregate in clusters and along filaments, and are missing from large regions referred to as voids. These structures are seen in maps derived from spectroscopic surveys1 <http://www.nature.com/nature/journal/v513/n7516/full/nature13674.html#ref1> , 2 <http://www.nature.com/nature/journal/v513/n7516/full/nature13674.html#ref2> that reveal networks of structure that are interconnected with no clear boundaries. Extended regions with a high concentration of galaxies are called ‘superclusters’, although this term is not precise. There is, however, another way to analyse the structure. If the distance to each galaxy from Earth is directly measured, then the peculiar velocity can be derived from the subtraction of the mean cosmic expansion, the product of distance times the Hubble constant, from observed velocity. The peculiar velocity is the line-of-sight departure from the cosmic expansion and arises from gravitational perturbations; a map of peculiar velocities can be translated into a map of the distribution of matter3 <http://www.nature.com/nature/journal/v513/n7516/full/nature13674.html#ref3>. Here we report a map of structure made using a catalogue of peculiar velocities. We find locations where peculiar velocity flows diverge, as water does at watershed divides, and we trace the surface of divergent points that surrounds us. Within the volume enclosed by this surface, the motions of galaxies are inward after removal of the mean cosmic expansion and long range flows. We define a supercluster to be the volume within such a surface, and so we are defining the extent of our home supercluster, which we call Laniakea. -- ******** Beverley Getzen Retired, US Army Corps of Engineers PO Box 202 Wadesboro, NC 28170-0202 704-694-7022 *www.carolinaswritersconference.org <http://www.carolinaswritersconference.org/>* "There are times when we are powerless to prevent injustice, but there must never be a time we fail to protest." Elie Wiesel, Holocaust survivor and Nobel Laureate.