Sky and Telescope - January 2018 - 4
SPECTRUM
by Peter Tyson
Rippled Fabric of Astronomy
The Essential Guide to Astronomy
Founded in 1941 by Charles A. Federer, Jr.
and Helen Spence Federer
ALL LAST SUMMER few of us in the office could talk of anything
except the spectacular event of August 21st. But in early fall the
eclipse got eclipsed. For something to unseat the Great American
Totality, it had to be a whopper, and it was (see page 10).
The fifth direct observation of the ripples in spacetime known as
gravitational waves, announced on October 16th, shook up the field we report
on like a bear whacking a beehive. A sizeable portion of the world's astronomers
dropped everything to study its aftermath, and altogether, this single event in
the galaxy NGC 4993 triggered a staggering amount of groundbreaking science:
*It's the first time astronomers have observed a cosmic event in both gravitational waves and light - in a sense, they both heard and saw it.
*It ushers in an entirely new era of "multi-messenger astronomy." Traditional
astronomy has previously had only electromagnetic radiation to work with; now
it has another "messenger" - gravitational waves.
*It provides further confirmation of general relativity, which predicts that
gravitational waves should travel at the speed of light.
*It's the first time astronomers witnessed the merging of two neutron stars
(the collapsed, incomprehensibly dense cores of high-mass stars).
*It validates the theory that such neutron-star mergers produce many elements heavier than iron, including gold, lead, and platinum, and spew them
violently out into space, where they end up in places like Earth.
*It represents the first confirmed observation of a kilonova, which lies in luminosity somewhere between a nova and a supernova.
*It confirms the hypothesis that at least some short gamma-ray bursts - terrifically energetic blasts of radiation - originate in neutron-star mergers.
Not bad for an event that took place 130 million years ago in a far-off galaxy.
For more on these and other results, watch our next issue for a comprehensive
feature by Contributing Editor Govert Schilling, author of Ripples in Spacetime:
Einstein, Gravitational Waves, and the Future of Astronomy, published in 2017.
As for what this event has meant to astronomers, few said it better than Edo
Berger of the Harvard-Smithsonian Center for Astrophysics: "It's hard to describe
our sense of excitement and historical purpose over the past couple of months.
This is a once-in-a-career moment - we have fulfilled a dream of scientists that
has existed for decades."
The Royal Swedish Academy of Sciences might well agree, having awarded the
2017 Nobel Prize in Physics to three researchers deeply involved in the design of,
and theorizing behind, the instruments that made all this possible.
Totality? What totality?
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JA N UA RY 2 018 * SK Y & TELESCOPE
EDITORIAL
Editor in Chief Peter Tyson
Senior Editors J. Kelly Beatty, Alan M. MacRobert
Equipment Editor Sean Walker
Science Editor Camille M. Carlisle
News Editor Monica Young
Associate Editor S. N. Johnson-Roehr
Observing Editor Diana Hannikainen
Project Coordinator Bud Sadler
Digital Content Strategist Janine Myszka
Senior Contributing Editors
Robert Naeye, Roger W. Sinnott
Contributing Editors
Howard Banich, Jim Bell, Trudy Bell,
John E. Bortle, Greg Bryant, Thomas A. Dobbins,
Alan Dyer, Tom Field, Tony Flanders, Ted Forte,
Sue French, Steve Gottlieb, David Grinspoon,
Ken Hewitt-White, Johnny Horne, Bob King,
Emily Lakdawalla, Jerry Lodriguss, Rod Mollise,
James Mullaney, Donald W. Olson, Jerry Oltion,
Joe Rao, Dean Regas, Fred Schaaf,
Govert Schilling, William Sheehan, Mike Simmons,
Mathew Wedel, Alan Whitman, Charles A. Wood,
Robert Zimmerman
Contributing Photographers
P. K. Chen, Akira Fujii, Robert Gendler,
Babak Tafreshi
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Sky and Telescope - January 2018
Table of Contents for the Digital Edition of Sky and Telescope - January 2018
Contents
Sky and Telescope - January 2018 - Cover1
Sky and Telescope - January 2018 - Cover2
Sky and Telescope - January 2018 - 1
Sky and Telescope - January 2018 - Contents
Sky and Telescope - January 2018 - 3
Sky and Telescope - January 2018 - 4
Sky and Telescope - January 2018 - 5
Sky and Telescope - January 2018 - 6
Sky and Telescope - January 2018 - 7
Sky and Telescope - January 2018 - 8
Sky and Telescope - January 2018 - 9
Sky and Telescope - January 2018 - 10
Sky and Telescope - January 2018 - 11
Sky and Telescope - January 2018 - 12
Sky and Telescope - January 2018 - 13
Sky and Telescope - January 2018 - 14
Sky and Telescope - January 2018 - 15
Sky and Telescope - January 2018 - 16
Sky and Telescope - January 2018 - 17
Sky and Telescope - January 2018 - 18
Sky and Telescope - January 2018 - 19
Sky and Telescope - January 2018 - 20
Sky and Telescope - January 2018 - 21
Sky and Telescope - January 2018 - 22
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Sky and Telescope - January 2018 - 24
Sky and Telescope - January 2018 - 25
Sky and Telescope - January 2018 - 26
Sky and Telescope - January 2018 - 27
Sky and Telescope - January 2018 - 28
Sky and Telescope - January 2018 - 29
Sky and Telescope - January 2018 - 30
Sky and Telescope - January 2018 - 31
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Sky and Telescope - January 2018 - 33
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Sky and Telescope - January 2018 - 55
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Sky and Telescope - January 2018 - 84
Sky and Telescope - January 2018 - Cover3
Sky and Telescope - January 2018 - Cover4
Sky and Telescope - January 2018 - SGA18SAL
Sky and Telescope - January 2018 - 90
Sky and Telescope - January 2018 - SGA18S
Sky and Telescope - January 2018 - SGA18SA
Sky and Telescope - January 2018 - SGA18EAL
Sky and Telescope - January 2018 - 94
Sky and Telescope - January 2018 - SGA18E
Sky and Telescope - January 2018 - SGA18EA
Sky and Telescope - January 2018 - SGA18RAL
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Sky and Telescope - January 2018 - SGA18R
Sky and Telescope - January 2018 - SGA18RA
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