How to Reveal the X-ray Universe, Make a Habitable Planet, and Catch Star-Blown Bubbles

As the Chandra and XMM-Newton X-ray observatories observe two decades in space this year, S&T News Editor Monica Young celebrates the field of X-ray astronomy in our cover story. Since astronomers learned to rise above our atmosphere with the coming of the Space Age, X-rays have opened a new window on the universe. Meanwhile, satellites have played just as large a role in discovering worlds around stars near and far. But how many of these — especially those around volatile but common M dwarfs — are habitable? While August's Perseid meteor shower will compete with a 95%-lit Moon, the shower is long-lived, so head out as early as late July to see it. Meanwhile, the sky holds plenty other treasures, from deep-sky wonders that you can behold even through small telescopes to planets in morning and evening skies, and even three asteroids that are nearing opposition and visible through binoculars. For those with bigger scopes, here's a challenge: spot supernovae before they happen in Wolf-Rayet stars, massive stars already shedding their outer layers. In this issue, you'll also find guides to the evening and morning skies, explorations of lunar craters, and an S&T Test Report on Nikon's mirrorless Z6 camera.

Feature Articles

A star goes poof!
Cassiopeia A supernova remnant, seen in X-rays

Pioneers of the Invisible Universe
Researchers seeking the X-ray sky revealed a hot, lively, and revolutionary cosmos.
By Monica Young

Small-Scope Summer
Embrace the constraints of a small instrument for deep-sky observing this season.
By Brian Ventrudo

Catch a Wind-blown Bubble
Mysterious in origin and ethereal in nature, Wolf-Rayet nebulae intrigue both observer and reader alike.
By Steve Gottlieb

Red Dwarf Habitability Recipe
Life on worlds around the smallest stars would cope with environments vastly different from our own.
By Igor Palubski & Aomawa Shields

Governing the Planets
This year marks the 400th anniversary of Kepler’s Third Law of Motion.
By F. Michael Witkoski

Smartphone Nightscaping
The ever-improving quality of cameras in smart devices makes nightscape astrophotography a snap.
By Jeff Dai


Beyond the Printed Page

Simulation of neutron star - black hole merger
Simulation of a neutron star - black hole merger.
F. Foucart (U. of New Hampshire) / SXS Collaboration / Classical and Quantum Gravity, 34, 4 (2017)

New LIGO Results: The Full Story
Find out how amateurs can participate in LIGO research.

Two Decades of X-rays
Relive two decades on the frontier of discovery
with Chandra and XMM-Newton.

View the Ice Giants
Find Uranus and Neptune in the summer sky.


Anthony Wesley

Two Large, One Small
The two gas giants continue to enthrall us during the earlier part of the night, while plucky Mercury delights us in the morning.
By Fred Schaaf

Three for One
Three asteroids, traveling conveniently close to one another in the southern sky, come to opposition this month.
By S. N. Johnson-Roehr

Unruly Crater Rays
These long, bright streaks crisscross the lunar surface yet defy easy explanation.
By Charles Wood

The Glorious Eagle
Many lesser-known clusters and nebulae swarm around the mighty Eagle Nebula.
By Sue French

Table of Contents
See what else August's issue has to offer.


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July 9, 2019 at 1:06 am

I subscribe to sky and telescope, and I have not got my August issue this is the second time this happened, I am very unhappy that I'm not receiving my issues when I already paid for a yrs subscription. I also cannot download the digital copy from your website, please send me my August issue asap thank you shawn

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Monica Young

July 9, 2019 at 7:17 am

We have forwarded your request to customer service. In the future, you can email them directly at this email address: [email protected]

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Nicole Sharp

August 30, 2019 at 12:06 pm

I never received an August 2019 print issue either.

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Monica Young

September 3, 2019 at 9:40 am

Dear Nicole, I'm afraid our customer service team doesn't monitor these comments. If you have any problems with your subscription, you can contact our customer service team at [email protected]. Thanks!

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