Curious about machine learning? Learn about the inner workings of machine-learning algorithms without writing a line of code.
Contributing Editor Ted Forte offers a look at Hickson Compact Groups in the November 2017 issue of Sky & Telescope. In 1982, Canadian astronomer Paul Hickson published a list of 100 compact galaxy groups based on his examination of the Palomar Observatory Sky Survey (POSS) red plates. A compact group, as defined by Hickson, is…
Sky & Telescope Contributing Editor Ken Hewitt gives us a guided tour through Abell 194, a visually rich galaxy cluster in Cetus.
Sky & Telescope's Observing Editor offers a few suggestions to help you set up your first (for fifth!) observing notebook. Feeling inspired after reading Contributing Editor Bob King’s article on observing notebooks in the September 2017 issue of Sky & Telescope but need help starting a notebook? Here are a few different ways to approach…
No matter what you call it, Messier 17 is one deep-sky object to which you'll find yourself returning throughout your observing life. In our September 2017 issue, Contributing Editor Howard Banich examined the science and history of Messier 17, an H II region in Sagittarius also known as the Swan Nebula, Omega Nebula, Checkmark Nebula,…
Contributing Editor Matt Wedel offers more double and multiple stars to look for in and around the head of the constellation Draco, the Dragon.
If you're looking for an observing challenge, George Abell's complete catalog of planetary nebulae has you covered. I observed my first planetary nebula by accident. I was moving the optical tube of my new telescope up and down, back and forth, nearing epic levels of frustration as I hunted for anything that didn't look like…
Why would an amateur astronomer build a standing-stone calendar, thousands of years after the last ones were erected by his distant ancestors in the British Isles?
Stellar streams are the remains of dwarf galaxies that once orbited the Milky Way. We showcase here stunning images of these galactic ghosts.
In our March 2017 issue we included a diagram of all small, confirmed exoplanets in their stars’ habitable zones. Here’s the saga of how we decided which planets to put on that list.
Peruse a gallery of ultra-faint galaxies, the subject of Keith Bechtol's feature article in the April 2017 issue of Sky & Telescope. Wide-field surveys are accelerating discoveries of these elusive companions to the Milky Way.
If you see something questionable in a recent issue of Sky & Telescope magazine, check here to see a list of clarifications and errors that have been found.
Looking for a new deep-sky challenge? Turn your scope toward ACO 426, the Perseus Galaxy Cluster.
Sky & Telescope has put together a digest of active missions in 2017. We’ve included astrophysics, planetary, gravity, solar, space weather, and stellar projects.
New research on Eta Carinae featured in S&T's October 2016 issue lets you peer in and around Eta Carinae's Homunculus Nebula.
Here's an update on an amateur astronomer's amazing effort to prove that Einstein really was right during next year's total solar eclipse.
Looking for an observing challenge? An expert observer offers advice for exploring the Minkowski catalog of planetary nebulae.
To aid your observing endeavor, Contributing Editor Steve Gottlieb has provided an expanded table of galaxies, with their position angles, visual magnitudes, size, and positions.
Here is Jim Mullaney's much longer sample of objects from this delightful 1927 amateur-astronomy guide, in order of right ascension, followed by more illustrations of the book.
Watch a million stars age in these prize-winning simulations of globular clusters. The simulations track the stars' movements and evolution over 12 billion years.
Here's some further reading on the stages of star formation visible in the Trifid Nebula, subject of the May 2016 issue's Going Deep column.
How many details can you see when you take a look at galaxies M81 and M82? On October 13, 2015, Contributing Editor Howard Banich experienced a spectacular morning of observing at Steens Mountain in southeastern Oregon. With fantastic transparency and increasingly good seeing, he was able to view M82 as he'd never seen it before.…
To expand on the feature article on adaptive optics in our May 2016 issue, we're including here a full gallery of before-and-after images. The effect of the technology is immediately visible - and astounding.
Ancient cosmic sound waves (aka baryon acoustic oscillations) shaped the universe we see today. These animations demonstrate how the universe's large-scale structure came to be.
Check here for a list of known errata in 2016 issues of Sky & Telescope. If you don't see the error you found, send us an e-mail and alert us.