Smoky sun

Explore the Night with Bob King

Eking Out Observing from under Wildfire Smoke

Smoke from Canadian wildfires has made observing the night sky a challenge for many. Here are some ways you can make the best of a bad situation.

solar flare

Solar System

The Sun Is Waking Up — Right On Schedule

The Sun is ramping up activity, but contrary to some reports, this solar cycle is still consistent with scientists' predictions.

Halpha sun with prominences

Celestial Objects to Observe

How to Safely See a Solar Eclipse

Our star is an amazing object to observe, whether by eye or with optical aid. These time-tested tips will let you see the solar disk worry-free.

Sunspots at solar minimum vs. maximum

Solar System

The Sun’s Activity Cycle Is Stabilizing

Solar Cycle 25 is here, and forecasts suggest the next decade of the Sun’s activity will mimic the last one — halting a 40-year trend.


95 Sunrises Along the Columbia Riverbank

Margaret Greenwood explores the changing location of sunrises throughout the year.

Coronal mass ejection

Orbital Path Podcasts with Michelle Thaller

Orbital Path 10: Done in the Sun

Michelle Thaller speaks with NASA's Alex Young about the space agency's impressive fleet of Sun-monitoring spacecraft — including the upcoming Solar Probe Plus.


Celestial News & Events

Call for Solar Observers (Sept. 19–27)

Does your version of stargazing involve pointing your telescope at the Sun? With the right equipment, you can aid a project that aims to catch a solar flare in the act of erupting. The observing campaign is coming up soon: September 19 - 27, 2015.

Astronomy Questions & Answers

What is a Sundog, and How Did "Sundogs" Get Their Name?

Why are "sundogs" called by that name? Bob Johnson / Photo Gallery Before answering the why question, let me answer the what question that comes before: namely, what is a sundog, or mock Sun, in the first place? A sundog is a concentrated patch of sunlight occasionally seen about…

Sunspot AR2192

Hobby-based Q&A

How can you determine a sunsport's size compared to that of Earth?

  Turn off the telescope's motor drive (if any). Count the number of seconds it takes for the sunspot to drift past crosshairs or any speck of dust that is visible in your eyepiece. The number of seconds equals the spot's breadth in Earth diameters. The method is approximate. If…

Astronomy Questions & Answers

When is the earliest sunrise of the year?

The earliest sunrise of the year doesn't always occur on June 20th (the solstice), which has the longest day. Why? The earliest sunrise actually depends partly on latitude. In 2004, for latitude 40° north, it was June 13th. For 50° north, the earliest sunrise was on June 16th. At 30°…

Sun through hydrogen-alpha filter

Celestial Objects to Observe

Observing the Sun Safely: Sunspots, Faculae, and Flares

The surface of the Sun is a dynamic, living place that can change unpredictably from day to day.


Celestial News & Events

Watch This (Sun) Spot

Sunspots change their shape and size as they travel across the face of the Sun. Catch an evolving sunspot group caught in the act.

Celestial News & Events

Big Sunspot Group Spawns Flares, Auroras

A very active sunspot group is rotating to face Earth. Radio disruptions have already begun, and auroras may light the night skies.

Celestial News & Events

Sunspots Visible

After weeks of having a face free of large blemishes, the Sun now sports a Jupiter-sized spot, large enough to be visible without magnification if you use a safe solar filter.

Celestial News & Events

A Naked-Eye Spot Returns

The immense sunspot group that on November 4th ejected the largest solar flare ever recorded has rotated around the Sun and is back for a second pass across the Earth-facing side of the solar disk.

Celestial News & Events

Solar Flare Again Spawns an Aurora

For the second time in the last few days, a powerful flare on the Sun triggered an unusual display of the aurora borealis over some of the world's midlatitudes.

Celestial News & Events

Large Sunspot Visible

After being nearly featureless for several weeks, the solar face now sports a large sunspot.

Celestial News & Events

The Sun Remains Active

A large sunspot group has returned to the Earth-facing side of the Sun.

Celestial News & Events

Giant Sunspot Group Still Visible

A large sunspot complex will remain visible for several more days before disappearing around the Sun's limb.