A Sunspot Up Close
5.10.1998

Sometimes, small regions of the Sun appear unusually dark. Visible above is a close-up picture of a sunspot, a depression on the Sun's face that is slightly cooler and less luminous than the rest of the Sun.

Traces of the Sun
21.12.2016

This year the December Solstice is today, December 21, at 10:44 UT, the first day of winter in the north and summer in the south. To celebrate, watch this amazing timelapse video tracing the Sun's apparent movement over an entire year from Hungary.

Active Prominences on a Quiet Sun
20.08.2018

Why is the Sun so quiet? As the Sun enters into a period of time known as a Solar Minimum, it is, as expected, showing fewer sunspots and active regions than usual. The quietness is somewhat unsettling, though, as so far this year, most days show no sunspots at all.

Venus and the Triply Ultraviolet Sun
4.02.2018

An unusual type of solar eclipse occurred in 2012. Usually it is the Earth's Moon that eclipses the Sun. That year, most unusually, the planet Venus took a turn. Like a solar eclipse by the Moon, the phase of Venus became a continually thinner crescent as Venus became increasingly better aligned with the Sun.

A Solar Filament Erupts
16.09.2018

What's happened to our Sun? Nothing very unusual -- it just threw a filament. Toward the middle of 2012, a long standing solar filament suddenly erupted into space producing an energetic Coronal Mass Ejection (CME).

APOD: 2023 March 28 Б A Multiple Green Flash Sunset
28.03.2023

Yes, but can your green flash do this? A green flash at sunset is a rare event that many Sun watchers pride themselvesбon having seen.б Once thought to be a myth, a green flash is now understood to occur when the Earth's atmosphere acts like both a prism and a lens.

APOD: 2026 August 6 Б New Sharpest Image of the Sun Uncovers Instability
6.08.2026

What does the new sharpest image of our Sun show? Instability. To be clear, a certain kind of interactive process called the Kelvin-Helmholtz instability (KHI). This instability can create waves and swirls when two streams flow past each other -- in this case variable streams of solar magnetic plasma.

Aphelion Sunrise
5.07.2017

On July 3rd, planet Earth reached aphelion, the farthest point in its elliptical orbit around the Sun. Each year, this day of the most distant Sun happens to occur during winter in the southern hemisphere.

An Active Prominence on the Sun
18.06.2018

Sometimes the Sun's surface becomes a whirlwind of activity. Pictured is a time-lapse video of the Sun's surface taken over a two hour period in early May, run both forwards and backwards. The Sun's surface was blocked out so that details over the edge could be imaged in greater detail.

Black Sun and Inverted Starfield
19.02.2017

Does this strange dark ball look somehow familiar? If so, that might be because it is our Sun. In the featured image from 2012, a detailed solar view was captured originally in a very specific color of red light, then rendered in black and white, and then color inverted.