M13: The Great Globular Cluster in Hercules
14.11.2007

M13 is modestly recognized as the Great Globular Cluster in Hercules. A system of stars numbering in the hundreds of thousands, it is one of the brightest globular star clusters in the northern sky.

Omega Centauri: The Brightest Globular Cluster
1.05.2013

This huge ball of stars predates our Sun. Long before humankind evolved, before dinosaurs roamed, and even before our Earth existed, ancient globs of stars condensed and orbited a young Milky Way Galaxy. Of the 200 or so globular clusters that survive today, Omega Centauri is the largest, containing over ten million stars.

Orion Nebula in Oxygen, Hydrogen, and Sulfur
4.06.2013

Few astronomical sights excite the imagination like the nearby stellar nursery known as the Orion Nebula. The Nebula's glowing gas surrounds hot young stars at the edge of an immense interstellar molecular cloud.

Massive Black Hole Shreds Passing Star
27.10.2015

What happens when a star gets too close to a black hole? Recent observations from Earth-orbiting observatories of an event dubbed ASASSN-14li, in a distant galactic center, appears to be giving one star's harrowing story.

The Light, the Dark, and the Dusty
4.03.2020

This colorful skyscape spans about four full moons across nebula rich starfields along the plane of our Milky Way Galaxy in the royal northern constellation Cepheus. Near the edge of the region's massive...

APOD: 2023 November 6 Б Red Aurora over Italy
5.11.2023

What was that red glow on the horizon last night? Aurora. Our unusually active Sun produced a surface explosion a few days ago that sent out a burst of electrons, protons, and more massive charged nuclei.

Sculpting the South Pillar
2.06.2005

Eta Carinae, one of the most massive and unstable stars in the Milky Way Galaxy, has a profound affect on its environment. Found in the the South Pillar region of the Carina Nebula, these...

Zodiacal Light Over Laguna Verde
28.10.2009

An unusual triangle of light is visible this time of year just before dawn, in the northern hemisphere. Once considered a false dawn, this triangle of light is actually Zodiacal Light, light reflected from interplanetary dust particles.

Baryon Acoustic Oscillations from SDSS III
20.01.2014

How large do things appear when far away? When peering across the universe, the answer can actually tell us about its average gravitational history and hence its composition. Toward this goal, the Baryon Oscillation...

Shell Game in the LMC
28.12.2016

An alluring sight in southern skies, the Large Magellanic Cloud (LMC) is seen here through narrowband filters. The filters are designed to transmit only light emitted by ionized sulfur, hydrogen, and oxygen atoms. Ionized...