Simeis 147: Supernova Remnant
30.08.2002

It's easy to get lost following the intricate filaments in this stunningly detailed image of faint supernova remnant Simeis 147. Seen towards the constellation Taurus it covers nearly 3 degrees (6 full moons)...

Gamma-Ray Burster
19.03.1997

What and where are the Gamma-Ray Bursters? Since their discovery in the early 1970s, nobody has been able to explain the cause of mysterious flashes of gamma rays that come from seemingly random directions on the sky.

Centaurus A: X-Rays from an Active Galaxy
5.07.2003

Its core hidden from optical view by a thick lane of dust, the giant elliptical galaxy Centaurus A was among the first objects observed by the orbiting Chandra X-ray Observatory. Astronomers were not disappointed, as Centaurus A's appearance in x-rays makes its classification as an active galaxy easy to appreciate.

Galaxy Cluster Lenses Farthest Known Galaxy
17.02.2004

Gravity can bend light, allowing whole clusters of galaxies to act as huge telescopes. Almost all of the bright objects in this just-released Hubble Space Telescope image are galaxies in the cluster known as Abell 2218.

Microquasar in Motion
16.09.2004

Microquasars, bizarre binary star systems, generating high-energy radiation and blasting out jets of particles at nearly the speed of light, live in our Milky Way galaxy. The energetic microquasar systems seem to consist...

Messier 106
29.05.2009

Close to the Great Bear (Ursa Major) and surrounded by the stars of the Hunting Dogs (Canes Venatici), this celestial wonder was discovered in 1781 by the metric French astronomer Pierre Mechain. Later, it was added to the catalog of his friend and colleague Charles Messier as M106.

Thackerays Globules
12.06.2012

These are larger dust bunnies than you will find under your bed. Situated in rich star fields and glowing hydrogen gas, these opaque clouds of interstellar dust and gas are so large they might be able to form stars.

The Comet, the Owl, and the Galaxy
24.03.2017

Comet 41P/Tuttle-Giacobini-Kresak poses for a Messier moment in this telescopic snapshot from March 21. In fact it shares the 1 degree wide field-of-view with two well-known entries in the 18th century comet-hunting astronomer's famous catalog.

APOD: 2026 March 27 Б Hickson 44 in Leo
27.03.2026

Scanning the skies for galaxies, Canadian astronomer Paul Hickson and colleagues identified some 100 compact groups of galaxies, now appropriately called Hickson Compact Groups. The four prominent galaxies seen in this intriguing telescopic skyscape are one such group, Hickson 44.

Gamma Ray Bursts from the Unknown
27.08.1995

Gamma Ray Bursts (GRBs) pose one of the greatest mysteries of modern astronomy. About once a day, the gamma-ray sky lights up with a spectacular explosion. No one knows what causes these explosions or even how far away they are.