Gamma Ray Burst, Supernova Bump
17.05.2002

On the 21st of November 2001, satellites detected yet another burst of gamma-rays from the cosmos. While this flash of high-energy photons lasted for less than a minute, eager astronomers have been following the fading optical light from the location of the burst source ever since.

Namibian Nights
4.02.2013

Namibia has some of the darkest nights visible from any continent. It is therefore home to some of the more spectacular skyscapes, a few of which have been captured in the above time-lapse video.

APOD: 2024 October 20 Б Dark Matter in a Simulated Universe
20.10.2024

Is our universe haunted? It might look that way on this dark matter map. The gravity of unseen dark matter is the leading explanation for why galaxies rotate so fast, why galaxies orbit clusters...

The Matter of the Bullet Cluster
15.01.2017

What's the matter with the Bullet Cluster? This massive cluster of galaxies (1E 0657-558) creates gravitational lens distortions of background galaxies in a way that has been interpreted as strong evidence for the leading theory: that dark matter exists within.

First Horizon Scale Image of a Black Hole
11.04.2019

What does a black hole look like? To find out, radio telescopes from around the Earth coordinated observations of black holes with the largest known event horizons on the sky. Alone, black holes are just black, but these monster attractors are known to be surrounded by glowing gas.

The Tarantula Nebula
16.11.2017

The Tarantula Nebula is more than a thousand light-years in diameter, a giant star forming region within nearby satellite galaxy the Large Magellanic Cloud, about 180 thousand light-years away. The largest, most violent star...

Rumors of a Dark Universe
4.08.2019

Twenty-one years ago results were first presented indicating that most of the energy in our universe is not in stars or galaxies but is tied to space itself. In the language of cosmologists, a large cosmological constant -- dark energy -- was directly implied by new distant supernova observations.

APOD: 2025 June 3 Б Rainbow Airglow over the Azores
3.06.2025

Why would the sky glow like a giant repeating rainbow? Airglow. Now, air glows all of the time, but it is usually hard to see. A disturbance however -- like an approaching storm -- may cause noticeable rippling in the Earth's atmosphere.

Echoes from RS Pup
12.02.2008

This dusty reflection nebula surrounds pulsating star RS Pup, some 10 times more massive than the Sun and on average 15,000 times more luminous. In fact, RS Pup is a Cepheid type variable...

Great Observatories Explore Galactic Center
11.11.2009

Where can a telescope take you? Four hundred years ago, a telescope took Galileo to the Moon to discover craters, to Saturn to discover rings, to Jupiter to discover moons, to Venus to discover phases, and to the Sun to discover spots.