HCG 87: A Small Group of Galaxies
6.07.2010

Sometimes galaxies form groups. For example, our own Milky Way Galaxy is part of the Local Group of Galaxies. Small, compact groups, like Hickson Compact Group 87 (HCG 87) shown above, are interesting partly because they slowly self-destruct.

Illustration: An Early Quasar
22.02.2022

What did the first quasars look like? The nearest quasars are now known to involve supermassive black holes in the centers of active galaxies. Gas and dust that falls toward a quasar glows brightly, sometimes outglowing the entire home galaxy.

X-Ray Wind From NGC 3783
1.06.2000

A black hole is supposed to inexorably attract matter. But the intense radiation generated as material swirls and plunges into its high gravity field also heats up surrounding gas and drives it away.

Messier 77
10.05.2013

Face-on spiral galaxy M77 lies a mere 47 million light-years away toward the aquatic constellation Cetus. At that estimated distance, the gorgeous island universe is about 100 thousand light-years across. Also known...

The Outskirts of M77
7.12.2006

Face-on spiral galaxy M77 lies a mere 60 million light-years away toward the constellation Cetus. Also known as NGC 1068, it's very bright core is well studied by astronomers exploring the mysteries of supermassive black holes in active galaxies.

NGC 5643: Nearby Spiral Galaxy from Hubble
5.10.2020

What's happening at the center of spiral galaxy NGC 5643? A swirling disk of stars and gas, NGC 5643's appearance is dominated by blue spiral arms and brown dust, as shown in the featured image taken by the Hubble Space Telescope.

The X-ray Timing Explorer
3.01.1996

Launched Saturday on a Delta rocket, the X-ray Timing Explorer (XTE) will watch the sky for rapid changes in X-rays. XTE carries three separate X-ray telescopes. The Proportional Counter Array (PCA) and the High Energy X-ray Timing Experiment (HEXTE) will provide the best timing information in the widest X-ray energy range yet available.

Gamma ray Rain from 3C 279
22.07.2015

If gamma-rays were raindrops a flare from a supermassive black hole might look like this. Not so gently falling on the Fermi Gamma-ray Space Telescope from June 14 to June 16 the gamma-ray photons, with energies up to 50 billion electron volts, originated in active galaxy 3C 279 some 5 billion light-years away.

Simulated Gamma ray Sky
31.05.2006

Scheduled for launch in 2007, the Gamma-ray Large Area Space Telescope (GLAST) will explore the Universe in gamma-rays, the most energetic form of light. To get ready, consider this dynamic gamma-ray sky animation - constructed from simulating the first 55 days (seen above at one frame per day) of GLAST observations of cosmic gamma-ray sources.

Galaxy NGC 4388 Expels Huge Gas Cloud
3.06.2002

Why are huge clouds of gas billowing from spiral galaxy NGC 4388? The extent of the gas clouds, over 100,000 light-years, was unexpected before the Subaru Telescope took the above image. NGC 4388 has a bright energetic nucleus and so is classified as an active galaxy.