Hanny s Voorwerp
10.02.2011

Hanny's Voorwerp, Dutch for "Hanny's Object", is enormous, about the size of our own Milky Way Galaxy. Glowing strongly in the greenish light produced by ionized oxygen atoms, the mysterious voorwerp is below spiral galaxy IC 2497 in this view from the Hubble Space Telescope.

The Holographic Principle and a Teapot
3.10.2021

Sure, you can see the 2D rectangle of colors, but can you see deeper? Counting color patches in the featured image, you might estimate that the most information that this 2D digital image can hold is about 60 (horizontal) x 50(vertical) x 256 (possible colors) = 768,000 bits.

Animation: Odd Radio Circles
30.03.2022

What do you call a cosmic puzzle that no one expected to see? In this case, Odd Radio Circles, aka ORCs. ORC-1 typifies the enigmatic five objects, only visible at radio frequencies, that were serendipitously discovered in 2019 using the new Australian SKA Pathfinder radio array.

M83: The Southern Pinwheel
16.01.2025

Beautiful and bright spiral galaxy M83 lies a some twelve million light-years away, near the southeastern tip of the very long constellation Hydra. Prominent spiral arms traced by dark dust lanes and blue star clusters lend this galaxy its popular name, The Southern Pinwheel.

APOD: 2025 April 14 Б The Galactic Center in Radio from MeerKAT
14.04.2025

What's happening at the center of our galaxy? It's hard to tell with optical telescopes since visible light is blocked by intervening interstellar dust. In other bands of light, though, such as radio, the galactic center can be imaged and shows itself to be quite an interesting and active place.

Gamma Ray Earth
31.03.2005

The pixelated planet above is actually our own planet Earth seen in gamma rays - the most energetic form of light. In fact, the gamma rays used to construct this view pack over 35 million electron volts (MeV) compared to a mere two electron volts (eV) for a typical visible light photon.

Short Gamma Ray Bursts Localized
17.10.2005

What causes gamma-ray bursts? The most energetic type of explosions known in the cosmos has been an enigma since discovered over 30 years ago. It now appears that there may not be one unique type of progenitor.

A Hotspot Map of Neutron Star J0030s Surface
18.12.2019

What do neutron stars look like? Previously these city-sized stars were too small and too far away to resolve. Recently, however, the first maps of the locations and sizes of hotspots on a neutron...

Cosmic Collision Forges Galactic Ring
17.09.2018

How could a galaxy become shaped like a ring? The rim of the blue galaxy pictured on the right is an immense ring-like structure 150,000 light years in diameter composed of newly formed, extremely bright, massive stars.

375: Candidate Quark Star
14.04.2002

Why is RJX J185635-375 so cool and so dim? Previously, this compact star held claim to being the closest neutron star -- only 150 light-years away. Now new observations and analysis indicate not only a cool temperature for RXJ J185635-375, pictured above, but also a larger distance: roughly 450 light-years away.