QSO H1821 643 Indicates a Universe Filled with Hydrogen
16.05.2000

A quasar slightly depleted of a specific color of light may indicate that our universe is filled with massive amounts of ionized hydrogen. Light from QSO H1821+643, pictured above, comes to us from about a quarter of the way across the visible universe.

USNO A2.0 Catalog: A Digital Sky
26.04.1999

Here lie 526,230,881 of the brightest stars known. The US Naval Observatory has deployed their monster Precision Measuring Machine to digitize photographic plates covering the whole sky and creating the above map. Yellow corresponds to 150,000 stars per square degree, while dark blue corresponds to only 500 stars per square degree.

SN 1006: Supernova Remnant in X Rays
26.12.2005

This huge puff ball was once a star. One thousand years ago, in the year 1006, a new star was recorded in the sky that today we know was really an existing star exploding.

Cooling Neutron Star
5.03.2011

Supernova remnant Cassiopeia A (Cass A) is a comfortable 11,000 light-years away. Light from the Cass A supernova, the death explosion of a massive star, first reached Earth just 330 years ago.

The Pipe Nebula
23.11.2012

East of Antares, dark markings sprawl through crowded star fields toward the center of our Milky Way Galaxy. Cataloged in the early 20th century by astronomer E. E. Barnard, the obscuring interstellar dust clouds include B59, B72, B77 and B78, seen in silhouette against the starry background.

Centaurus A
19.11.2015

What's the closest active galaxy to planet Earth? That would be Centaurus A, only 11 million light-years distant. Spanning over 60,000 light-years, the peculiar elliptical galaxy is also known as NGC 5128.

GW Orionis: A Star System with Titled Rings
29.09.2020

Triple star system GW Orionis appears to demonstrate that planets can form and orbit in multiple planes. In contrast, all the planets and moons in our Solar System orbit in nearly the same plane. The picturesque system has three prominent stars, a warped disk, and inner tilted rings of gas and grit.

APOD: 2024 July 28 Б Sun Dance
28.07.2024

Sometimes, the surface of our Sun seems to dance. In the middle of 2012, for example, NASA's Sun-orbiting Solar Dynamic Observatory spacecraft imaged an impressive prominence that seemed to perform a running dive roll like an acrobatic dancer.

Chandra Deep Field
28.03.2001

Officially the Chandra Deep Field - South, this picture represents the deepest ever x-ray image of the Universe. One million seconds of accumulated exposure time with the orbiting Chandra X-ray Observatory went in to its making.

M51: The Whirlpool Galaxy in Dust and Stars
10.04.2001

The Whirlpool Galaxy is a classic spiral galaxy. At only 30 million light years distant and fully 60 thousand light years across, M51, also known as NGC 5194, is one of the brightest and most picturesque galaxies on the sky.