At the Center of the Milk Way
23.10.2005

At the center of our Milky Way Galaxy lies a black hole with over 2 million times the mass of the Sun. Once a controversial claim, this astounding conclusion is now virtually inescapable and based on observations of stars orbiting very near the galactic center.

Mira Over Germany
21.02.2007

What's that new star in the sky? The star might appear new, but it's actually just the variable star Mira near its brightest. Rolling your cursor over the above vertically compressed image...

Black Hole Candidate Cygnus X 1
11.08.2008

Is that a black hole? Quite possibly. The Cygnus X-1 binary star system contains one of the best candidates for a black hole. The system was discovered because it is one of the brightest...

Cancri 55 e: Climate Patterns on a Lava World
5.04.2016

Why might you want to visit super-earth Cancri 55 e? Its extremely hot climate would be a deterrent, as mornings on this world might bring fresh lava flows. Discovered in 2004, the planet Cancri 55 e has twice the diameter of our Earth and about 10 times Earth's mass.

GL 105C: The Coolest Star?
20.09.1995

Is the dim star to the upper right of this false-color picture the coolest possible normal star? From this recent picture by the Hubble Space Telescope, astronomers have estimated its mass is just high enough for it to fuse hydrogen into helium in its core.

A View from Next Door
18.10.2012

Located just next door, Alpha Centauri is the closest star system to the Sun. A view from our interstellar neighbor a mere 4.3 light-years away is shown in this illustration. The Sun is at the upper right, a bright star against the background of the Milky Way.

M31 versus M33
26.09.2015

Separated by about 14 degrees (28 Full Moons) in planet Earth's sky, spiral galaxies M31 at left, and M33 are both large members of the Local Group, along with our own Milky Way galaxy.

From California to the Pleiades
22.11.2013

An astronomical trip from the California Nebula to the Pleiades star cluster would cover just 12 degrees across planet Earth's night sky. That's equivalent to the angular extent of 25 Full Moons, as your telescope sweeps over the borders of the constellations Perseus and Taurus.

Comet PanSTARRS is near the Edge
16.02.2018

The comet PanSTARRS, also known as the blue comet (C/2016 R2), really is near the lower left edge of this stunning, wide field view recorded on January 13. Spanning nearly 20 degrees on the sky, the cosmic landscape is explored by well-exposed and processed frames from a sensitive digital camera.

APOD: 2025 October 10 Б 50 Light-years to 51 Pegasi
10.10.2025

It's only 50 light-years to 51 Pegasi. That star's position is indicated in this snapshot from August 2025, taken on a night with mostly brighter stars visible above the dome at Observatoire de Haute-Provence in France.