Star Colors in Orion
11.02.2011

What determines a star's color? Its temperature. Red stars are cool, with surface temperatures of around 3,000 kelvins (K), while blue stars are hotter and can have temperatures over 30,000 K. Our own lovely "yellow" Sun's temperature is a comforting 6,000 K.

The Outburst Clouds of Star AG Car
26.05.2021

What created these unusual clouds? At the center of this 2021 Hubble image sits AG Carinae, a supergiant star located about 20,000 light-years away in the southern constellation Carina. The star's emitted...

Quadruple Lunar Halo Over Winter Road
2.01.2022

Sometimes falling ice crystals make the atmosphere into a giant lens causing arcs and halos to appear around the Sun or Moon. One Saturday night in 2012 was just such a time near Madrid, Spain, where a winter sky displayed not only a bright Moon but four rare lunar halos.

M44: The Beehive Cluster
30.04.2022

A mere 600 light-years away, M44 is one of the closest star clusters to our solar system. Also known as the Praesepe or the Beehive cluster its stars are young though, about 600 million years old compared to our Sun's 4.5 billion years.

The Black Hole in the Milky Way
2.11.2012

At the center of our Milky Way Galaxy, a mere 27,000 light-years away, lies a black hole with 4 million times the mass of the Sun. Fondly known as Sagittarius A* (pronounced A-star)...

ISON, Mars, Regulus
17.10.2013

In order top to bottom this celestial snapshot features Comet ISON, planet Mars, and Regulus, alpha star of the constellation Leo, in the same frame. The scene spans about 2 degrees near the eastern horizon in early morning skies of October 15.

LL Orionis: When Cosmic Winds Collide
15.11.2003

This arcing, graceful structure is actually a bow shock about half a light-year across, created as the wind from young star LL Orionis collides with the Orion Nebula flow. Adrift in Orion's stellar...

Zarmina s World
1.10.2010

A mere 20 light-years away in the constellation Libra, red dwarf star Gliese 581 has received much scrutiny by astronomers in recent years. Earthbound telescopes had detected the signatures of multiple planets orbiting...

Nearby Cepheid Variable RS Pup
9.09.2013

It is one of the most important stars in the sky. This is partly because, by coincidence, it is surrounded by a dazzling reflection nebula. Pulsating RS Puppis, the brightest star in the image center, is some ten times more massive than our Sun and on average 15,000 times more luminous.

M82 s Middle Mass Black Hole
14.09.2000

Black holes are probably the most bizarre creatures in the modern astronomical zoo. And after years of pondering black holes as either stellar mass objects seen in binary star systems or enormous supermassive black holes at the centers of galaxies, astronomers now have strong evidence