X Ray Stars of 47 Tuc
21.07.2005

Visible light images show the central region of globular cluster 47 Tucanae is closely packed, with stars less than a tenth of a light-year apart. This Chandra false-color x-ray view of central...

Arp 240: A Bridge between Spiral Galaxies from Hubble
27.11.2016

Why is there a bridge between these two spiral galaxies? Made of gas and stars, the bridge provides strong evidence that these two immense star systems have passed close to each other and experienced violent tides induced by mutual gravity.

NGC6366 vs 47 Ophiuchi
22.05.2025

Most globular star clusters roam the halo of our Milky Way galaxy, but globular cluster NGC 6366 lies close to the galactic plane. About 12,000 light-years away toward the constellation Ophiuchus, the cluster's starlight is dimmed and reddened by the Milky Way's interstellar dust when viewed from planet Earth.

Explosions from White Dwarf Star RS Oph
21.08.2021

Spectacular explosions keep occurring in the binary star system named RS Ophiuchi. Every 20 years or so, the red giant star dumps enough hydrogen gas onto its companion white dwarf star to set off a brilliant thermonuclear explosion on the white dwarf's surface.

The Red Square Nebula
25.09.2021

How did a round star create this square nebula? No one is quite sure. The round star, known as MWC 922 and possibly part of a multiple star system, appears at the center of the Red Square Nebula. The featured image combines infrared exposures from the Hale Telescope on Mt.

APOD: 2004 August 27- The Sedna Scenario
27.08.2004

The discovery of Sedna (aka 2003 VB12), the most distant known object orbiting the Sun, presents a mystery. Pluto's orbit averages about 40 AU in radius, where an AU (Astronomical Unit) is the Earth-Sun distance.

RCW 86: Historical Supernova Remnant
2.03.2023

In 185 AD, Chinese astronomers recorded the appearance of a new star in the Nanmen asterism. That part of the sky is identified with Alpha and Beta Centauri on modern star charts. The new star was visible to the naked-eye for months, and is now thought to be the earliest recorded supernova.

Eta Car: 3D Model of the Most Dangerous Star Known
8.02.2022

What's the most dangerous star near earth? Many believe it's Eta Carinae, a binary star system about 100 times the mass of the Sun, just 10,000 light years from earth.

NGC 4650A: Strange Galaxy and Dark Matter
25.06.1998

This strangely distorted galaxy of stars is cataloged as NGC 4650A. It lies about 165 million light-years away in the southern constellation Centaurus. The complex system seems to have at least two parts, a flattened disk of stars with a dense, bright, central core and a sparse, sharply tilted ring of gas, dust and stars.

3I/ATLAS: A View from Planet Earth
20.11.2025

Now outbound after its perihelion or closest approach to the Sun on October 29, Comet 3I/ATLAS is only the third known interstellar object to pass through our fair Solar System. Its greenish coma...