X Ray Moon and X Ray Star
9.09.2000

An x-ray star winks out behind the Moon in these before (left) and after views of a lunar occultation of the galactic x-ray source designated GX5-1. The false color images were made using data from the ROSAT (ROentgen SATellite), orbiting observatory.

X-ray Moon and X-ray Star
26.02.1996

An X-ray star winks out behind the Moon in these before and after views of a lunar occultation of the galactic X-ray source designated GX5-1. The false color images were made using data...

The Crab Nebula in X Rays
29.09.1999

Why does the Crab Nebula still glow? In the year 1054 A.D. a supernova was observed that left a nebula that even today glows brightly in every color possible, across the entire electromagnetic spectrum. At the nebula's center is an ultra-dense neutron star that rotates 30 times a second.

M1: The Exploding Crab Nebula
21.11.1995

The Crab Nebula resulted from a star that exploded - a supernova. The outer layers of the star were thrown violently into space, while the inner core collapsed to form a neutron star. This neutron...

A Dark Pulsar in CTA 1
21.10.2008

Where's the pulsar? Previously, the nebula CTA 1 showed an expanding supernova remnant, a jet, and a point source expected to be a pulsar -- a rotating neutron star producing pulses at radio energies. But no radio pulses were detected.

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...

Fifty Gravitational Wave Events Illustrated
3.11.2020

Over fifty gravitational wave events have now been detected. These events mark the distant, violent collisions of two black holes, a black hole and a neutron star, or two neutron stars. Most of the 50 events were detected in 2019 by the LIGO gravitational wave detectors in the USA and the VIRGO detector in Europe.

The Crab Nebula in Blue and White
11.07.2000

The Crab Nebula is a complex shell of expanding gas. The Crab Nebula formed from a star that was seen to explode in a supernova about 1000 years ago. This two color composite image taken with the WIYN 3.5-meter telescope shows in great detail filamentary structure of the glowing hydrogen gas.

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.

Oddities of Star Cluster NGC 6397
19.02.2002

One of these stars is blinking. This star, a member of globular cluster NGC 6397, is noteworthy not just because it blinks, but because it blinks so fast and because its companion star is so atypical.