Comet Halley's Nucleus
10.12.1996

Here is what a comet nucleus really looks like. For all active comets except Halley, it was only possible to see the surrounding opaque gas cloud called the coma. During Comet Halley's most...

APOD: 2023 December 24 Б NGC 2440: Cocoon of a New White Dwarf
24.12.2023

What's that in the center? Like a butterfly, a white dwarf star begins its life by casting off a cocoon of gas that enclosed its former self. In this analogy, however, the Sun would be a caterpillar and the ejected shell of gas would become the prettiest cocoon of all.

NGC 2440: Pearl of a New White Dwarf
17.05.2015

Like a pearl, a white dwarf star shines best after being freed from its shell. In this analogy, however, the Sun would be a mollusk and its discarded hull would shine prettiest of all!

M51: The Center Of The Whirlpool
27.05.2000

In the center of M51, a spiral galaxy 23 million light-years away, astronomers have identified a dense region of young stars. Viewed face-on in the constellation Canes Venatici, the swirling arcs of this galaxy's spiral arms have inspired its popular name, The Whirlpool Galaxy.

LINEAR s Tail and Two Nuclei
31.05.2001

Arcing toward southern skies in late March, this faint comet LINEAR - the one officially designated C/2001 A2 (LINEAR) - brightened unexpectedly. The outburst, apparently due to the fragmentation of its nucleus, delighted observers as the comet eventually increased to naked-eye brightness.

Fragments of Comet LINEAR
11.08.2000

What do you call a bunch of comet fragments anyway ... a flock, a covey, a swarm? The question is definitely relevant to comet LINEAR (C/1999 S4 LINEAR) whose nucleus apparently fragmented late last month during its first trip through the inner solar system.

Near Comet Hyakutake's Nucleus
21.03.1996

This March 19th false-color picture of Comet Hyakutake from one of the most sophisticated ground based telescopes captures the area surrounding the comet's nucleus. A comet's nucleus - not directly visible here - is a solid dirty iceball probably no more than 10 kilometers across.

The Nucleus of Comet Tempel 1
15.09.2005

Approaching the nucleus of comet Tempel 1 at ten kilometers per second, the Deep Impact probe's targeting camera recorded a truly dramatic series of images. Successive pictures improve in resolution and have been...

Expansive Comet Holmes
21.11.2007

The spherical coma of Comet Holmes has swollen to a diameter of over 1.4 million kilometers, making the tenuous, dusty cloud even bigger than the Sun. Scattering sunlight, all that dust and gas came...

NGC 2440: Cocoon of a New White Dwarf
7.05.2006

Like a butterfly, a white dwarf star begins its life by casting off a cocoon that enclosed its former self. In this analogy, however, the Sun would be a caterpillar and the ejected shell of gas would become the prettiest of all!