Light Echoes from V838 Mon
22.11.2009

What caused this outburst of V838 Mon? For reasons unknown, star V838 Mon's outer surface suddenly greatly expanded with the result that it became the brightest star in the entire Milky Way Galaxy in January 2002. Then, just as suddenly, it faded.

Violent Sunspot Group AR 1302 Unleashes a Flare
28.09.2011

One of the most active sunspot groups in years is currently crossing the Sun. AR 1302 first came around the Sun's edge last week and is so large it can be seen without a telescope.

NGC 1333: Stellar Nursery in Perseus
5.11.2015

NGC 1333 is seen in visible light as a reflection nebula, dominated by bluish hues characteristic of starlight reflected by interstellar dust. A mere 1,000 light-years distant toward the heroic constellation Perseus, it lies at the edge of a large, star-forming molecular cloud.

The Galactic Center in Radio from MeerKAT
8.07.2019

What's happening at the center of our galaxy? It's hard to tell with optical telescopes since visible light is blocked by intervening interstellar dust. In other bands of light, though, such as radio, the galactic center can be imaged and shows itself to be quite an interesting and active place.

Iron in the Butterfly Nebula
21.07.2020

Can stars, like caterpillars, transform themselves into butterflies? No, but in the case of the Butterfly Nebula -- it sure looks like it. Though its wingspan covers over 3 light-years and its estimated surface temperature...

APOD: 2025 September 10 Б The Great Lacerta Nebula
10.09.2025

It is one of the largest nebulas on the sky -- why isn't it better known? Roughly the same angular size as the Andromeda Galaxy, the Great Lacerta Nebula can be found toward the constellation of the Lizard (Lacerta).

The Bay of Rainbows
12.02.2026

Dark, smooth regions that cover the Moon's familiar face are called by Latin names for oceans and seas. That naming convention is historical, though it may seem a little ironic to denizens...

Moon Mare and Montes
28.12.2000

This arresting image of the third quarter moon in the excellent skies above the Pine Crest Farm Observatory, Dell Prairie, Wisconsin, was recorded with a 24 inch telescope and digital camera on October 19.

The International Ultraviolet Explorer
29.09.1995

The International Ultraviolet Explorer (IUE) was launched by a NASA Delta rocket in 1978 to provide a space telescope for ultraviolet astronomy. A collaborative project among NASA, ESA and the British SRC (now PPARC) agencies, IUE's estimated lifetime was 3 to 5 years.

Denizen of the Tarantula Nebula
3.05.2003

The star cluster at lower right, cataloged as Hodge 301, is a denizen of the Tarantula Nebula. An evocative nebula in the southern sky, the sprawling cosmic Tarantula is an energetic star forming region some 168,000 light-years distant in our neighboring galaxy the Large Magellanic Cloud.