The Observable Universe
16.03.2022

How far can you see? Everything you can see, and everything you could possibly see, right now, assuming your eyes could detect all types of radiations around you -- is the observable universe. In light...

The Galactic Ring of NGC 6782
21.11.2001

Do spiral galaxies look the same in every color? NGC 6782 demonstrates colorfully that they do not. In visible light, NGC 6782 appears to be a normal spiral galaxy with a bright bar across its center.

APOD: 2024 August 12 Б Perseid Meteors over Stonehenge
12.08.2024

What's happening in the sky above Stonehenge? A meteor shower: specifically, the Perseid meteor shower. A few nights ago, after the sky darkened, many images of meteors from this year's Perseids were captured separately and merged into a single frame.

Unusual Gas Filaments Surround Galaxy NGC 1275
25.07.2005

How were the unusual gas filaments surrounding galaxy NGC 1275 created? No one is sure. Galaxy NGC 1275 is the central dominant galaxy of the Perseus Cluster of Galaxies, a cluster with many member galaxies visible in the above image. In visible light, NGC 1275 appears to show a spectacular collision between two distinct galaxies.

APOD: 2025 April 9 Б HH 49: Interstellar Jet from Webb
9.04.2025

What's at the tip of this interstellar jet? First let's consider the jet: it is being expelled by a star system just forming and is cataloged as Herbig-Haro 49 (HH 49). The star system expelling this jet is not visible -- it is off to the lower right.

Shell Game in the LMC
29.12.2016

An alluring sight in southern skies, the Large Magellanic Cloud (LMC) is seen here through narrowband filters. The filters are designed to transmit only light emitted by ionized sulfur, hydrogen, and oxygen atoms. Ionized...

Shell Game in the LMC
18.05.2006

An alluring sight in dark southern skies, the Large Magellanic Cloud (LMC) is seen here through a narrow filter that transmits only the red light of hydrogen atoms. Ionized by energetic starlight, a hydrogen atom emits the characteristic red H-alpha light as its single electron is recaptured and transitions to lower energy states.

The Giant Radio Lobes of Fornax A
28.06.2005

Together, the radio lobes span over one million light years -- what caused them? In the center is a large but peculiar elliptical galaxy dubbed NGC 1316. Detailed inspection of the NGC 1316 system indicates that it began absorbing a small neighboring galaxy about 100 million years ago.

The Tarantula Nebula from SuperBIT
27.04.2023

The Tarantula Nebula, also known as 30 Doradus, is more than a thousand light-years in diameter, a giant star forming region within nearby satellite galaxy the Large Magellanic Cloud. About 160 thousand light-years away, it's the largest, most violent star forming region known in the whole Local Group of galaxies.

A Gemini Sky
9.09.2003

Where will Gemini take us tonight? It is dusk and Gemini North, one of the largest telescopes on planet Earth, prepares to peer into the distant universe. Gemini's flexible 8.1-mirror has taken...