A Backward Sunspot and the New Solar Cycle
30.08.2006

Why is sunspot 905 backwards? Perhaps it is a key marker for the beginning of a new magnetic cycle on our Sun. Every 11 years, our Sun goes through a magnetic cycle, at the end of which its overall magnetic orientation is reversed.

APOD: 2025 August 22 Б A Tale of Two Nebulae
22.08.2025

This colorful telescopic view towards the musical northern constellation Lyra reveals the faint outer halos and brighter central ring-shaped region of M57, popularly known as the Ring Nebula. To modern astronomers M57 is a well-known planetary nebula.

Around The Arches Cluster
14.06.2001

The most compact cluster of stars known in our galaxy, the Arches cluster, boasts 100 or so massive, young stars contained within a diameter of one light-year. Seen toward the constellation Sagittarius, the Arches...

SN 2006GY: Brightest Supernova
10.05.2007

The stellar explosion cataloged as supernova SN 2006gy shines in this wide-field image (left) of its host galaxy, NGC 1260, and expanded view (upper right panel) of the region surrounding the galaxy's core.

UHZ1: Distant Galaxy and Black Hole
10.11.2023

Dominated by dark matter, massive cluster of galaxies Abell 2744 is known to some as Pandora's Cluster. It lies 3.5 billion light-years away toward the constellation Sculptor. Using the galaxy cluster's enormous...

Julius Caesar and Leap Days
29.02.2004

Today, February 29th, is a leap day - a relatively rare occurrence. In 46 BC, Julius Caesar, pictured above in a self-decreed minted coin, created a calendar system that added one leap day every four years.

X-Ray Ring Around SN1987A
12.05.2000

This false-color image from the Chandra X-ray Observatory reveals a one light-year diameter ring of hot, ten million degree plasma. It is one of the most detailed X-ray images of the expanding blast wave from supernova 1987A (SN1987A).

A Historic Brazilian Constellation
12.01.2021

The night sky is filled with stories. Cultures throughout history have projected some of their most enduring legends onto the stars above. Generations of people see these stellar constellations, hear the associated stories, and pass them down.

Saturn-Sized Worlds Discovered
30.03.2000

The last decade saw the profound discovery of many worlds beyond our solar system, but none analogs of our home planet Earth. Exploiting precise observational techniques, astronomers inferred the presence of well over two dozen extrasolar planets, most nearly as massive as gas giant Jupiter or more, in close orbits around sun-like stars.

Messier 106
9.04.2021

Close to the Great Bear (Ursa Major) and surrounded by the stars of the Hunting Dogs (Canes Venatici), this celestial wonder was discovered in 1781 by the metric French astronomer Pierre Mechain. Later, it was added to the catalog of his friend and colleague Charles Messier as M106.