APOD: 2025 September 3 Б Cir X1: Jets in the Africa Nebula
3.09.2025

How soon do jets form when a supernova gives birth to a neutron star? The Africa Nebula provides clues. This supernova remnant surrounds Circinus X-1, an X-ray emitting neutron star and the companion star it orbits.

The Far 3kpc Arm
11.07.2008

A major discovery was lurking in the data. By accident, while preparing a talk on the Galaxy's spiral arms for a meeting of the American Astronomical Society, Tom Dame (Harvard-Smithsonian CfA) found it - a new spiral arm in the Milky Way.

Large Sunspot Group AR 9393
11.04.2001

The largest sunspot group of the past ten years crossed the surface of the Sun late last month and early this month. The group was designated Active Region 9393 as it was the 9393rd region identified since counting officially began in 1973.

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.

Water Discovered on the Moon
28.09.2009

Water has been discovered on the surface of the Moon. No lakes have been found, but rather NASA's Moon Mineralogy Mapper aboard India's new Chandrayaan-1 lunar orbiter radios back that parts of the Moon's surface absorb a very specific color of light identified previously only with water.

Centaurus As Warped Magnetic Fields
21.04.2021

When galaxies collide -- what happens to their magnetic fields? To help find out, NASA pointed SOFIA, its flying 747, at galactic neighbor Centaurus A to observe the emission of polarized dust -- which traces magnetic fields.

First Horizon Scale Image of a Black Hole
1.05.2022

What does a black hole look like? To find out, radio telescopes from around the Earth coordinated observations of black holes with the largest known event horizons on the sky. Alone, black holes are just black, but these monster attractors are known to be surrounded by glowing gas.

GRB 060218: A Mysterious Transient
27.02.2006

What is it? Something is happening in a small portion of the sky toward the constellation of Aries and telescopes around the globe are tracking an unusual transient there as it changes day by day. No one is sure what it will do next.

The Pulsar Powered Crab
5.09.1998

In the Summer of 1054 A.D. Chinese astronomers reported that a star in the constellation of Taurus suddenly became as bright as the full Moon. Fading slowly, it remained visible for over a year.

The Multiwavelength Crab
11.05.2017

The Crab Nebula is cataloged as M1, the first object on Charles Messier's famous list of things which are not comets. In fact, the Crab is now known to be a supernova remnant, expanding debris from massive star's death explosion, witnessed on planet Earth in 1054 AD.