The Once and Future Stars of Andromeda
20.01.2011

The big, beautiful Andromeda Galaxy, aka M31, is a spiral galaxy a mere 2.5 million light-years away. Two space-based observatories have combined to produce this intriguing composite image of Andromeda, at wavelengths outside the visible spectrum. The remarkable view follows the locations of this galaxy's once and future stars.

IC 4406: A Seemingly Square Nebula
8.01.2017

How can a round star make a square nebula? This conundrum comes to light when studying planetary nebulae like IC 4406. Evidence indicates that IC 4406 is likely a hollow cylinder, with its square appearance the result of our vantage point in viewing the cylinder from the side.

Venus Evening Loop
1.06.2001

From September 2000 through March 2001, astronomer Tunc Tezel patiently photographed the planet Venus on 25 different dates as it wandered through the evening twilight. The pictures were taken from the same spot...

Hubble Remix: Active Galaxy NGC 1275
4.06.2010

Active galaxy NGC 1275 is the central, dominant member of the large and relatively nearby Perseus Cluster of Galaxies. Wild-looking at visible wavelengths, the active galaxy is also a prodigious source of x-rays and radio emission.

APOD: 2024 February 27 Б Supernova Remnant Simeis 147
27.02.2024

It's easy to get lost following the intricate, looping, and twisting filaments of supernova remnant Simeis 147. Also cataloged as Sharpless 2-240, the filamentary nebula goes by the popular nickname the Spaghetti Nebula.

The Umbra of Earth
26.01.2019

The dark, inner shadow of planet Earth is called the umbra. Shaped like a cone extending into space, it has a circular cross section most easily seen during a lunar eclipse. For example...

Earth at Night
9.07.2017

Can you find your favorite country or city? Surprisingly, on this world-wide nightscape, city lights make this task quite possible. Human-made lights highlight particularly developed or populated areas of the Earth's surface, including the seaboards of Europe, the eastern United States, and Japan.

APOD: 2023 September 17 Б Moon Mountains Magnified during Ring of Fire Eclipse
17.09.2023

What are those dark streaks in this composite image of a solar eclipse? They are reversed shadows of mountains at the edge of the Moon. The center image, captured from Xiamen, China, has the Moon's center directly in front of the Sun's center.

The Tulip in the Swan
14.11.2014

Framing a bright emission region this telescopic view looks out along the plane of our Milky Way Galaxy toward the nebula rich constellation Cygnus the Swan. Popularly called the Tulip Nebula the glowing cloud of interstellar gas and dust is also found in the 1959 catalog by astronomer Stewart Sharpless as Sh2-101.

APOD: 2023 September 13 Б NGC 4632: Galaxy with a Hidden Polar Ring
13.09.2023

Galaxy NGC 4632 hides a secret from optical telescopes. It is surrounded by a ring of cool hydrogen gas orbiting at 90 degrees to its spiral disk. Such polar ring galaxies have previously been discovered using starlight. However, NGC 4632 is among the first in which a radio telescope survey revealed a polar ring.