In the Heart of the Heart Nebula
14.02.2022

What excites the Heart Nebula? First, the large emission nebula dubbed IC 1805 looks, in whole, like a human heart. Its shape perhaps fitting of the Valentine's Day, this heart glows brightly in red light emitted by its most prominent element: excited hydrogen.

Stars Without Galaxies
15.02.1998

Galaxies are made up of stars, but are all stars found within galaxies? Using the Hubble Space Telescope, researchers exploring the Virgo Cluster of galaxies have now found about 600 red giant stars adrift in intergalactic space. Above is an artist's vision of the sky from a hypothetical planet of such a lonely sun.

M24: A Sagittarius Starscape
21.09.2004

Many vast star fields in the plane of our Milky Way Galaxy are rich in clouds of dust, and gas. First and foremost, visible in the above picture are millions of stars, many of which are similar to our Sun.

NGC 281: Cluster, Clouds, and Globules
20.10.2004

NGC 281 is a busy workshop of star formation. Prominent features include a small open cluster of stars, a diffuse red-glowing emission nebula, large lanes of obscuring gas and dust, and dense knots of dust and gas in which stars may still be forming.

In the Heart of the Heart Nebula
14.02.2018

What's that inside the Heart Nebula? First, the large emission nebula dubbed IC 1805 looks, in whole, like a human heart. It's shape perhaps fitting of the Valentine's Day, this heart glows brightly in red light emitted by its most prominent element: hydrogen.

APOD: 2025 February 25 Б M41: The Little Beehive Star Cluster
25.02.2025

Why are there so many bright blue stars? Stars are usually born in clusters, and the brightest and most massive of these stars typically glow blue. Less-bright, non-blue stars like our Sun surely also exist in this M41 star cluster but are harder to see. A few bright orange-appearing red giant stars are visible.

Orion's Horsehead Nebula
25.09.1995

The black indentation to the red emission nebula seen just to the right of center of the above photograph is one of the most famous features in any nebulae on the sky. Because of its shape, it is known as the Horsehead Nebula.

APOD: 2002 September 18- A Sagittarius Starscape
18.09.2002

Many vast star fields in the plane of our Milky Way Galaxy are rich in clouds of stars, dust, and gas. First and foremost, visible in the above picture are millions of stars, many of which are similar to our Sun.

APOD: 2024 June 11 Б Colorful Stars and Clouds near Rho Ophiuchi
11.06.2024

Why is the sky near Antares and Rho Ophiuchi so colorful, yet dusty? The colors result from a mixture of objects and processes. Fine dust -- illuminated by starlight -- produces blue reflection nebulae. Gaseous clouds whose atoms are excited by ultraviolet starlight produce reddish emission nebulae. Backlit dust clouds block starlight and so appear dark.

Sharpless 212 in Hydrogen and Sulfur
18.12.2001

Where do the most massive stars form? Observational evidence indicates that the outskirts of developing open clusters of stars are primary locations. Pictured above is one such open cluster: Sharpless 212. Visible in the image center are massive stars in the open cluster.