Colorful Clouds Near Rho Ophiuchi
6.07.2015

Why is the sky near Antares and Rho Ophiuchi so colorful? The colors result from a mixture of objects and processes. Fine dust illuminated from the front 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.

NGC 7293: The Helix Nebula
14.10.2021

A mere seven hundred light years from Earth, toward the constellation Aquarius, a sun-like star is dying. Its last few thousand years have produced the Helix Nebula (NGC 7293), a well studied and nearby example of a Planetary Nebula, typical of this final phase of stellar evolution.

APOD: 2024 November 25 Б The Horsehead Nebula
25.11.2024

One of the most identifiable nebulas in the sky, the Horsehead Nebula in Orion, is part of a large, dark, molecular cloud. Also known as Barnard 33, the unusual shape was first discovered on a photographic plate in the late 1800s.

APOD: 2024 December 1 Б Cosmic Latte: The Average Color of the Universe
1.12.2024

What color is the universe? More precisely, if the entire sky were smeared out, what color would the final mix be? This whimsical question came up when trying to determine what stars are commonplace in nearby galaxies. The answer, depicted here, is a conditionally perceived shade of beige. In computer parlance: #FFF8E7.

Fomalhaut Dust Disk Indicates Planets
11.10.2002

One of the brightest stars on the sky likely has planets. Fomalhaut, actually the 17th brightest star in the night sky, is a mere 22 light-years away but only a fraction of the age of our Sun.

Orion's Horsehead Nebula
25.10.1997

The Horsehead Nebula is one of the most famous nebulae on the sky. It is visible as the black indentation to the red emission nebula seen just to the right of center of the above photograph. The bright star near the center is located in the belt of the familiar constellation of Orion.

M57: The Ring Nebula
4.05.1998

It looked like a ring on the sky. Hundreds of years ago astronomers noticed a nebula with a most unusual shape. Now known as M57 or NGC 6720, the gas cloud became popularly known as the Ring Nebula.

NGC 1579: Trifid of the North
25.05.2006

Colorful NGC 1579 resembles the better known Trifid Nebula, but lies much farther north in planet Earth's sky, in the heroic constellation Perseus. About 2,100 light-years away and 3 light-years across, NGC 1579 is a captivating study in color.

The Rosette Nebula in Hydrogen, Oxygen, and Sulfur
11.01.2000

The Rosette Nebula is a large emission nebula located 3000 light-years away. The great abundance of hydrogen gas gives NGC 2237 its red color in most photographs. The wind from the open cluster of stars known as NGC 2244 has cleared a hole in the nebula's center.

The Tidal Tail of NGC 3628
27.07.2007

A mere 30 million light-years away, large spiral galaxy NGC 3628 (center) shares its neighborhood in the local Universe with two other large spirals, in a magnificent grouping otherwise known as the Leo Triplett.