GK Per: Nova of 1901
5.11.2011

Early in the 20th century, GK Persei briefly became one of the brightest stars in planet Earth's sky, an event known as Nova Persei 1901. Documented in this modern day composite of two images from 2003 and 2011 the ejecta from the explosion, popularly called the Firework Nebula, continues to expand into space.

Reflections on vdB 31
10.03.2017

Riding high in the constellation of Auriga, beautiful, blue vdB 31 is the 31st object in Sidney van den Bergh's 1966 catalog of reflection nebulae. It shares this well-composed celestial still life with dark, obscuring clouds recorded in Edward E. Barnard's 1919 catalog of dark markings in the sky.

Massive Stars Resolved in the Carina Nebula
30.11.2008

How massive can stars be? Big, hefty stars live short violent lives that can profoundly affect their environments. Isolating a massive star can be problematic, however, since what seems to be a single bright star might actually turn out to be several stars close together.

Bright Spiral Galaxy M81
18.11.2014

One of the brightest galaxies in planet Earth's sky is similar in size to our Milky Way Galaxy: big, beautiful M81. This grand spiral galaxy can be found toward the northern constellation of the Great Bear (Ursa Major).

Messier 81
26.03.2025

One of the brightest galaxies in planet Earth's sky is similar in size to our Milky Way Galaxy: big, beautiful Messier 81. Also known as NGC 3031 or Bode's galaxy for its 18th century discoverer, this grand spiral can be found toward the northern constellation of Ursa Major, the Great Bear.

Resolving Mira
13.08.1997

Most stars appear only as points of light. Recently, Betelgeuse became the second star, after our Sun, to have it surface resolved. Now add Mira to the list. Mira A is a red giant star undergoing dramatic pulsations, causing it to become more than 100 times brighter over the course of a year.

Messier 81
16.04.2019

One of the brightest galaxies in planet Earth's sky is similar in size to our Milky Way Galaxy: big, beautiful Messier 81. Also known as NGC 3031 or Bode's galaxy for its 18th century discoverer, this grand spiral can be found toward the northern constellation of Ursa Major, the Great Bear.

M33: Spiral Galaxy in Triangulum
14.09.2006

The small, northern constellation Triangulum harbors this magnificent face-on spiral galaxy, M33. Its popular names include the Pinwheel Galaxy or just the Triangulum Galaxy. M33 is over 50,000 light-years in diameter, third largest in the Local Group of galaxies after the Andromeda Galaxy (M31), and our own Milky Way.

APOD: 2025 August 18 Б NGC 1309: A Useful Spiral Galaxy
17.08.2025

This galaxy is not only pretty -- it's useful. A gorgeous spiral some 100 million light-years distant, NGC 1309 lies on the banks of the constellation of the River (Eridanus). NGC 1309 spans about 30,000 light-years, making it about one third the size of our larger Milky Way galaxy.

Resolving Mira
20.01.2001

Most stars appear only as points of light. In 1995, Betelgeuse became the second star, after our Sun, to have it surface resolved. Later that year, Mira was added to the list. Mira...