Henrietta Leavitt Calibrates the Stars
3.09.2000

Humanity's understanding of the relative brightness and variability of stars was revolutionized by the work of Henrietta Swan Leavitt (1868-1921). Working at Harvard College Observatory, Leavitt precisely calibrated the photographic magnitudes of 47 stars to which all other stars could be compared.

Symbiotic Star System R Aquarii
4.01.1996

Sometimes stars work together to create a spectacular display. Such is the case with the binary star system R Aquarii - a "symbiotic" star system. Here two stars, a variable giant and a white dwarf companion - create both a nebula and a jet.

Henrietta Leavitt Calibrates the Stars
27.10.1998

Humanity's understanding of the relative brightness and variability of stars was revolutionized by the work of Henrietta Swan Leavitt (1868-1921). Working at Harvard College Observatory, Leavitt precisely calibrated the photographic magnitudes of 47 stars to which all other stars could be compared.

Central Galactic Star Bursts
1.10.1995

The pictured core of the galaxy NGC 253 shows an exceptionally high rate of star formation. In the center are some of the densest knots of stars ever found, surrounded by glowing gas and dust lanes. Galaxies where such high star formation rates are seen are called "starburst" galaxies.

Millions of Stars in Omega Centauri
21.02.1996

Pictured above is the largest ball of stars in our Galaxy. About 10 million stars orbit the center of this globular cluster - named Omega Centauri - as this giant globular cluster orbits the center of our Galaxy.

M45: The Pleiades Star Cluster
18.11.2007

Perhaps the most famous star cluster on the sky, the Pleiades can be seen without binoculars from even the depths of a light-polluted city. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and closest open clusters.

The Launch of STARDUST
5.04.1999

NASA launches powerful rockets. One such rocket, the Delta II, recently lofted the STARDUST mission into the nearby Solar System. STARDUST is expected to photograph Comet Wild in 2004 as it zooms by, and return interstellar dust samples to Earth in 2006.

A Wolf Rayet Star Bubble
28.09.1997

What's a Wolf-Rayet star, and how did it create that spherical bubble and sweeping arc? A Wolf-Rayet star is a star that originated with a mass over 40 times that of our Sun.

A Wolf-Rayet Star Bubble
26.08.1996

What's a Wolf-Rayet star, and how did it create that spherical bubble and sweeping arc? A Wolf-Rayet star is a star that originated with a mass over 40 times that of our Sun.

The Pleiades Star Cluster
1.12.2002

It is the most famous star cluster on the sky. The Pleiades can be seen without binoculars from even the depths of a light-polluted city. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and closest open clusters.