Abell 370: Galaxy Cluster Gravitational Lens
27.08.2016

What is that strange arc? While imaging the cluster of galaxies Abell 370, astronomers had noted an unusual arc to the right of many cluster galaxies. Although curious, one initial response was to avoid commenting on the arc because nothing like it had ever been noted before.

Millions of Stars in Omega Centauri
20.02.1996

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.

M44: A Beehive of Stars
3.08.1998

M44 is a prominent open cluster of stars. Nicknamed Praesepe and "The Beehive", it is one of the few open clusters visible to the unaided eye. M44 was thought to be a nebula until Galileo used an early telescope to resolve the cluster's bright blue stars. These stars are visible in the above image.

NGC 4755: A Jewel Box of Stars
10.11.1996

The great variety of star colors in this open cluster underlie it's name: The Jewel Box. The bright central star Kappa Crucis is red, in contrast to the many blue stars that surround it. The cluster contains just over 100 stars, and might be no older than 10 million years.

Star Forming Region RCW38
6.12.1998

Star cluster RCW38 was hiding. This open cluster of stars is located about 5000 light years away towards the constellation of Vela. Looking there will not normally reveal most of the stars in this cluster, though.

Mars and the Beehive
9.06.2023

This month, bright Mars and brilliant Venus are the prominent celestial beacons in planet Earth's western skies after sunset. Wandering through the constellation Cancer the Crab, the Red Planet was captured here on the evening of June 3 near the stars of open cluster Messier 44.

Hot Gas In Hydra A
16.12.1999

The Hydra A galaxy cluster is really big. In fact, such clusters of galaxies are the largest gravitationally bound objects in the Universe. But individual galaxies are too cool to be recorded in this false-color Chandra Observatory X-ray image which shows only the 40 million degree gas that permeates the Hydra A cluster.

NGC 4755: A Jewel Box of Stars
18.06.2001

The great variety of star colors in this open cluster underlie its name: The Jewel Box. One of the bright central stars is a red supergiant, in contrast to the many blue stars that surround it. The cluster, also known as Kappa Crucis contains just over 100 stars, and is about 10 million years old.

Hercules Galaxies
27.08.1998

These are galaxies of the Hercules Cluster, an archipelago of "island universes" a mere 650 million light-years distant. This cluster is loaded with gas and dust rich, star forming, spiral galaxies but has relatively few elliptical galaxies, which lack gas and dust and the associated newborn stars.

Millions of Stars in Omega Centauri
15.06.2011

Featured in this sharp telescopic image, globular star cluster Omega Centauri (NGC 5139) is some 15,000 light-years away. Some 150 light-years in diameter, the cluster is packed with about 10 million stars much older than the Sun.