Hubble reveals previously unseen shocks: This new, detailed, Hubble image shows a planetary nebula in the making of a proto-planetary nebula. A dying star (hidden behind dust and gas in the centre of the nebula) has ejected massive amounts of gas. Parts of the gas have reached tremendous velocities of up to one-and-a-half million kilometres per hour. Shown in blue is light from hydrogen and ionised nitrogen arising from supersonic shocks where the gas stream rams into the surrounding material. The image shows for the first time these complex gas structures which are predicted by theory. The Hubble image was taken shortly before Christmas 2000 with the WFPC2 instrument (Wide Field and Planetary Camera 2) in four different filters. Here, light from 791 nm is displayed in red (exposure time 900 s), 675 nm in green (900 s), while combined light from hydrogen (656 nm) and ionised nitrogen atoms (658 nm) are shown as blue (14, 700 s).

Name: Calabash Nebula, OH 231.8+4.2
Type: Milky Way : Nebula : Type : Planetary
Category: Nebulae
Constellation: Puppis
Distance: 4500 light years
Release date: 24 August 2001, 15:00
Credit: ESA & Valentin Bujarrabal (Observatorio Astronomico Nacional, Spain)

The Calabash Nebula and its surroundings (ground-based image): This image is from the Digitized Sky Survey II and shows half a degree of sky centred on the Calabash Nebula (indicated by the circle) also known as the Rotten Egg Nebula. The nebula is lying in the star cluster Messier 46 - seen in the lower right corner of the image. The astronomers are investigating if the Calabash Nebula may be interacting with the stars in the cluster. Also seen in the image is another planetary nebula (which appears as a dense white circle to the lower right of the Calabash Nebula). This nebula is unrelated to the Calabash Nebula.

Name: Calabash Nebula, Messier 46, NGC 2437, OH 231.8+4.2
Type: Milky Way : Star : Grouping : Cluster : OpenMilky Way : Nebula : Type : Planetary
Category: Nebulae
Distance: 4500 light years
Release date: 24 August 2001, 15:00
Credit: ESA, Valentin Bujarrabal (Observatorio Astronomico Nacional, Spain) and Digitized Sky Survey.

Hubble and Keck discover galaxy building block: This NASA/ESA Hubble Space Telescope image shows a newly discovered very small, faint galaxy 'building block' found via a unique collaboration between ground- and space-based telescopes. Hubble and the 10 metre Keck Telescopes in Hawaii joined forces using a galaxy cluster which acts as a gravitational lens to detect what scientists believe is one of the smallest and most distant objects ever found. The galaxy cluster Abell 2218 was used by a team of European and American astronomers led by Richard Ellis (Caltech, USA) in their systematic search for intrinsically faint distant star-forming systems. Without the help from this cluster's magnifying power (it magnifies by around 30 times) the galaxy building block would have been undetectable with present facilities. In the image to the right, the object is seen distorted into two nearly identical, very red 'images' by the gravitational lens. The image pair represents the magnified result of a single background object gravitationally lensed by Abell 2218 and viewed at a distance of 13.4 billion light-years. The intriguing object contains only one million stars, far fewer than a mature galaxy, and Ellis and co-workers believe it is very young. Such young star-forming systems of low mass at early cosmic times are likely to be the objects from which the mature galaxies around us today have formed. In the image to the left, the full overview of the galaxy cluster Abell 2218 is seen. This image was taken by Hubble in 1999 during the Early Release Observations made immediately after the Hubble Servicing Mission 3A.

Name: Abell 2218
Type: Early Universe : Galaxy : Grouping : Cluster
Category: Galaxies
Distance: z=0.17 (redshift)
Release date: 5 October 2001, 15:00
Credit: ESA, NASA, Richard Ellis (Caltech, USA) and Jean-Paul Kneib (Observatoire Midi-Pyrénées, France)

Hubble and Keck's newly discovered galaxy 'building block': This NASA/ESA Hubble Space Telescope image shows a newly discovered very small, faint galaxy 'building block' found via a unique collaboration between ground- and space-based telescopes. Hubble and the 10 metre Keck Telescopes in Hawaii joined forces using a galaxy cluster which acts as a gravitational lens to detect what scientists believe is one of the smallest and most distant objects ever found. The galaxy cluster Abell 2218 was used by a team of European and American astronomers led by Richard Ellis (Caltech, USA) in their systematic search for intrinsically faint distant star-forming systems. Without the help from this cluster's magnifying power (it magnifies by around 30 times) the galaxy building block would have been undetectable with present facilities. The object is seen distorted into two nearly identical, very red 'images' by the gravitational lens. The image pair represents the magnified result of a single background object gravitationally lensed by Abell 2218 and viewed at a distance of 13.4 billion light-years. The intriguing object contains only one million stars, far fewer than a mature galaxy, and Ellis and co-workers believe it is very young. Such young star-forming systems of low mass at early cosmic times are likely to be the objects from which the mature galaxies around us today have formed.

Name: Abell 2218
Type: Early Universe : Galaxy : Type : Gravitationally LensedEarly Universe : Galaxy : Grouping : Cluster
Category: Galaxies
Distance: z=0.17 (redshift)
Release date: 5 October 2001, 15:00
Credit: ESA, NASA, Richard Ellis (Caltech, USA) and Jean-Paul Kneib (Observatoire Midi-Pyrénées, France)

The galaxy cluster Abell 2218: This image shows the full overview of the galaxy cluster Abell 2218 and its gravitational lenses. This image was taken by Hubble in 1999 during the Early Release Observations made immediately after the Hubble Servicing Mission 3A.

Name: Abell 2218
Type: Early Universe : Galaxy : Type : Gravitationally LensedEarly Universe : Galaxy : Grouping : Cluster
Category: Galaxies
Constellation: Draco
Distance: z=0.17 (redshift)
Release date: 5 October 2001, 15:00
Credit: NASA, ESA, A. Fruchter and the ERO Team (STScI, ST-ECF )