Probing the distant Universe for young galaxies: This Hubble Space Telescope image shows 28 of the more than 500 young galaxies that existed when the universe was less than 1 billion years old. The galaxies were uncovered in a study of two of the most distant surveys of the cosmos, the Hubble Ultra Deep Field (HUDF), completed in 2004, and the Great Observatories Origins Deep Survey (GOODS), made in 2003. Just a few years ago, astronomers had not spotted any galaxies that existed significantly less than 1 billion years after the Big Bang. The galaxies spied in the HUDF and GOODS surveys are blue galaxies brimming with star birth. The large image at left shows the Hubble Ultra Deep Field, taken by the Hubble telescope. The numbers next to the small blue boxes correspond to close-up views of 28 of the newly found galaxies at right. The galaxies in the postage-stamp size images appear red because of their tremendous distance from Earth. The blue light from their young stars took nearly 13 billion years to arrive at Earth. During the journey, the blue light was shifted to red light due to the expansion of space.

Name: Hubble Ultra Deep Field, HUDF
Type: Early Universe : Galaxy : Grouping : Cluster
Category: Galaxies
Release date: 21 September 2006, 16:00
Credit: NASA, ESA, R. Bouwens and G. Illingworth (University of California, Santa Cruz, USA)

Hubble Ultra Deep Field: This view of nearly 10,000 galaxies is called the Hubble Ultra Deep Field. The snapshot includes galaxies of various ages, sizes, shapes, and colours. The smallest, reddest galaxies, about 100, may be among the most distant known, existing when the universe was just 800 million years old. The nearest galaxies - the larger, brighter, well-defined spirals and ellipticals - thrived about 1 billion years ago, when the cosmos was 13 billion years old. The image required 800 exposures taken over the course of 400 Hubble orbits around Earth. The total amount of exposure time was 11.3 days, taken between Sept. 24, 2003 and Jan. 16, 2004.

Name: Hubble Ultra Deep Field, HUDF
Type: Early Universe : Galaxy : Grouping : Cluster
Category: Galaxies
Constellation: Fornax
Release date: 21 September 2006, 16:00
Credit: NASA, ESA, and S. Beckwith (STScI) and the HUDF Team

Details of individual distant galaxies: Astronomers analyzing two of the deepest views of the cosmos made with the NASA/ESA Hubble Space Telescope have uncovered a gold mine of galaxies, more than 500 that existed less than a billion years after the Big Bang. These galaxies thrived when the cosmos was less than 7 percent of its present age of 13.7 billion years. This sample, of which 28 are seen here, represents the most comprehensive compilation of galaxies in the early Universe, researchers said. The galaxies appear red because of their tremendous distance from Earth. The blue light from their young stars took nearly 13 billion years to arrive at Earth. During the journey, the blue light was shifted to red light due to the expansion of space.

Name: Hubble Ultra Deep Field, HUDF
Type: Early Universe : Galaxy : Grouping : Cluster
Category: Galaxies
Release date: 21 September 2006, 16:00
Credit: NASA, ESA, R. Bouwens and G. Illingworth (University of California, Santa Cruz, USA)

Hubble extrasolar planet search field in Sagittarius: This is an image of one-half of the Hubble Space Telescope field of view in the Sagittarius Window Eclipsing Extrasolar Planet Search (SWEEPS). The field contains approximately 150,000 stars, down to 30th magnitude. The stars in the Galactic disk and bulge have a mixture of colours and masses. The field is so crowded with stars because Hubble was looking across 26,000 light-years of space in the direction of the centre of our Galaxy. Half of these stars are bright enough for Hubble to monitor for any small, brief and periodic dips in brightness caused by the passage of an extrasolar planet passing in front of the star, an event called a transit. Hubble took approximately 520 pictures of this field, at red and blue wavelengths, 22 to 29 February, 2004. The green circles identify 9 stars that are orbited by planets with periods of a few days. Planets so close to their stars with such short orbital periods are called "hot Jupiters." These are considered "candidate" extrasolar planets because most of them are too faint to allow for spectroscopic observations that would allow for a precise measure of the planet's mass. The Hubble observations allow for a robust statistical estimate of the possible "false positives", which suggests that at least 45 percent of the candidates must be genuine planets. The bottom frame identifies one of two stars in the field where astronomers were able to spectroscopically measure the star's back-and-forth wobble due to the pull of the planet. The planet turns out to be less than 3.8 Jupiter masses.

Name: Sagittarius, SWEEPS
Type: Milky Way : Star : Grouping : MultipleMilky Way : Star : Circumstellar Material : Planetary System
Category: Exoplanets
Distance: 25000 light years
Release date: 4 October 2006, 19:00
Credit: NASA, ESA, K. Sahu (STScI) and the SWEEPS science team