In the center of this image, taken with the NASA/ESA Hubble Space Telescope, is the galaxy cluster SDSS J1038+4849 — and it seems to be
You can make out its two orange eyes and white button nose. In the
case of this “happy face”, the two eyes are very bright galaxies and the
misleading smile lines are actually arcs caused by an effect known as
strong gravitational lensing.
Galaxy clusters are the most massive structures in the Universe and
exert such a powerful gravitational pull that they warp the spacetime
around them and act as cosmic lenses which can magnify, distort and bend
the light behind them. This phenomenon, crucial to many of Hubble’s
discoveries, can be explained by Einstein’s theory of general
In this special case of gravitational lensing, a ring — known as an
Einstein Ring — is produced from this bending of light, a consequence of
the exact and symmetrical alignment of the source, lens and observer
and resulting in the ring-like structure we see here.
Hubble has provided astronomers with the tools to probe these massive
galaxies and model their lensing effects, allowing us to peer further
into the early Universe than ever before. This object was studied by
Hubble’s Wide Field and Planetary Camera 2 (WFPC2) and Wide Field Camera
3 (WFC3) as part of a survey of strong lenses.
A version of this image was entered into the Hubble’s Hidden Treasures image processing competition by contestant Judy Schmidt.
NASA’s Hubble Space Telescope captured this billowing cloud of cold interstellar gas and dust rising from a tempestuous stellar nursery located in the Carina Nebula, 7,500 light-years away in the southern constellation Carina. This pillar of dust and gas serves as an incubator for new stars and is teeming with new star-forming activity.
Hot, young stars erode and sculpt the clouds into this fantasy landscape by sending out thick stellar winds and scorching ultraviolet radiation. The low- density regions of the nebula are shredded while the denser parts resist erosion and remain as thick pillars. In the dark, cold interiors of these columns new stars continue to form.
In the process of star formation, a disk around the proto-star slowly accretes onto the star’s surface. Part of the material is ejected along jets perpendicular to the accretion disk. The jets have speeds of several hundreds of miles per second. As these jets plow into the surround nebula, they create small, glowing patches of nebulosity, called Herbig-Haro (HH) objects.
Long streamers of gas can be seen shooting in opposite directions off the pedestal on the upper right-hand side of the image. Another pair of jets is visible in a peak near the top-center of the image. These jets (known as HH 901 and HH 902, respectively) are common signatures of the births of new stars.
This image celebrates the 20th anniversary of Hubble’s launch and deployment into an orbit around Earth. Hubble’s Wide Field Camera 3 observed the pillar on Feb. 1-2, 2010. The colors in this composite image correspond to the glow of oxygen (blue), hydrogen and nitrogen (green), and sulfur (red).
Credit: NASA, ESA, and M. Livio and the Hubble 20th Anniversary Team (STScI)
The spectacular new camera installed on NASA’s Hubble Space Telescope during Servicing Mission 4 in May has delivered the most detailed view of star birth in the graceful, curving arms of the nearby spiral galaxy M83.
Nicknamed the Southern Pinwheel, M83 is undergoing more rapid star formation than our own Milky Way galaxy, especially in its nucleus. The sharp “eye” of the Wide Field Camera 3 (WFC3) has captured hundreds of young star clusters, ancient swarms of globular star clusters, and hundreds of thousands of individual stars, mostly blue supergiants and red supergiants. The image at right, taken in August 2009, is Hubble’s close-up view of the myriad stars near the galaxy’s core, the bright whitish region at far right. An image of the entire galaxy, taken by the European Southern Observatory’s Wide Field Imager on the ESO/MPG 2.2-meter telescope at La Silla, Chile, is shown at left. The white box outlines Hubble’s view.
Un atlante di nebulose planetarie galattiche che assembla immagini ottenute con la WFC3 del telescopio spaziale Hubble. Di ogni oggetto sono presenti immagini in quattro diversi filtri e ogni immagine copre un'area di 5x5 secondi d'arco, corrispondenti a un quadrato di 127 pixel di lato sulla WFC3.
This week I’ve been looking at adding something called CTE correction into our data reduction pipeline. Charge transfer efficiency (CTE) on CCDs, at least in space, degrades over time, due to impacts by high energy particles. Photons generate electrons when they impinge on the CCD, and, to read the electron counts, the electrons are sequentially shifted down their row of pixels. But slight defects in a pixel can wind up trapping a few of them, resulting in artificially decreased pixel values.
The effect’s pretty slight, but folks here have figured out how to correct for it, at least on a few of Hubble’s instruments. The problem is that CTE correction is most important to scientists doing exacting aperture photometry on point sources, like stars. It was not developed for extended objects, like planets, in mind.
Our pipeline’s all about planets. So I took a look at what CTE correction does to this image of Europa transiting in front of Jupiter, taken by Hubble’s WFC3 instrument. The purple image is the difference between the original image and the CTE corrected image. Unfortunately, the correction routine appears to interpret the limb of the planet as CTE errors. Towards the bottom of the register, it brightens Jupiter’s limb, and towards the top of the register, it darkens it.
So we’re probably not going to be using CTE correction. Also, it is really computationally expensive. Processing this image took about an hour, and we’ve got much larger ones. But it was rather cool to look at.
Also, I think the difference image is quite pretty. I swear I picked that particular color map because it well-displays different extremes in the pixel difference, not because it made everything all purple and orange. But still.
Like a July 4 fireworks display, a young, glittering collection of stars looks like an aerial burst. The cluster is surrounded by clouds of interstellar gas and dust – the raw material for new star formation. The nebula, located 20,000 light-years away in the constellation Carina, contains a central cluster of huge, hot stars, called NGC 3603.
This environment is not as peaceful as it looks. Ultraviolet radiation and violent stellar winds have blown out an enormous cavity in the gas and dust enveloping the cluster, providing an unobstructed view of the cluster.
Most of the stars in the cluster were born around the same time but differ in size, mass, temperature, and color. The course of a star’s life is determined by its mass, so a cluster of a given age will contain stars in various stages of their lives, giving an opportunity for detailed analyses of stellar life cycles. NGC 3603 also contains some of the most massive stars known. These huge stars live fast and die young, burning through their hydrogen fuel quickly and ultimately ending their lives in supernova explosions.
Astronomers believe most stars – including stars like the Sun – are born in clusters. Star clusters like NGC 3603 provide important clues to understanding the origin of massive star formation in the early, distant universe. Astronomers also use massive clusters to study distant starbursts that occur when galaxies collide, igniting a flurry of star formation. The proximity of NGC 3603 makes it an excellent lab for studying such distant and momentous events.
This Hubble Space Telescope image was captured in August 2009 and December 2009 with the Wide Field Camera 3 in both visible and infrared light, which trace the glow of sulfur, hydrogen, and iron.
Credit: NASA, ESA, R. O'Connell (University of Virginia), F. Paresce (National Institute for Astrophysics, Bologna, Italy), E. Young (Universities Space Research Association/Ames Research Center), the WFC3 Science Oversight Committee, and the Hubble Heritage Team (STScI/AURA)
A clash among members of a famous galaxy quintet reveals an assortment of stars across a wide colour range, from young, blue stars to aging, red stars.
This portrait of Stephan’s Quintet, also known as the Hickson Compact Group 92, was taken by the new Wide Field Camera 3 (WFC3) aboard the NASA/ESA Hubble Space Telescope. Stephan’s Quintet, as the name implies, is a group of five galaxies. The name, however, is a bit of a misnomer. Studies have shown that group member NGC 7320, at upper left, is actually a foreground galaxy that is about seven times closer to Earth than the rest of the group.
Three of the galaxies have distorted shapes, elongated spiral arms, and long, gaseous tidal tails containing myriad star clusters, proof of their close encounters. These interactions have sparked a frenzy of star birth in the central pair of galaxies. This drama is being played out against a rich backdrop of faraway galaxies.
The image, taken in visible and near-infrared light, showcases WFC3’s broad wavelength range. The colours trace the ages of the stellar populations, showing that star birth occurred at different epochs, stretching over hundreds of millions of years. The camera’s infrared vision also peers through curtains of dust to see groupings of stars that cannot be seen in visible light.
NGC 7319, at top right, is a barred spiral with distinct spiral arms that follow nearly 180 degrees back to the bar. The blue specks in the spiral arm at the top of NGC 7319 and the red dots just above and to the right of the core are clusters of many thousands of stars. Most of the Quintet is too far away even for Hubble to resolve individual stars.
Continuing clockwise, the next galaxy appears to have two cores, but it is actually two galaxies, NGC 7318A and NGC 7318B. Encircling the galaxies are young, bright blue star clusters and pinkish clouds of glowing hydrogen where infant stars are being born. These stars are less than 10 million years old and have not yet blown away their natal cloud. Far away from the galaxies, at right, is a patch of intergalactic space where many star clusters are forming.
NGC 7317, at bottom left, is a normal-looking elliptical galaxy that is less affected by the interactions.
Sharply contrasting with these galaxies is the dwarf galaxy NGC 7320 at upper left. Bursts of star formation are occurring in the galaxy’s disc, as seen by the blue and pink dots. In this galaxy, Hubble can resolve individual stars, evidence that NGC 7320 is closer to Earth. NGC 7320 is 40 million light-years from Earth. The other members of the Quintet reside about 300 million light-years away in the constellation Pegasus.
These more distant members are markedly redder than the foreground galaxy, suggesting that older stars reside in their cores. The stars’ light also may be further reddened by dust stirred up in the encounters.
Spied by Edouard M. Stephan in 1877, Stephan’s Quintet is the first compact group ever discovered.
WFC3 observed the Quintet in July and August 2009. The composite image was made by using filters that isolate light from the blue, green and infrared portions of the spectrum, as well as emission from ionised hydrogen.
These Hubble observations are part of the Hubble Servicing Mission 4 Early Release Observations. NASA astronauts installed the WFC3 camera during a servicing mission in May to upgrade and repair the 19-year-old Hubble telescope.