The Hubble Space Telescope has imaged the star field around the Cepheid variable V1 in M31. This two-color image shows individually resolved stars in the outer disk of the Andromeda Galaxy. The soft, brown swirls are dust lanes obscuring light from stars farther away from our line of sight. The blue cluster towards the upper right of the image contains massive young stars that are emanating intense ultraviolet light. The Cepheid variable, V1, the first Cepheid ever found outside of our own galaxy, is a moderate-looking star in the lower left of the image.

Object Name: M31-V1

Image Type: Astronomical

Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

Time And Space


Faintest Galaxies Ever Seen Explain The ‘Missing Link’ In The Universe

“By warping space, the light from background objects gets magnified, revealing extraordinarily faint galaxies. The only problem? The cluster itself is closer and overwhelmingly luminous, making it impossible to tease out the distant signals. Until now. Thanks to a superior new technique devised by Rachael Livermore, light from the foreground cluster galaxies can be modeled and subtracted, revealing faint, distant galaxies never seen before.”

One of the biggest puzzles in science is exactly how the Universe became transparent to visible light. Neutral atoms – cosmic dust – blocks visible light, and yet before there were stars, that’s all we had. According to theory, it should be large numbers of small, faint, ultra-distant galaxies that made it transparent, but they’ve never been seen. However, thanks to the combined power of the Hubble Space Telescope, gravitational lensing and a new foreground light-removal technique, galaxies 100 times fainter thank the ones visible in the Hubble eXtreme Deep Field – the longest-exposure image ever – have now been revealed. These galaxies, seen in two Frontier Fields’ clusters so far, are the ‘missing link’ needed to explain reionization.

Come get the full, stunning story in visuals and no more than 200 words on today’s Mostly Mute Monday!


ripples: Crab Nebula, photographed by Hubble, autumn 2005.

10 images in 558 nm (green) light, September-December 2005.

The Crab Nebula is a cloud of gas 11 light years across, created by the collapse and explosion of a giant star in 1054 AD (a Type II supernova). At the centre of the nebula is a neutron star, the Crab Pulsar, the incredibly dense remnant of the original star; 1.5 to 2 times the mass of the Sun, but only 30 km across. Intense solar wind from the pulsar creates visible ripples in the surrounding nebula.

From Proposal 10526. Some more gifs of the Crab Nebula seen by Hubble.

Image credit: NASA/ESA/STScI. Animation: AgeOfDestruction.

Near the outskirts of the Small Magellanic Cloud, lies 5 million year old star cluster, NGC 602. Surrounded by gas and dust, NGC 602 is featured in this stunning optical Hubble image of the region, is a combination of images in the X-ray by Chandra, and in the infrared by Spitzer. Fantastic ridges and swept back shapes strongly suggest that energetic radiation and shock waves from NGC 602’s massive young stars have eroded the dusty material and triggered a progression of star formation moving away from the cluster’s center. The background galaxies are hundreds of millions of light-years or more beyond NGC 602.

Image Credit: X-ray: Chandra: NASA/CXC/Univ.Potsdam/L.Oskinova et al;
Optical: Hubble: NASA/STScI; Infrared: Spitzer: NASA/JPL-Caltech 

Resembling festive lights on a holiday wreath, this NASA/ESA Hubble Space Telescope image of the nearby spiral galaxy M74 is an iconic reminder of the impending season. Bright knots of glowing gas light up the spiral arms, indicating a rich environment of star formation.

Messier 74, also called NGC 628, is a stunning example of a “grand-design” spiral galaxy that is viewed by Earth observers nearly face-on. Its perfectly symmetrical spiral arms emanate from the central nucleus and are dotted with clusters of young blue stars and glowing pink regions of ionized hydrogen (hydrogen atoms that have lost their electrons). These regions of star formation show an excess of light at ultraviolet wavelengths. Tracing along the spiral arms are winding dust lanes that also begin very near the galaxy’s nucleus and follow along the length of the spiral arms.

M74 is located roughly 32 million light-years away in the direction of the constellation Pisces, the Fish. It is the dominant member of a small group of about half a dozen galaxies, the M74 galaxy group. In its entirety, it is estimated that M74 is home to about 100 billion stars, making it slightly smaller than our Milky Way.

The spiral galaxy was first discovered by the French astronomer Pierre Méchain in 1780. Weeks later it was added to Charles Messier’s famous catalog of deep-sky objects.

This Hubble image of M74 is a composite of Advanced Camera for Surveys data taken in 2003 and 2005. The filters used to create the color image isolate light from blue, visible, and infrared portions of the spectrum, as well as emission from ionized hydrogen (known as HII regions).

A small segment of this image used data from the Canada-France-Hawaii Telescope and the Gemini Observatory to fill in a region that Hubble did not image.

For additional information, contact:

Ray Villard
Space Telescope Science Institute, Baltimore, Md.

Keith Noll
Space Telescope Science Institute, Baltimore, Md.

Lars Lindberg Christensen
ESA/Hubble, Garching, Germany

Object Names: M74, NGC 628

Image Type: Astronomical

Credit: NASA, ESA, and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration

Acknowledgment: R. Chandar (University of Toledo) and J. Miller (University of Michigan)

Time And Space

Cygnus A

The galaxy Cygnus A, which played a prominent role in Carl Sagan’s 1985 novel “Contact,” is shown here in multiple wavelengths, including X-ray, radio and visible. A new study looks at the powerful magnetic fields produced by jets spewing out of the monster black hole at the galaxy’s center.

Credit: NASA / STScI

This delicate shell, photographed by the NASA/ESA Hubble Space Telescope, appears to float serenely in the depths of space, but this apparent calm hides an inner turmoil. The gaseous envelope formed as the expanding blast wave and ejected material from a supernova tore through the nearby interstellar medium. Called SNR B0509-67.5 (or SNR 0509 for short), the bubble is the visible remnant of a powerful stellar explosion in the Large Magellanic Cloud (LMC), a small galaxy about 160 000 light-years from Earth. Ripples in the shell’s surface may be caused either by subtle variations in the density of the ambient interstellar gas, or possibly be driven from the interior by fragments from the initial explosion. The bubble-shaped shroud of gas is 23 light-years across and is expanding at more than 18 million km/h.

Hubble’s Advanced Camera for Surveys observed the supernova remnant on 28 October 2006 with a filter that isolates light from the glowing hydrogen seen in the expanding shell. These observations were then combined with visible-light images of the surrounding star field that were imaged with Hubble’s Wide Field Camera 3 on 4 November 2010.


NASA, ESA, and the Hubble Heritage Team (STScI/AURA). Acknowledgement: J. Hughes (Rutgers University)

New images from NASA’s Hubble Space Telescope are helping researchers view in unprecedented detail the spiral arms and dust clouds of a nearby galaxy, which are the birth sites of massive and luminous stars.

The Whirlpool galaxy, M51, has been one of the most photogenic galaxies in amateur and professional astronomy. Easily photographed and viewed by smaller telescopes, this celestial beauty is studied extensively in a range of wavelengths by large ground- and space-based observatories. This Hubble composite image shows visible starlight as well as light from the emission of glowing hydrogen, which is associated with the most luminous young stars in the spiral arms.

M51, also known as NGC 5194, is having a close encounter with a nearby companion galaxy, NGC 5195, just off the upper edge of this image. The companion’s gravitational pull is triggering star formation in the main galaxy, as seen in brilliant detail by numerous, luminous clusters of young and energetic stars. The bright clusters are highlighted in red by their associated emission from glowing hydrogen gas.

This Wide Field Planetary Camera 2 image enables a research group, led by Nick Scoville (Caltech), to clearly define the structure of both the cold dust clouds and the hot hydrogen and link individual clusters to their parent dust clouds. Team members include M. Polletta (U. Geneva); S. Ewald and S. Stolovy (Caltech); R. Thompson and M. Rieke (U. of Arizona).

Intricate structure is also seen for the first time in the dust clouds. Along the spiral arms, dust “spurs” are seen branching out almost perpendicular to the main spiral arms. The regularity and large number of these features suggests to astronomers that previous models of “two-arm” spiral galaxies may need to be revisited. The new images also reveal a dust disk in the nucleus, which may provide fuel for a nuclear black hole.

The team is also studying this galaxy at near-infrared wavelengths with the NICMOS instrument onboard Hubble. At these wavelengths, the dusty clouds are more transparent and the true distribution of stars is more easily seen. In addition, regions of star formation that are obscured in the optical images are newly revealed in the near-infrared images.

This image was composed by the Hubble Heritage Team from Hubble archival data of M51 and is superimposed onto ground-based data taken by Travis Rector (NOAO) at the 0.9-meter telescope at the National Science Foundation’s Kitt Peak National Observatory (NOAO/AURA) in Tucson, AZ.

Object Names: The Whirlpool Galaxy, M51

Image Type: Astronomical

Image Credit: NASA and The Hubble Heritage Team (STScI/AURA)

Acknowledgment: N. Scoville (Caltech) and T. Rector (NOAO)

Time And Space

Stellar spire in the Eagle Nebula

Appearing like a winged fairy-tale creature poised on a pedestal, this object is actually a billowing tower of cold gas and dust rising from a stellar nursery called the Eagle Nebula. The soaring tower is 9.5 light-years or about 90 trillion kilometres high, about twice the distance from our Sun to the next nearest star. Credit: NASA, ESA, and The Hubble Heritage Team STScI/AURA)

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.

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.

Object Name: NGC 3603

Image Type: Astronomical

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)

Time And Space


New Insights Into the Crab Nebula

Five observatories teamed up to spy on the Crab Nebula and the results are incredible. The VLA (radio) views are shown in red; Spitzer Space Telescope (infrared) in yellow; Hubble Space Telescope (visible) in green; XMM-Newton (ultraviolet) in blue; and Chandra X-ray Observatory (X-ray) in purple.

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