This picture shows NGC 5398, a barred spiral galaxy located about 55 million light-years away.
The galaxy is famous for containing an especially extensive HII region, a large cloud composed of ionized hydrogen (or HII, pronounced “H-two,” with H being the chemical symbol for hydrogen and the “II” indicating that the atoms have lost an electron to become ionized). NGC 5398’s cloud is named Tol 89 and sits at the lower left end of the galaxy’s central “bar” of stars, a structure that cuts through the galactic core and funnels material inwards to maintain the star formation occurring there.
Tol 86 is conspicuous in being the only large massive star-forming complex in the entire galaxy, with an extension of roughly 5,000 times it contains at least seven young and massive star clusters. The two brightest clumps within Tol 89, which astronomers have named simply “A” and “B” appear to have undergone two bursts of star-forming activity — “starbursts” — roughly 4 million and less than 3 million years ago respectively. Tol 89-A is thought to contain a number of particularly bright and massive stars known as Wolf-Rayet stars, which are known for their high temperatures and extreme stellar winds.
In this artist's depiction, Hubble has observed a planet outside our solar system that looks as black as fresh asphalt because it eats light rather than reflecting it back into space. This light-eating prowess is due to the planet's unique capability to trap at least 94 percent of the visible starlight falling into its atmosphere.
The oddball exoplanet, called WASP-12b, is one of a class of so-called "hot Jupiters," gigantic, gaseous planets that orbit very close to their host star and are heated to extreme temperatures. The planet's atmosphere is so hot that most molecules are unable to survive on the blistering day side of the planet, where the temperature is 4,600 degrees Fahrenheit. Therefore, clouds probably cannot form to reflect light back into space. Instead, incoming light penetrates deep into the planet's atmosphere where it is absorbed by hydrogen atoms and converted to heat energy.
But the planet's nighttime side is a different story. WASP-12b has a fixed day side and night side because it orbits so close to the star that it is tidally locked. The nighttime side is more than 2,000 degrees Fahrenheit cooler, which allows water vapor and clouds to form. Previous Hubble observations of the day/night boundary detected evidence of water vapor and possibly clouds and hazes in the atmosphere. WASP-12b is about 2 million miles away from its star and completes an orbit once a day.
The researchers determined the planet's light-eating capabilities by using Hubble's Space Telescope Imaging Spectrograph to search in mostly visible light for a tiny dip in starlight as the planet passed directly behind the star. The amount of dimming tells astronomers how much reflected light is given off by the planet. However, the observations did not detect reflected light, meaning that the daytime side of the planet is absorbing almost all the starlight falling onto it.
Congratulations on 20 years of exploration, Cassini! A big thanks from Hubble for your investigation into Saturn and its moons. #GrandFinale
Saturn is famous for the intriguing rings that encircle it. As Saturn orbits the Sun, though, our view of its rings changes. Roughly every 15 years (halfway through Saturn’s almost-30-year orbit), Saturn’s rings appear edge-on, sometimes seeming to disappear altogether. Because many of Saturn’s moons orbit the planet in the same plane as the rings, they appear to cross in front of the planet during this time.
On February 24, 2009, when Saturn’s rings were nearly edge-on, Hubble tracked four of Saturn’s moons as they passed across the face of the giant ringed planet. In this image, captured with Hubble’s Wide Field Planetary Camera 2, Saturn’s large, orangish moon Titan casts a deep, round shadow near the upper edge of Saturn’s disk. The smaller moon Mimas and its shadow appear as white and black dots to the lower left of Titan, just above the long, thin shadow projected onto Saturn by the planet’s rings. Bright Dione and the fainter Enceladus hover above the rings on the far left.
#HubbleFriday : Like firecrackers lighting up the sky on New Year’s Eve, the majestic spiral arms of NGC 5559 are alight with new stars being born. NGC 5559 is a spiral galaxy, with spiral arms filled with gas and dust sweeping out around the bright galactic bulge. These arms are a rich environment for star formation, dotted with a festive array of colors including the newborn stars glowing blue as a result of their immensely high temperatures.
NGC 5559 was discovered by astronomer William Herschel in 1785 and lies approximately 240 million light-years away in the northern constellation of Boötes (the herdsman)
In 2001, a calcium-rich supernova called 2001co was observed in NGC 5559. Calcium-rich supernovae are described as “fast-and-faint,” as they're less luminous than other types of supernovae and also evolve more rapidly, to reveal spectra dominated by strong calcium lines. 2001co occurred within the disk of NGC 5559 near star-forming regions, but calcium-rich supernovae are often observed at large distances from the nearest galaxy, raising curious questions about their progenitors.
#ThrowbackThursday : In this image, Swiss astronaut Claude Nicollier is pictured at the aft flight deck station he occupied during much of the time on NASA's STS-61 mission aboard Space Shuttle Endeavour. This was during the first servicing mission, but Claude would return to Hubble again in December of 1999 for Servicing Mission 3A.
Also, a happy belated birthday to him, as his birthday was this past Saturday! 🎉
Phenomena across the Universe emit radiation spanning the entire electromagnetic spectrum — from high-energy gamma rays, which stream out from the most energetic events in the cosmos, to lower-energy microwaves and radio waves.
Microwaves, the very same radiation that can heat up your dinner, are produced by a multitude of astrophysical sources, including strong emitters known as masers (microwave lasers), even stronger emitters with the somewhat villainous name of megamasers and the centers of some galaxies. Especially intense and luminous galactic centers are known as active galactic nuclei. They are in turn thought to be driven by the presence of supermassive black holes, which drag surrounding material inwards and spit out bright jets and radiation as they do so.
The two galaxies shown here, imaged by the NASA/ESA Hubble Space Telescope, are named MCG+01-38-004 (the upper, red-tinted one) and MCG+01-38-005 (the lower, blue-tinted one). MCG+01-38-005 (also known as NGC 5765B) is a special kind of megamaser the galaxy’s active galactic nucleus pumps out huge amounts of energy, which stimulates clouds of surrounding water. Water’s constituent atoms of hydrogen and oxygen are able to absorb some of this energy and re-emit it at specific wavelengths, one of which falls within the microwave regime, invisible to Hubble but detectable by microwave telescopes. MCG+01-38-005 is thus known as a water megamaser!
Astronomers can use such objects to probe the fundamental properties of the Universe. The microwave emissions from MCG+01-38-005 were used to calculate a refined value for the Hubble constant, a measure of how fast the Universe is expanding. This constant is named after the astronomer whose observations were responsible for the discovery of the expanding Universe and after whom the Hubble Space Telescope was named, Edwin Hubble.
The bright clusters and nebulas of planet Earth's night sky are often named for flowers or insects. Though its wingspan covers over 3 light-years, NGC 6302 is no exception. With an estimated surface temperature of about 250,000 degrees Celsius, the dying central star of this particular planetary nebula has become exceptionally hot, shining brightly in ultraviolet light but hidden from direct view by a dense torus of dust.
This sharp and colorful close-up of the dying star's nebula was recorded in 2009 by the Hubble Space Telescope's Wide Field Camera 3, installed during the final shuttle servicing mission. Cutting across a bright cavity of ionized gas, the dust torus surrounding the central star is near the center of this view, almost edge-on to the line-of-sight. Molecular hydrogen has been detected in the hot star's dusty cosmic shroud. NGC 6302 lies about 4,000 light-years away in the arachnologically correct constellation of the Scorpion (Scorpius). Credit: NASA/Hubble #Hubble#space#science#astronomy#nebula#butterfly
This Hubble image shows a pair of interacting galaxies collectively known as Arp 273. The larger of the spiral galaxies, known as UGC 1810, has a disk that is distorted into a rose-like shape by the gravitational tidal pull of the companion galaxy below it, known as UGC 1813. This image is a composite of data taken on December 17, 2010, with three separate filters that allow a broad range of wavelengths covering the ultraviolet, blue, and red portions of the spectrum.
Credit: NASA/Hubble #Hubble#space#science#astronomy#galaxy#star#rose
What caused this outburst of V838 Monocerotis? For reasons unknown, star V838 Mon's outer surface suddenly expanded causing it to become the brightest star in the entire Milky Way galaxy in January 2002. Then, just as suddenly, it faded. A stellar flash like this had never been seen before — supernovas and novas expel matter out into space. Although the V838 Mon flash appears to expel material into space, what is seen in the image from Hubble is actually an outwardly moving light echo of the bright flash.
In a light echo, light from the flash is reflected by successively more distant rings in the complex array of ambient interstellar dust that already surrounded the star. V838 Mon lies about 20,000 light-years away toward the constellation of the unicorn (Monoceros), while the light echo here spans about six light-years in diameter.
Credit: NASA/Hubble #Hubble#space#science#astronomy#star
Called the Hubble Ultra Deep Field (HUDF), this million-second-long exposure reveals the first galaxies to emerge from the so-called "dark ages," the time shortly after the big bang when the first stars reheated the cold, dark universe. This image offered new insights into what types of objects reheated the universe long ago.
This historic new view is actually two separate images taken by Hubble's Advanced Camera for Surveys (ACS) and the Near Infrared Camera and Multi-Object Spectrometer (NICMOS). Both images reveal galaxies that are too faint to be seen by ground-based telescopes, or even in Hubble's previous faraway looks, called the Hubble Deep Fields (HDFs), taken in 1995 and 1998.
Credit: NASA/Hubble #Hubble#space#science#astronomy#galaxy#star
From the dawn of humankind to a mere 400 years ago, all that we knew about our universe came through observations with the naked eye. Then Galileo turned his telescope toward the heavens in 1610. The world was in for an awakening.
Saturn, we learned, had rings. Jupiter had moons. That nebulous patch across the center of the sky called the Milky Way was not a cloud but a collection of countless stars. Within but a few years, our notion of the natural world would be forever changed. A scientific and societal revolution quickly ensued.
In the centuries that followed, telescopes grew in size and complexity and, of course, power. They were placed far from city lights and as far above the haze of the atmosphere as possible. Edwin Hubble, for whom the Hubble Telescope is named, used the largest telescope of his day in the 1920s at the Mt. Wilson Observatory near Pasadena, California, to discover galaxies beyond our own.
Hubble, the observatory, is the first major optical telescope to be placed in space, the ultimate mountaintop. Above the distortion of the atmosphere, far above rain clouds and light pollution, Hubble has an unobstructed view of the universe. Scientists have used Hubble to observe the most distant stars and galaxies as well as the planets in our solar system.
Hubble's launch and deployment in April 1990 marked the most significant advance in astronomy since Galileo's telescope. Thanks to five servicing missions and more than 25 years of operation, our view of the universe and our place within it has never been the same.
Credit: NASA/Hubble #Hubble#space#science#astronomy#galaxy#star#nebula
This crisp image of the Orion Nebula reveals a tapestry of star formation, from the dense pillars of gas and dust that may be the homes of fledgling stars to the hot, young, massive stars that have emerged from their gas-and-dust cocoons and are shaping the nebula with their powerful ultraviolet light.
In a mosaic containing a billion pixels, Hubble's Advanced Camera for Surveys (ACS) uncovered 3,000 stars of various sizes. Some of them have never been spied in visible light. Some are merely 1/100th the brightness of stars seen previously in the nebula.
Credit: NASA/Hubble #Hubble#space#science#astronomy#nebula