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Hubble Image of He2-90
This mysterious object that
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8/31/00
| Date |
8/31/00 |
| Description |
This mysterious object that seems to defy classification was found by astronomers using NASA's Hubble Space Telescope. The object has been classified as a planetary nebula, the glowing remains of a Sun-like star in its death throes, although the Hubble observations suggest it may not fit that classification, either. A quick glance at the Hubble picture at top shows that the object, He2-90, looks like a young, dust-enshrouded star with narrow jets of material resembling strings of beads streaming from each side. The other light streaks running diagonally from He2-90 are artificial effects of the telescope's optical system. Each jet possesses at least six bright clumps of gas speeding along at rates estimated to be at least 600,000 kilometers an hour (375,000 miles an hour). These gaseous clumps are ejected into space about every 100 years and may be caused by periodic instabilities in He2-90's accretion disk. Jets from very young stars behave in a similar way. Deep images taken from a terrestrial observatory show each jet extending at least 100,000 astronomical units (one astronomical unit equals the Earth-Sun distance, 150 million kilometers or 93 million miles). The Hubble astronomers, Dr. Raghvendra Sahai of NASA's Jet Propulsion Laboratory, Pasadena, Calif., and Lars-Ake Nyman of the European Southern Observatory, Chile, and Onsala Space Observatory, Sweden, suspect that He2-9 is a pair of aging stars masquerading as a single youngster. One member of the duo is a bloated red giant star shedding matter from its outer layers. This matter is then captured by gravity in a rotating accretion disk around a compact partner, most likely a young white dwarf (the collapsed remnant of a Sun-like star). The stars are not visible in the Hubble images because they're obscured by a disk of dust. The jets' relatively modest speed implies that one member of the duo is a white dwarf. An accretion disk needs gravity to form. For gravity to create He2-90's disk, the two stars must reside at a cozy distance from each other: within about 10 astronomical units. Astronomers are uncertain about the details, but they believe that magnetic fields associated with accretion disks produce and constrict the pencil-thin jets seen in the Hubble image. The close-up Hubble photo at bottom shows a dark, flaring, disk-like structure (off-center) bisecting the bright light from the object. The disk is seen edge-on. Although this disk is too large to be an accretion disk, it may provide indirect proof of the disk's existence. Most theories for producing jets require the presence of an accretion disk. The round, white objects at the lower left and upper right corners are two bright clumps of gas in the jets, which are close to the companion star. The astronomers traced the jets to within 1,000 astronomical units of the central obscured star. The star ejected this material about 30 years ago. This oddball star was discovered during an imaging survey of planetary nebulae. The images were taken Sept. 28, 1999 with Hubble's Wide Field and Planetary Camera 2. The images and results appear in the Aug. 1 issue of the Astrophysical Journal Letters. JPL designed and built the Wide Field and Planetary Camera 2. The Space Telescope Science Institute, Baltimore, Md, manages space operations for the Hubble Space Telescope for NASA's Office of Space Science, Washington, D.C. The Institute is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract with NASA's Goddard Space Flight Center, Greenbelt, Md. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. ##### |
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Embryonic Stars Emerge from
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| Title |
Embryonic Stars Emerge from Interstellar "Eggs |
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Embryonic Stars Emerge from
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| Title |
Embryonic Stars Emerge from Interstellar "Eggs |
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Embryonic Stars Emerge from
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| Title |
Embryonic Stars Emerge from Interstellar "Eggs |
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Hubble Provides the First Im
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| Title |
Hubble Provides the First Images of Saturn's Aurorae |
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Hubble's Deepest View of the
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| Title |
Hubble's Deepest View of the Universe Unveils Bewildering Galaxies across Billions of Years |
| General Information |
What is an American Astronomical Society Meeting release? A major news announcement issued at an American Astronomical Society meeting, the premier astronomy conference. One peek into a small part of the sky, one giant leap back in time. The Hubble telescope has provided mankind's deepest, most detailed visible view of the universe. Representing a narrow "keyhole" view stretching to the visible horizon of the universe, the Hubble Deep Field image covers a speck of the sky only about the width of a dime 75 feet away. Though the field is a very small sample of the heavens, it is considered representative of the typical distribution of galaxies in space, because the universe, statistically, looks largely the same in all directions. Gazing into this small field, Hubble uncovered a bewildering assortment of at least 1,500galaxies at various stages of evolution. Read more: * Release Text [ http://hubblesite.org/newscenter/archive/releases/1996/01/text/ ] |
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Hubble Monitors Weather on N
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Hubble Monitors Weather on Neighboring Planets |
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Hubble Finds Thousands of Ga
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| Title |
Hubble Finds Thousands of Gaseous Fragments Surrounding a Dying Star |
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Hubble Space Telescope Obser
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Hubble Space Telescope Observations of Neptune |
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Doomed Star Eta Carinae
| Title |
Doomed Star Eta Carinae |
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Hubble Discovers New Dark Sp
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| Title |
Hubble Discovers New Dark Spot on Neptune |
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Hubble Captures the Heart of
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| Title |
Hubble Captures the Heart of Star Birth |
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Doomed Star Eta Carinae
| Title |
Doomed Star Eta Carinae |
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Looking Down a Barrel of Gas
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| Title |
Looking Down a Barrel of Gas at a Doomed Star |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Astronomers using the Hubble telescope have obtained the sharpest view yet of a glowing loop of gas called the Ring Nebula (M57), first cataloged more than 200 years ago by French astronomer Charles Messier. The pictures reveal that the "Ring" is actually a cylinder of gas seen almost end-on. Such elongated shapes are common among other planetary nebulae, because thick disks of gas and dust form a waist around a dying star. This "waist" slows down the expansion of material ejected by the doomed object. The easiest escape route for this cast-off material is above and below the star. This photo reveals dark, elongated clumps of material embedded in the gas at the edge of the nebula, the dying central star is floating in a blue haze of hot gas. Read more: * Release Text [ http://hubblesite.org/newscenter/archive/releases/1999/01/text/ ] |
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A Mote in Hubble's Eye
| Title |
A Mote in Hubble's Eye |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. The Hubble telescope image is a typical Milky Way star field in the constellation Centaurus. Such snapshots can be used to study the evolution of stars that make up our galaxy. Most of the stars in this image lie near the center of our galaxy some 25,000 light-years distant. But one object, the blue curved streak [top right], is something much closer. An uncatalogued, mile-wide bit of rocky debris ? an asteroid ? orbiting the Sun only light-minutes away strayed into Hubble's field of view. An analysis of this asteroid indicates this asteroid's orbit could cross Mars's path. |
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Hubble Telescope Reveals Swa
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| Title |
Hubble Telescope Reveals Swarm of Glittering Stars in Nearby Galaxy |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Back to top [ #top ] |
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Light and Shadow in the Cari
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| Title |
Light and Shadow in the Carina Nebula |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Back to top [ #top ] |
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Fireworks of Star Formation
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| Title |
Fireworks of Star Formation Light up a Galaxy |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Back to top [ #top ] |
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Hubble Reopens Its Eye on th
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| Title |
Hubble Reopens Its Eye on the Universe |
| General Information |
What is an Early Release Observation? A photograph of a celestial object that demonstrates the performance of a new Hubble camera. Back to top [ #top ] |
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Hubble Reopens Its Eye on th
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| Title |
Hubble Reopens Its Eye on the Universe |
| General Information |
What is an Early Release Observation? A photograph of a celestial object that demonstrates the performance of a new Hubble camera. Back to top [ #top ] |
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A Dying Star in Globular Clu
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| Title |
A Dying Star in Globular Cluster M15 |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Back to top [ #top ] |
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Feasting Black Hole Blows Bu
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| Title |
Feasting Black Hole Blows Bubbles |
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Movies from Hubble Show the
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| Title |
Movies from Hubble Show the Changing Faces of Infant Stars |
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SN1987A in the Large Magella
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| Title |
SN1987A in the Large Magellanic Cloud |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Glittering stars and wisps of gas create a breathtaking backdrop for the self-destruction of a massive star, called supernova 1987A, in the Large Magellanic Cloud, a nearby galaxy. Astronomers in the Southern Hemisphere witnessed the brilliant explosion of this star on Feb. 23, 1987. Shown in this Hubble telescope image, the supernova remnant, surrounded by inner and outer rings of material, is set in a forest of ethereal, diffuse clouds of gas. |
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Hubble Captures an Extraordi
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| Title |
Hubble Captures an Extraordinary and Powerful Active Galaxy |
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X" Marks the Spot: Hubble Se
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| Title |
X" Marks the Spot: Hubble Sees the Glow of Star Formation in a Neighbor Galaxy |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Back to top [ #top ] |
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Hubble Spies Huge Clusters o
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| Title |
Hubble Spies Huge Clusters of Stars Formed by Ancient Encounter |
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Internet Voters Get Two Gala
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| Title |
Internet Voters Get Two Galaxies in One from Hubble |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Located about 130 million light-years away, NGC 4650A is one of only 100 known polar-ring galaxies. Their unusual disk-ring structure is not yet understood fully. One possibility is that polar rings are the remnants of colossal collisions between two galaxies sometime in the distant past, probably at least 1 billion years ago. What is left of one galaxy has become the rotating inner disk of old red stars in the center. Meanwhile, another smaller galaxy, which ventured too close, was probably severely damaged or destroyed. During the collision the gas from the smaller galaxy would have been stripped off and captured by the larger galaxy, forming a new ring of dust, gas, and stars, which orbit around the inner galaxy almost at right angles to the old disk. This is the polar ring that we see almost edge-on in this Hubble telescope view. Read more: * Release Text [ http://hubblesite.org/newscenter/archive/releases/1999/16/text/ ] |
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Massive Infant Stars Rock th
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| Title |
Massive Infant Stars Rock their Cradle |
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Magnificent Details in a Dus
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| Title |
Magnificent Details in a Dusty Spiral Galaxy |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. The Key Project team used this Hubble telescope view of the magnificent spiral galaxy, NGC 4414, to help calculate the expansion rate of the universe. Based on their discovery and careful brightness measurements of variable stars in this galaxy, the Key Project astronomers were able to make an accurate determination of the distance to the galaxy. The resulting distance to NGC 4414, about 60 million light-years, along with similarly determined distances to other nearby galaxies, contributes to astronomers' overall knowledge of the expansion rate of the cosmos, and helps them determine the age of the universe. |
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Colossal Cyclone Swirls near
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| Title |
Colossal Cyclone Swirls near Martian North Pole |
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Hubble Unveils a Galaxy in L
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| Title |
Hubble Unveils a Galaxy in Living Color |
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Hubble Images a Swarm of Anc
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| Title |
Hubble Images a Swarm of Ancient Stars |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. This stellar swarm is M80 (NGC 6093), one of the densest of the 147 known globular star clusters in the Milky Way Galaxy. Located about 28,000 light-years from Earth, M80 contains hundreds of thousands of stars, all held together by their mutual gravitational attraction. Globular clusters are particularly useful for studying stellar evolution, since all of the stars in the cluster have the same age (about 15 billion years), but cover a range of stellar masses. Every star visible in this image is either more highly evolved than, or in a few rare cases more massive than, our own Sun. Especially obvious are the bright red giants, which are stars similar to the Sun in mass that are nearing the ends of their lives. |
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Star Clusters Born in the Wr
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Star Clusters Born in the Wreckage of Cosmic Collisions |
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A Minuet of Galaxies
| Title |
A Minuet of Galaxies |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. This troupe of four galaxies, known as Hickson Compact Group 87 (HCG 87), is performing an intricate dance orchestrated by the mutual gravitational forces acting between them. The dance is a slow, graceful minuet, occurring over a time span of hundreds of millions of years. This Hubble telescope image reveals complex details in the dust lanes of the group's largest galaxy member (HCG 87a), which is actually disk-shaped, but tilted so that we see it nearly edge-on. Both 87a and its elliptically shaped nearest neighbor (87b) have active galactic nuclei, which are believed to harbor black holes that are consuming gas. A third group member, the nearby spiral galaxy 87c, may be undergoing a burst of active star formation. The three galaxies are so close to each other that gravitational forces disrupt their structure and alter their evolution. |
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Burst of Star Formation Driv
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| Title |
Burst of Star Formation Drives Bubble in Galaxy's Core |
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Hubble Sends Season's Greeti
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| Title |
Hubble Sends Season's Greetings from the Cosmos to Earth |
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A Grazing Encounter between
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| Title |
A Grazing Encounter between Two Spiral Galaxies |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Back to top [ #top ] |
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Hubble Heritage Project's Fi
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| Title |
Hubble Heritage Project's First Anniversary |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. To mark the first anniversary of the Hubble Heritage Project, we present four Hubble telescope images of nebulae surrounding stars in our own Milky Way Galaxy. Two of these visible-light pictures show interstellar gas and dust around young stars at the beginning of their lives, and two more show gas ejected from old stars that are nearing the end of theirs. Remarkably, in spite of the completely different evolutionary stages, the nebulae have more striking features in common, including evidence of diametrically opposed gas ejections from both the young and old stars. |
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Stellar 'Fireworks Finale' C
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| Title |
Stellar 'Fireworks Finale' Came First in the Young Universe |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
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Hubble Reveals "Backwards" S
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| Title |
Hubble Reveals "Backwards" Spiral Galaxy |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Back to top [ #top ] |
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The Glowing Eye of NGC 6751
| Title |
The Glowing Eye of NGC 6751 |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Back to top [ #top ] |
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Hubble Takes a Close-up View
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| Title |
Hubble Takes a Close-up View of a Reflection Nebula in Orion |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Back to top [ #top ] |
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Hubble Uncovers Oldest "Cloc
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| Title |
Hubble Uncovers Oldest "Clocks" in Space to Read Age of Universe |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
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A Cosmic Searchlight
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A Cosmic Searchlight |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Back to top [ #top ] |
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Movies from Hubble Show the
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Movies from Hubble Show the Changing Faces of Infant Stars |
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Movies from Hubble Show the
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| Title |
Movies from Hubble Show the Changing Faces of Infant Stars |
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IC 418: The "Spirograph" Neb
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IC 418: The "Spirograph" Nebula |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Back to top [ #top ] |
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Hubble Peeks into a Stellar
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| Title |
Hubble Peeks into a Stellar Nursery in a Nearby Galaxy |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Back to top [ #top ] |
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A Bird's Eye View of a Galax
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| Title |
A Bird's Eye View of a Galaxy Collision |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Back to top [ #top ] |
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