![]() Caption:The nebulosity around this cool star is from light reflected by grains of dust surrounding it. The dust originates from the star and is believed to consist mainly of particles of silica condensed from its outer layers. The rate of mass loss is much higher than normal in stars of this kind and is sufficient to produce the reflection nebula IC 2220. The stellar nature of the central object is revealed by the cross-like spikes extending from it. These are artifacts due to structures within the telescope. Copyright:(c) 1980 Anglo-Australian Telescope Board, photograph by David Malin Credit:D. F. Malin |
![]() Caption:Wolf-Rayet stars are massive, extremely hot stars ejecting material from their seething surfaces with velocities of thousands of kilometers per second. In the case of NGC 2359, the stellar wind is interacting with the gas and dust around the star producing the cosmic bubble seen here. The shell-like layers are formed by a single star, HD 56925, shedding a substantial fraction of its outer substance into a part of our Galaxy rich in interstellar gas. Such stars are unusual, mainly because extreme behavior of this kind cannot be sustained for long. Copyright:(c) 1979 Anglo-Australian Telescope Board, photograph by David Malin Credit:D. F. Malin |
![]() Caption:Beta Pictoris is a 4th magnitude star which emits strongly in the infrared. It is surrounded by a disk of material of the kind believed in time to result in the creation of a planetary system. Copyright: Credit:National Optical Astronomy Observatories |
![]() Caption:Very hot, massive stars lose mass from their surfaces during much of their brief lives. Mass-loss is usually a fairly steady process but some stars occasionally have major outbursts. This star has thrown off at least two distinct lots of material during its lifetime, the brightest and most recent being NGC 6164-5 at the center of the picture, while a much fainter, older rim of nebulosity can be seen at a considerable distance from the central star, indicating an earlier episode of violent ejection. Copyright:(c) 1984 Anglo-Australian Telescope Board, photograph by David Malin Credit:D F Malin |
![]() Caption:The bright central star seen here is known only as HD 148937, and is the hottest member of a young triple system of stars in orbit around each other, so, despite its superficially similarity to a planetary nebula, this is in fact a rather unusual object. The very luminous star is losing mass from its outer layers continuously but occasionally more vigorous outbursts give rise to the symmetrical shells seen in this picture. The two catalogue numbers, NGC 6164 and 6165, refer to these shells as separate objects. Copyright:(c) 1981 Anglo-Australian Telescope Board, photograph by David Malin Credit:D. F. Malin |
![]() Caption:A Hubble Space Telescope view of a small portion of the Orion Nebula (0.14 light years across) reveals five young stars. Four are surrounded by gas and dust that was trapped as the stars formed. These are possibly protoplanetary disks or "proplyds," which may go on to evolve into planetary systems. Those closest to the hottest stars in their cluster look bright, while one further away is seen dark. Copyright: Credit:C. R. O'Dell and NASA |
![]() Caption:The pictures show an 8th-magnitude red-dwarf star (Gliese 229), located approximately 18 light-years away in the constellation Lepus. A far fainter companion Gliese 229B was revealed on October 27, 1994. Its orbital semimajor axis is 44 AU. The object's mass is about 20 - 50 Jupiters, but is so dense it is about the same diameter as Jupiter (80,000 miles). The partner's properties - a low surface temperature and a methane-bearing atmosphere - prove it to be a substellar brown dwarf. The image at left, taken in far-red light with an adaptive-optics coronagraph on the Palomar Mountain 1.5-meter telescope (October, 1994). The one at right, obtained by the Hubble Space Telescope (November, 1995), confirms that the faint speck, named Gliese 229B, indeed orbit its parent star. Copyright:T.Nakajima (Caltech), S.Durrance (JHU) (left); S.Kulkarni (Caltech), D.Golimowski (JHU), and NASA Credit: |
![]() Caption:A Hubble Space Telescope view of a very young star (between 300,000 and a million years of age) surrounded by material left over from the star's formation. The cool, reddish star is about one fifth the mass of our Sun. The dark disk, seen in silhouette against the background of the Orion Nebula, is possibly a protoplanetary disk from which planets will form. The disk contains at least seven times the material as our Earth. The disk is 56 billion miles across (90 billion kilometers), or 7.5 times the diameter of our Solar System.The Orion Nebula starbirth region is 1,500 light-years away, in the direction of the constellation Orion the Hunter. Copyright:C.R. O'Dell/Rice University, NASA Credit: |
![]() Caption:This image from Hubble Space Telescope shows for the first time the inner region of a 200-billion mile diameter dust disk around the star Beta Pictoris. Top: This is a visible light image of the disk, which appears spindle-like because it is tilted nearly edge-on to our view. The disk is made up of microscopic dust grains of ices and silicate particles. The central clearing is occupied by one or more planets. The bright star, which lies at the center of the disk, is blocked out in this image. Bottom: False-color is applied through image processing to accentuate details in the disk structure. Hubble reveals that the pink-white inner edge of the disk is slightly tilted from the plane of the outer disk (red-yellow-green) as identified by a dotted line. A simple explanation is that a large planet is pulling on the disk. It is not possible to see the planet directly because it is close to the star, and perhaps a billion-times fainter. Copyright: Credit:C. Burrows, Space Telescope Science Institute (STScI) the European Space Agency (ESA), J. Krist (STScI), the WFPC2 IDT team, and NASA |
![]() Caption:This Hubble Space Telescope image reveals new secrets of star birth as revealed in a pair of eerie spectacular jet of gas the star has ejected by a young star. Top: Tip to tip, this jet spans slightly more than a light-year. The fountainhead of this structure -- the young star -- lies midway between the jet, and is hidden from view behind a dark cloud of dust. The nearly symmetrical blobs of gas at either end are where the jet has slammed into interstellar gas. Bottom left: A close-up of a region near the star reveals a string of glowing clumps of gas, ejected by the star in machine-gun like burst fashion. Bottom right: This arrowhead structure is a classic bowshock pattern produced when high-speed material encounters a slower-speed medium. Copyright: Credit:J. Hester (Arizona State University), the WFPC 2 Investigation Definition Team, and NASA |
![]() Caption:An artist's impression of a double star in the globular cluster NGC 6624 which is a source of powerful bursts of X-ray emission. It consists of a neutron star, surrounded by a disk of material, partnered by a white dwarf that is shedding material onto the disk across a narrow bridge. The Hubble Space Telescope detected ultraviolet emission from the disk in 1993. Copyright: Credit:D. Berry/ STScI |
![]() Caption:A rapidly expanding shell of material surrounding Eta Carinae ejected during a violent outburst observed in the year 1841, imaged by the Hubble Space Telescope in January 1994. Eta Carina is one of the most massive and luminous stars known, with a mass 150 times that of the Sun Copyright: Credit:J. Hester and NASA |
![]() Caption:The development of the shell of gas surrounding Nova Cygni 1992, which erupted on 19 February 1992, in Hubble Space Telescope images made on 31 May 1993 and shortly after the December 1993 servicing mission. The nova was caused by a thermonuclear explosion on the surface of white dwarf star in a double star system. Copyright: Credit:F. Paresce, R. Jedrzejewski and NASA |