Caldwell-Katalog

A preliminary interpretation suggests that the star might be a double-star system. The dynamical effects of two stars orbiting one another most easily explains the intricate structures, which are much more complicated than features seen in most planetary nebulae. (The two stars are too close together to be individually resolved by Hubble, and instead, appear as a single point of light at the center of the nebula.)

According to this model, a fast "stellar wind" of gas blown off the central star created the elongated shell of dense, glowing gas. This structure is embedded inside two larger lobes of gas blown off the star at an earlier phase. These lobes are "pinched" by a ring of denser gas, presumably ejected along the orbital plane of the binary companion.

The suspected companion star also might be responsible for a pair of high- speed jets of gas that lie at right angles to this equatorial ring. If the companion were pulling in material from a neighboring star, jets escaping along the companion's rotation axis could be produced.

These jets would explain several puzzling features along the periphery of the gas lobes. Like a stream of water hitting a sand pile, the jets compress gas ahead of them, creating the "curlicue" features and bright arcs near the outer edge of the lobes. The twin jets are now pointing in different directions than these features. This suggests the jets are wobbling, or precessing, and turning on and off episodically.

This color picture, taken with the Wide Field Planetary Camera-2, is a composite of three images taken at different wavelengths. (red, hydrogen-alpha; blue, neutral oxygen, 6300 angstroms; green, ionized nitrogen, 6584 angstroms). The image was taken on September 18, 1994. NGC 6543 is 3,000 light-years away in the northern constellation Draco.

The term planetary nebula is a misnomer; dying stars create these cocoons when they lose outer layers of gas. The process has nothing to do with planet formation, which is predicted to happen early in a star's life.

Iridescent Glory of Nearby Helix Nebula.

About the Object

• Object Name: Helix Nebula, NGC 7293
• Object Description: Planetary Nebula
• Position (J2000): R.A. 22h 29m 48.20s

Dec. -20° 49' 26.0"

• Constellation: Aquarius
• Distance: About 650 light-years (200 parsecs)
• Dimensions: The image is roughly 27 arcminutes (5.1 light-years or 1.6 parsecs) across.

About the Data

• Data Description: Hubble data have been superimposed onto ground-based data taken by Travis Rector (NRAO) at the 0.9 meter telescope located on Kitt Peak, Tucson, AZ (NOAO/AURA/NSF). The HST data are from proposal 9700. Processed images may be obtained from the Helix MAST web site. The Hubble Helix Team includes M. Meixner, H.E. Bond, G. Chapman (STScI), Y.-H. Chu (U. Illinois, Urbana-Champaign), P. Cox (Institut d'Astrophysique Spatiale, France), W. Crothers, L.M. Frattare, R.Gilliland (STScI), M. Guerrero R. Gruendl (U. Illinois, Urbana-Champaign), F. Hamilton, (STScI), R.Hook (STScI/ESO), P. Huggins (New York Univ.), I. Jordan, C.D. Keyes, A. Koekemoer (STScI), K.Kwitter (Williams College), Z.G. Levay, P.R. McCullough, M. Mutchler, K. Noll (STScI), C.R. O'Dell (Vanderbilt Univ.), N. Panagia, M. Reinhart, M. Robberto, K. Sahu, D. Soderblom, L. Stanghellini, C. Tyler, J. Valenti, A. Welty, R. Williams (STScI).
• Instrument: ACS/WFC Mosaic I Camera on KPNO 0.9m telescope
• Exposure Date(s): November 19, 2002 November 3, 2001
• Exposure Time: 4.5 hours 25 minutes
• Filters: F502N ([O III]), F658N (H alpha) k1009 (H alpha), k1014 ([O III])

Aufnahme des Planetarischen Nebels NGC 40 mit einer Webcam an einem 14" SCT Autor: Klaus Hohmann

This image of the nearby edge-on en:Spiral Galaxy NGC 55 was taken by en:Galaxy Evolution Explorer on en:September 14, en:2003 during 2 orbits. This galaxy lies 5.4 million en:light years from the en:Milky Way galaxy and is a member of the "local group" of galaxies that also includes the en:Andromeda galaxy (M31), the en:Magellanic clouds, and 40 other galaxies. The spiral disk of NGC 55 is inclined to our line of sight by approximately 80 degrees and so this galaxy looks cigar shaped. This picture is a combination of Galaxy Evolution Explorer images taken with the far ultraviolet (colored blue) and near ultraviolet detectors, (colored red). The bright blue regions in this image are areas of active star formation detected in the ultraviolet by Galaxy Evolution Explorer. The red stars in this image are foreground stars in our own Milky Way galaxy.

Source of image & text

Taken on September 11, 2004 from [1]: JPL Galaxies Gallery

A perfect donut of a galaxy.

Data from the following proposal were used to create this image: PHANGS-HST: Linking Stars and Gas throughout the Scales of Star Formation

Red: WFC3/UVIS F814W Green: WFC3/UVIS F555W Blue : WFC3/UVIS F438W+F336W+F275W

SBIG ST-4000XCM
15x15min
Imager Temp -20C
APM/TMB 130/780
Field Flattener

• Source: Primary
• Image Credit: NASA/JPL-Caltech
• Image produced by: M. Regan (STScI), and the SINGS Team

The Wide Field Camera 3 (WFC3), a new camera aboard NASA's Hubble Space Telescope, snapped this image of the planetary nebula, catalogued as NGC 6302, but more popularly called the Bug Nebula or the Butterfly Nebula. WFC3 was installed by NASA astronauts in May 2009, during the servicing mission to upgrade and repair the 19-year-old Hubble telescope.

NGC 6302 lies within our Milky Way galaxy, roughly 3,800 light-years away in the constellation Scorpius. The glowing gas is the star's outer layers, expelled over about 2,200 years. The "butterfly" stretches for more than two light-years, which is about half the distance from the Sun to the nearest star, Alpha Centauri.

The central star itself cannot be seen, because it is hidden within a doughnut-shaped ring of dust, which appears as a dark band pinching the nebula in the center. The thick dust belt constricts the star's outflow, creating the classic "bipolar" or hourglass shape displayed by some planetary nebulae.

The star's surface temperature is estimated to be about 400,000 degrees Fahrenheit, making it one of the hottest known stars in our galaxy. Spectroscopic observations made with ground-based telescopes show that the gas is roughly 36,000 degrees Fahrenheit, which is unusually hot compared to a typical planetary nebula.

The WFC3 image reveals a complex history of ejections from the star. The star first evolved into a huge red-giant star, with a diameter of about 1,000 times that of our Sun. It then lost its extended outer layers. Some of this gas was cast off from its equator at a relatively slow speed, perhaps as low as 20,000 miles an hour, creating the doughnut-shaped ring. Other gas was ejected perpendicular to the ring at higher speeds, producing the elongated "wings" of the butterfly-shaped structure. Later, as the central star heated up, a much faster stellar wind, a stream of charged particles traveling at more than 2 million miles an hour, plowed through the existing wing-shaped structure, further modifying its shape.

The image also shows numerous finger-like projections pointing back to the star, which may mark denser blobs in the outflow that have resisted the pressure from the stellar wind.

The nebula's reddish outer edges are largely due to light emitted by nitrogen, which marks the coolest gas visible in the picture. WFC3 is equipped with a wide variety of filters that isolate light emitted by various chemical elements, allowing astronomers to infer properties of the nebular gas, such as its temperature, density, and composition.

The white-colored regions are areas where light is emitted by sulfur. These are regions where fast-moving gas overtakes and collides with slow-moving gas that left the star at an earlier time, producing shock waves in the gas (the bright white edges on the sides facing the central star). The white blob with the crisp edge at upper right is an example of one of those shock waves.

NGC 6302 was imaged on July 27, 2009, with Hubble's Wide Field Camera 3 in ultraviolet and visible light. Filters that isolate emissions from oxygen, helium, hydrogen, nitrogen, and sulfur from the planetary nebula were used to create this composite image.

Strangely glowing dark clouds float serenely in this remarkable and beautiful image taken with the Hubble Space Telescope. These dense, opaque dust clouds — known as globules — are silhouetted against nearby bright stars in the busy star-forming region, IC 2944.

Astronomer A.D. Thackeray first spied the globules in IC 2944 in 1950. Globules like these have been known since Dutch-American astronomer Bart Bok first drew attention to such objects in 1947.

This composite image traces star formation in progress. Young hot blue stars dominate the outer spiral arms of the galaxy, while the older stars congregate in the nuclear regions which appear yellow-green. Gases heated by hot young stars and shocks due to winds from massive stars and supernova explosions appear in pink, as revealed by the visible-light image of the galaxy.

NASA's new Spitzer Space Telescope, formerly known as the Space Infrared Telescope Facility, has captured in stunning detail the spidery filaments and newborn stars of the Tarantula Nebula, a rich star-forming region also known as 30 Doradus. This cloud of glowing dust and gas is located in the Large Magellanic Cloud, the nearest galaxy to our own Milky Way, and is visible primarily from the Southern Hemisphere. This image of an interstellar cauldron provides a snapshot of the complex physical processes and chemistry that govern the birth - and death - of stars.

At the heart of the nebula is a compact cluster of stars, known as R136, which contains very massive and young stars. The brightest of these blue supergiant stars are up to 100 times more massive than the Sun, and are at least 100,000 times more luminous. These stars will live fast and die young, at least by astronomical standards, exhausting their nuclear fuel in a few million years.

The Spitzer Space Telescope image was obtained with an infrared array camera that is sensitive to invisible infrared light at wavelengths that are about ten times longer than visible light. In this four-color composite, emission at 3.6 microns is depicted in blue, 4.5 microns in green, 5.8 microns in orange, and 8.0 microns in red. The image covers a region that is three-quarters the size of the full moon.

The Spitzer observations penetrate the dust clouds throughout the Tarantula to reveal previously hidden sites of star formation. Within the luminescent nebula, many holes are also apparent. These voids are produced by highly energetic winds originating from the massive stars in the central star cluster. The structures at the edges of these voids are particularly interesting. Dense pillars of gas and dust, sculpted by the stellar radiation, denote the birthplace of future generations of stars.

The Spitzer image provides information about the composition of the material at the edges of the voids. The surface layers closest to the massive stars are subject to the most intense stellar radiation. Here, the atoms are stripped of their electrons, and the green color of these regions is indicative of the radiation from this highly excited, or 'ionized,' material. The ubiquitous red filaments seen throughout the image reveal the presence of molecular material thought to be rich in hydrocarbons.

The Rosette Nebula (also known as NGC 2237) is a large, circular H II region located near one end of a giant molecular cloud in the Monoceros constellation. Photographed at La Palma, Roque de los Muchachos (Degollada de los Franceses). Photo taken the following equipement:

• Camera/Telecope: Pentax SDHF 500 6.7/500 on GP/DX, tracing ST4 at 600mm (Sonnar 4/300 with 2x tele converter)
• Exposure: 45 min
• Film: Kodak E200 35mm (Push to 600 ASA)
• Scanner: Scan service
• Processing: Removed vignetting, colour and contrast correction.
• additional remark: faintest object visible at 6.5 mag

In a spiral galaxy like IC 342, dust and gas are concentrated in the arms. The denser pockets of gas trigger the formation of new stars, as represented here in green and yellow. The core, shown in red, is also bursting with young stars, which are heating up dust. Stars that appear blue reside within our Milky Way, between us and IC 342.

This galaxy has been of great interest to astronomers because it is relatively close. However, determining its distance from Earth has proven difficult due to the intervening Milky Way. Astronomer Edwin Hubble first thought the galaxy might belong to our own Local Group of galaxies, but current estimates now place it farther away, at about 6.6 to 11 million light-years.

In this Hubble telescope image, the "parka" is really a disk of material embellished with a ring of comet-shaped objects, with their tails streaming away from the central, dying star. The Eskimo's "face" also contains some fascinating details. Although this bright central region resembles a ball of twine, it is, in reality, a bubble of material being blown into space by the central star's intense "wind" of high-speed material.

In this photo, one bubble lies in front of the other, obscuring part of the second lobe. Scientists believe that a ring of dense material around the star's equator, ejected during its red giant phase, created the nebula's shape. The bubbles are not smooth like balloons but have filaments of denser matter. Each bubble is about 1 light-year long and about half a light-year wide.

Scientists are still puzzled about the origin of the comet-shaped features in the "parka." One possible explanation is that these objects formed from a collision of slow-and fast-moving gases.