The Multitude of Molecular Hydrogen Knots in the Helix Nebula 1
... distance because the individual knots have a small range of intensities. Positions that overlap in radial distance, 1 & 2 and 4 & 5, are offset in their optical line emissions because they are located at very different azimuthal positions and the nebula has a distinct variation with azimuthal angle. ...
... distance because the individual knots have a small range of intensities. Positions that overlap in radial distance, 1 & 2 and 4 & 5, are offset in their optical line emissions because they are located at very different azimuthal positions and the nebula has a distinct variation with azimuthal angle. ...
The redshift of extragalactic nebulae
... spheroid, often elliptical, and many of them have a spiral-like appearance, for which reason they are sometimes designated as spiral nebulae. Thanks to the enormous resolving power of modern giant telescopes, it was possible to determine that these nebulae lie outside the boundaries of our own Milky ...
... spheroid, often elliptical, and many of them have a spiral-like appearance, for which reason they are sometimes designated as spiral nebulae. Thanks to the enormous resolving power of modern giant telescopes, it was possible to determine that these nebulae lie outside the boundaries of our own Milky ...
Physical Properties of the Gas and Dust in the Orion B Molecular
... they are not the progenitors of individual stars. The “real” protostellar condensations are often overlooked in molecular line surveys although they should in principle be seen, e.g., in higher CS transitions. A basic problem of spectral line observations towards cold dense condensations is the fact ...
... they are not the progenitors of individual stars. The “real” protostellar condensations are often overlooked in molecular line surveys although they should in principle be seen, e.g., in higher CS transitions. A basic problem of spectral line observations towards cold dense condensations is the fact ...
Timescales for the evolution of oxygen isotope compositions in the
... D17O values were detected among the grains (11 ± 4 < D17O < +33 ± 3&), confirming all earlier results. However the negative D17O values were not as extreme as those observed by Hashizume and Chaussidon (2005) (<20&), likely due to the increased contribution of the normal components (D17O = 0 &) com ...
... D17O values were detected among the grains (11 ± 4 < D17O < +33 ± 3&), confirming all earlier results. However the negative D17O values were not as extreme as those observed by Hashizume and Chaussidon (2005) (<20&), likely due to the increased contribution of the normal components (D17O = 0 &) com ...
Sample pages 1 PDF
... and the Orion Nebula is no exception. Long-exposure photographs reveal all sorts of complex features, including star clusters, reflection nebulae, and clouds of gas and dust. The Hubble Telescope has also shown evidence of protoplanetary discs, known as proplyds, meaning that at least some of the yo ...
... and the Orion Nebula is no exception. Long-exposure photographs reveal all sorts of complex features, including star clusters, reflection nebulae, and clouds of gas and dust. The Hubble Telescope has also shown evidence of protoplanetary discs, known as proplyds, meaning that at least some of the yo ...
Observations of Jets and Outflows from Young Stars
... knots of Hα and/or forbidden line emission are produced. The primary jets and winds transfer momentum and entrain their surroundings by means of shock waves propagating into the medium. These shocks tend to have much lower velocities than the jets; they can be seen in H2 emission when the interactio ...
... knots of Hα and/or forbidden line emission are produced. The primary jets and winds transfer momentum and entrain their surroundings by means of shock waves propagating into the medium. These shocks tend to have much lower velocities than the jets; they can be seen in H2 emission when the interactio ...
The ISO–SWS Spectrum of Planetary Nebula NGC 7027
... (I < 5, where I is in 10−12 erg cm−2 s−1 ) have estimated errors of about 20%, intermediate lines (5 < I < 10) of about 10%, while the strongest lines (I > 10), have normally less than 5% uncertainty. All the lines follow this behavior with the exception of the S III line at 33.5 µm with a measured ...
... (I < 5, where I is in 10−12 erg cm−2 s−1 ) have estimated errors of about 20%, intermediate lines (5 < I < 10) of about 10%, while the strongest lines (I > 10), have normally less than 5% uncertainty. All the lines follow this behavior with the exception of the S III line at 33.5 µm with a measured ...
The Physics and Chemistry of Nebular Evolution
... guides for understanding solar nebula chemistry over the last few decades. As reviewed by Ebel (2006), condensation calculations provide information about the direction of chemical evolution, telling us what the end products would be in a system given a constant chemical inventory, infinite time, an ...
... guides for understanding solar nebula chemistry over the last few decades. As reviewed by Ebel (2006), condensation calculations provide information about the direction of chemical evolution, telling us what the end products would be in a system given a constant chemical inventory, infinite time, an ...
The Oort cloud as a remnant of the protosolar nebula
... Assuming the creation of cometary nuclei in molecular clouds, it seems to be reasonable to suppose that their number density in an element of volume is roughly linearly proportional to the density of cloud material in this volume. The mathematical cloud model described by Eqs. (10) and (11) extends ...
... Assuming the creation of cometary nuclei in molecular clouds, it seems to be reasonable to suppose that their number density in an element of volume is roughly linearly proportional to the density of cloud material in this volume. The mathematical cloud model described by Eqs. (10) and (11) extends ...
SPATIAL STUDY WITH THE VERY LARGE TELESCOPE OF A NEW
... (VLT) under 0>4 seeing conditions, which unveil a dark dust lane oriented east-west between two characteristic northern and southern reflection nebulae. This new circumstellar dust disk has a radius of 2>15 (300 AU at 140 pc) and a width of 1>2 (170 AU at 140 pc). Thanks to its location at the periph ...
... (VLT) under 0>4 seeing conditions, which unveil a dark dust lane oriented east-west between two characteristic northern and southern reflection nebulae. This new circumstellar dust disk has a radius of 2>15 (300 AU at 140 pc) and a width of 1>2 (170 AU at 140 pc). Thanks to its location at the periph ...
The Life and Work of Edward Emerson Barnard
... larger scale of the Bruce telescope, and in the search for diffused nebulosities Barnard exposed a large number of plates on the upper part of the Scorpion. 63 Many of the plates, by chance, recorded the trails of faint asteroids, and on three plates exposed on July 22, 1905, he recorded the trail o ...
... larger scale of the Bruce telescope, and in the search for diffused nebulosities Barnard exposed a large number of plates on the upper part of the Scorpion. 63 Many of the plates, by chance, recorded the trails of faint asteroids, and on three plates exposed on July 22, 1905, he recorded the trail o ...
What To See Telescope(Jul-Sept) v1 - One
... Your telescope may have come with at least two eyepieces, and you may have acquired one or two more. It’s important to know the magnification each of your eyepieces give you, and if possible, the field of view of each eyepiece in degrees. If you do not know how to determine these numbers, look to th ...
... Your telescope may have come with at least two eyepieces, and you may have acquired one or two more. It’s important to know the magnification each of your eyepieces give you, and if possible, the field of view of each eyepiece in degrees. If you do not know how to determine these numbers, look to th ...
Late Summer Messier Objects
... companion Herschel 36 to the WSW, are the primary illuminators of M8, just as star C in the Trapezium is the primary illuminator of M42. Like the Trapezium stars, 9 Sgr and Herschel 36 are O-type stars emitting the great majority of their energy in the ultraviolet spectrum, and causing the hydrogen ...
... companion Herschel 36 to the WSW, are the primary illuminators of M8, just as star C in the Trapezium is the primary illuminator of M42. Like the Trapezium stars, 9 Sgr and Herschel 36 are O-type stars emitting the great majority of their energy in the ultraviolet spectrum, and causing the hydrogen ...
SciPoster_Jan2009
... Another isolated dark nebula is LDN 425. While it is not directly associated with any molecular cloud complex, there is mention of an extended distribution of dust between the main clouds in Chamaeleon, Lupus and Ophiuchus (Sartori 2000). Ophiuchus is another region of active star formation, much of ...
... Another isolated dark nebula is LDN 425. While it is not directly associated with any molecular cloud complex, there is mention of an extended distribution of dust between the main clouds in Chamaeleon, Lupus and Ophiuchus (Sartori 2000). Ophiuchus is another region of active star formation, much of ...
Planetary Nebulae: Observational Properties, Mimics, and Diagnostics
... integrated flux, surface brightness, excitation class, central star magnitude, and evolutionary state shown by individual PN, a large and diverse range of detection methods has been used in their discovery. Some of the brightest and best-known PNe were found over two centuries ago at the telescope e ...
... integrated flux, surface brightness, excitation class, central star magnitude, and evolutionary state shown by individual PN, a large and diverse range of detection methods has been used in their discovery. Some of the brightest and best-known PNe were found over two centuries ago at the telescope e ...
to - NexStar Resource Site
... Although Galileo was the first to observe it with a telescope in 1610, Saturn has been known since prehistoric times. Up to 1977 Saturn was believed to be the only planet with a ring system. It was later discovered that all of the gas planets had ring systems, albeit faint, of their own. Saturn is a ...
... Although Galileo was the first to observe it with a telescope in 1610, Saturn has been known since prehistoric times. Up to 1977 Saturn was believed to be the only planet with a ring system. It was later discovered that all of the gas planets had ring systems, albeit faint, of their own. Saturn is a ...
Presolar Cloud Collapse and the Formation and Early Evolution of
... 2.2.1. Ambipolar diffusion and loss of magnetic support. Magnetic field strengths in dense clouds are measured by Zeeman splitting of molecular lines, and found to be large enough (about 10–1000 µG) to be capable of supporting dense clouds, provided that both static magnetic fields and magnetohydrod ...
... 2.2.1. Ambipolar diffusion and loss of magnetic support. Magnetic field strengths in dense clouds are measured by Zeeman splitting of molecular lines, and found to be large enough (about 10–1000 µG) to be capable of supporting dense clouds, provided that both static magnetic fields and magnetohydrod ...
The Clouds
... young stars. The bright stars light up the cloud material nearby producing the magnificent Orion Nebula which we see in reflected light. In addition, molecular gas is photo-dissociated by the far-ultraviolet radiation from the OB stars, producing very strong infrared emission in the fine-structure l ...
... young stars. The bright stars light up the cloud material nearby producing the magnificent Orion Nebula which we see in reflected light. In addition, molecular gas is photo-dissociated by the far-ultraviolet radiation from the OB stars, producing very strong infrared emission in the fine-structure l ...
Folie 1
... How to answer some of these? Monitor the brightness of many YSOs over a long period of time. ...
... How to answer some of these? Monitor the brightness of many YSOs over a long period of time. ...
Star Formation in the Rosette Complex
... The pioneering observations by Gosachinskii & Khersonskii (1982) of the HI emission at 21 cm made with the RATAN-600 telescope revealed that the Rosette Complex and the Monoceros Loop were enclosed in a thin HI envelope 130 pc in diameter, possibly expanding at 20 km·s−1 , suggesting that the supern ...
... The pioneering observations by Gosachinskii & Khersonskii (1982) of the HI emission at 21 cm made with the RATAN-600 telescope revealed that the Rosette Complex and the Monoceros Loop were enclosed in a thin HI envelope 130 pc in diameter, possibly expanding at 20 km·s−1 , suggesting that the supern ...
Unraveling the Helix Nebula: Its Structure and Knots
... We describe the new high resolution HST and broader field of view (FOV) ground-based observations in § 2. In § 3 we describe the analysis of these new observations and discuss these results in § 4. What we find is that the Helix Nebula is composed of an inner-disk of material, surrounded by a lower ...
... We describe the new high resolution HST and broader field of view (FOV) ground-based observations in § 2. In § 3 we describe the analysis of these new observations and discuss these results in § 4. What we find is that the Helix Nebula is composed of an inner-disk of material, surrounded by a lower ...
Chapter 1
... The constellation of Orion is one of the most discernable patterns in the northern hemisphere, and has acted as an important beacon for generations throughout history. Orion stands central in many mythological tales. One of my personal favorites describes the figure of Orion, the hunter, standing by ...
... The constellation of Orion is one of the most discernable patterns in the northern hemisphere, and has acted as an important beacon for generations throughout history. Orion stands central in many mythological tales. One of my personal favorites describes the figure of Orion, the hunter, standing by ...
Orion Nebula
The Orion Nebula (also known as Messier 42, M42, or NGC 1976) is a diffuse nebula situated in the Milky Way, being south of Orion's Belt in the constellation of Orion. It is one of the brightest nebulae, and is visible to the naked eye in the night sky. M42 is located at a distance of 1,344 ± 20 light years and is the closest region of massive star formation to Earth. The M42 nebula is estimated to be 24 light years across. It has a mass of about 2000 times the mass of the Sun. Older texts frequently refer to the Orion Nebula as the Great Nebula in Orion or the Great Orion Nebula.The Orion Nebula is one of the most scrutinized and photographed objects in the night sky, and is among the most intensely studied celestial features. The nebula has revealed much about the process of how stars and planetary systems are formed from collapsing clouds of gas and dust. Astronomers have directly observed protoplanetary disks, brown dwarfs, intense and turbulent motions of the gas, and the photo-ionizing effects of massive nearby stars in the nebula.