Star Formation in Our Galaxy - Wiley-VCH
... Figure 1.1 A portion of the Northern sky. The Milky Way is depicted as light grey, while the darker patches indicate giant molecular clouds. Also shown, according to their relative brightness, are the more prominent stars, along with principle constellations. ...
... Figure 1.1 A portion of the Northern sky. The Milky Way is depicted as light grey, while the darker patches indicate giant molecular clouds. Also shown, according to their relative brightness, are the more prominent stars, along with principle constellations. ...
Ecosystems, from life, to the Earth, to the Galaxy
... Our Milky Way galaxy displays the same characteristics that we associate with ecosystems if we view it on appropriately large scales of distance and time. This can most clearly be seen if we take an imaginary trip outside our Galaxy, to view it from afar. Seen face-on the Galaxy appears as a spiral, ...
... Our Milky Way galaxy displays the same characteristics that we associate with ecosystems if we view it on appropriately large scales of distance and time. This can most clearly be seen if we take an imaginary trip outside our Galaxy, to view it from afar. Seen face-on the Galaxy appears as a spiral, ...
KINEMATIC DISCOVERY OF A STELLAR STREAM LOCATED IN
... RGB stars shown in Figure 1, we selected a smaller velocity range of 75 km s−1 < vgsr < 115 km s−1 . We plotted the positions of stars in Galactic coordinates, and noted that many of these velocity-selected giant stars with metallicities between −2.8 < [Fe/H] < −1.8 are concentrated in a small fract ...
... RGB stars shown in Figure 1, we selected a smaller velocity range of 75 km s−1 < vgsr < 115 km s−1 . We plotted the positions of stars in Galactic coordinates, and noted that many of these velocity-selected giant stars with metallicities between −2.8 < [Fe/H] < −1.8 are concentrated in a small fract ...
Wednesday, Sept. 24 - Department of Physics and Astronomy
... • What can we do with this information? • If 2 stars have the same elements, same density, and same temperature then they have the same intrinsic luminosity. • If they have the same intrinsic luminosity we can use their apparent brightnesses to derive their relative distances using the Inverse Squar ...
... • What can we do with this information? • If 2 stars have the same elements, same density, and same temperature then they have the same intrinsic luminosity. • If they have the same intrinsic luminosity we can use their apparent brightnesses to derive their relative distances using the Inverse Squar ...
Chemical Evolution
... each GC was formed in situ or in a satellite galaxy and subsequently accreted onto the Milky Way (Roediger et al arxiv 1310.3275) • High abundances (1.7-2.5x solar) indicates that GCs formed rapidly before type Ia's contributed much to the gas (~1 Gyr) • However their remains puzzling patterns in ho ...
... each GC was formed in situ or in a satellite galaxy and subsequently accreted onto the Milky Way (Roediger et al arxiv 1310.3275) • High abundances (1.7-2.5x solar) indicates that GCs formed rapidly before type Ia's contributed much to the gas (~1 Gyr) • However their remains puzzling patterns in ho ...
Globular Clusters
... are stars that have passed the red giant phase, lost much of their outer shell, and are now small, hot, blue stars, fusing helium. They are considerably dimmer than the brightest red giants, but they can still be visible in photographs or with large telescopes. Blue Stragglers Dimmer yet, but still ...
... are stars that have passed the red giant phase, lost much of their outer shell, and are now small, hot, blue stars, fusing helium. They are considerably dimmer than the brightest red giants, but they can still be visible in photographs or with large telescopes. Blue Stragglers Dimmer yet, but still ...
Exam 2
... example, some of the heavy elements (such as carbon, nitrogen and oxygen) that form in a star’s core move into its outer layers. The abundance of these elements in a planetary nebula can show how material mixes through the various parts of a star’s interior. The expanding nebula merges with the inte ...
... example, some of the heavy elements (such as carbon, nitrogen and oxygen) that form in a star’s core move into its outer layers. The abundance of these elements in a planetary nebula can show how material mixes through the various parts of a star’s interior. The expanding nebula merges with the inte ...
Distance to the SMC
... classified into two general age categories. Population I stars are relatively young and formed after the interstellar medium was enriched with metals from the explosions of supernova and the deaths of other stars. Our Sun is a population I star. Population II stars formed early in the history of the ...
... classified into two general age categories. Population I stars are relatively young and formed after the interstellar medium was enriched with metals from the explosions of supernova and the deaths of other stars. Our Sun is a population I star. Population II stars formed early in the history of the ...
Galactic Archaeology: Current Surveys
... The spectra from the SDSS surveys provide line-of-sight velocities to around 10 km/s. The values of the stellar atmospheric parameters are obtained through a dedicated pipeline (Lee et al. 2008), developed for the broad range of targets and giving metallicity estimates to ∼ 0.2 dex, and for high sig ...
... The spectra from the SDSS surveys provide line-of-sight velocities to around 10 km/s. The values of the stellar atmospheric parameters are obtained through a dedicated pipeline (Lee et al. 2008), developed for the broad range of targets and giving metallicity estimates to ∼ 0.2 dex, and for high sig ...
Notes (PowerPoint)
... • Five visible planets Mercury, Venus, Mars, Jupiter, Saturn move with respect to stars o Uranus, Neptune, Pluto require telescope ...
... • Five visible planets Mercury, Venus, Mars, Jupiter, Saturn move with respect to stars o Uranus, Neptune, Pluto require telescope ...
Neon abundances - UCL Astrophysics Group
... Explorer (IUE) on the ultraviolet resonance lines of iron-peak elements in 26 HgMn, four superficially normal and 10 normal stars. We observed definite detections or determined upper limits for Ne i in 21 of the HgMn stars in the Smith & Dworetsky (1993) sample, and in 11 of the normal and superfici ...
... Explorer (IUE) on the ultraviolet resonance lines of iron-peak elements in 26 HgMn, four superficially normal and 10 normal stars. We observed definite detections or determined upper limits for Ne i in 21 of the HgMn stars in the Smith & Dworetsky (1993) sample, and in 11 of the normal and superfici ...
Document
... Almost every dSph has at least one RR Lyrae star → use distant RR Lyrae stars as tracers of low-luminosity dSphs ...
... Almost every dSph has at least one RR Lyrae star → use distant RR Lyrae stars as tracers of low-luminosity dSphs ...
Notes for Class 7, March 2
... • Used ellipse as an aid to calculations for years while insisting orbit was egg-shaped • Calculations were laying the foundation for calculus (invented by Newton later) – theory of area of irregular shapes • Clued in by numerical relationship which seemed at first like a coincidence • K: “The roads ...
... • Used ellipse as an aid to calculations for years while insisting orbit was egg-shaped • Calculations were laying the foundation for calculus (invented by Newton later) – theory of area of irregular shapes • Clued in by numerical relationship which seemed at first like a coincidence • K: “The roads ...
How do stars orbit in our galaxy?
... layers of dusty spiral arms. Visible light cannot penetrate. But … ...
... layers of dusty spiral arms. Visible light cannot penetrate. But … ...
IAU-Perraut-2013 - Putting A Stars into Context
... IAU Conference « Putting A Stars into Context” Moscow, 2013 June 3rd ...
... IAU Conference « Putting A Stars into Context” Moscow, 2013 June 3rd ...
HR DIAGRAM (Page 1) - McDonald Observatory
... the brightest star in the sky, mainly because it lies so close to us at a mere 9 light years away. Procyon is only 11 light years away, and is a F5 V stellar type. It is cooler than Sirius, and thus less luminous. Alpha Centauri A and the Sun could be considered “twin” stars. They are the same stell ...
... the brightest star in the sky, mainly because it lies so close to us at a mere 9 light years away. Procyon is only 11 light years away, and is a F5 V stellar type. It is cooler than Sirius, and thus less luminous. Alpha Centauri A and the Sun could be considered “twin” stars. They are the same stell ...
Impact on stellar properties of changing physics SAC Summer
... Figure 5: Main-sequence evolutionary tracks of stars with low (left panel) and intermediate (right panel) mass. K. Then the entire core will begin to fuse helium to carbon via the triple-alpha process. The resulting energy release occurs almost explosively. However, most of the energy is absorbed b ...
... Figure 5: Main-sequence evolutionary tracks of stars with low (left panel) and intermediate (right panel) mass. K. Then the entire core will begin to fuse helium to carbon via the triple-alpha process. The resulting energy release occurs almost explosively. However, most of the energy is absorbed b ...
Magnetic fields in O-, B-and A-type stars on the main sequence
... Magnetic fields have first been discovered in the Sun [1] and in the chemically peculiar A-type star 78 Virginis [2]. These two stars are representative of two major groups of magnetic stars, which are directly related to the dominant mechanism of heat transport in the outer layers of the stars. For ...
... Magnetic fields have first been discovered in the Sun [1] and in the chemically peculiar A-type star 78 Virginis [2]. These two stars are representative of two major groups of magnetic stars, which are directly related to the dominant mechanism of heat transport in the outer layers of the stars. For ...
Atoms and Stars IST 3360 and IST 1990
... • Five visible planets Mercury, Venus, Mars, Jupiter, Saturn move with respect to stars o Uranus, Neptune, Pluto require telescope ...
... • Five visible planets Mercury, Venus, Mars, Jupiter, Saturn move with respect to stars o Uranus, Neptune, Pluto require telescope ...
Today in Astronomy 142: observations of stars
... • Far infrared emission from stars is often not from the stellar photosphere but from circum-planetary dust that absorbs light from the star and reradiates it at longer wavelengths (of order 100K). ...
... • Far infrared emission from stars is often not from the stellar photosphere but from circum-planetary dust that absorbs light from the star and reradiates it at longer wavelengths (of order 100K). ...
Lecture 15 Star Formation and Evolution 3/7
... Change radius and surface temperature in late stages of stars’ life cycles ...
... Change radius and surface temperature in late stages of stars’ life cycles ...
The masses of stars
... surface temperature (T) and luminosity (L), which are related to one another through the radius of the star. If we want to understand more about the differences between stars, then the best place to start is by comparing the distribution of these properties in a graph of L against T. Whether plotted ...
... surface temperature (T) and luminosity (L), which are related to one another through the radius of the star. If we want to understand more about the differences between stars, then the best place to start is by comparing the distribution of these properties in a graph of L against T. Whether plotted ...
The evolution of stars - School of Physics
... underlying physical link between these properties. What is this link? For example, consider an alien scientist constructing a similar diagram ...
... underlying physical link between these properties. What is this link? For example, consider an alien scientist constructing a similar diagram ...
Booklet 5 – Stellar Processes and Evolution
... over time. All stars, irrespective of their mass spend most of their lifetime on the Main Sequence - the diagonal band spanning from top left to lower right. Stars of differing mass exist at different points along the main sequence. The more massive a star the further up and left it appears. As all ...
... over time. All stars, irrespective of their mass spend most of their lifetime on the Main Sequence - the diagonal band spanning from top left to lower right. Stars of differing mass exist at different points along the main sequence. The more massive a star the further up and left it appears. As all ...
Primas
... Caused by small cells of moDon in the photosphere (treated like an addiDonal thermal velocity in the line absorpDon coefficient) ...
... Caused by small cells of moDon in the photosphere (treated like an addiDonal thermal velocity in the line absorpDon coefficient) ...
Stellar classification
In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Light from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the rainbow of colors interspersed with absorption lines. Each line indicates an ion of a certain chemical element, with the line strength indicating the abundance of that ion. The relative abundance of the different ions varies with the temperature of the photosphere. The spectral class of a star is a short code summarizing the ionization state, giving an objective measure of the photosphere's temperature and density.Most stars are currently classified under the Morgan–Keenan (MK) system using the letters O, B, A, F, G, K, and M, a sequence from the hottest (O type) to the coolest (M type). Each letter class is then subdivided using a numeric digit with 0 being hottest and 9 being coolest (e.g. A8, A9, F0, F1 form a sequence from hotter to cooler). The sequence has been expanded with classes for other stars and star-like objects that do not fit in the classical system, such class D for white dwarfs and class C for carbon stars.In the MK system a luminosity class is added to the spectral class using Roman numerals. This is based on the width of certain absorption lines in the star's spectrum which vary with the density of the atmosphere and so distinguish giant stars from dwarfs. Luminosity class 0 or Ia+ stars for hypergiants, class I stars for supergiants, class II for bright giants, class III for regular giants, class IV for sub-giants, class V for main-sequence stars, class sd for sub-dwarfs, and class D for white dwarfs. The full spectral class for the Sun is then G2V, indicating a main-sequence star with a temperature around 5,800K.