Life of a Star Observations
... When stars form, they usually form into clusters. Some clusters, such as open clusters are loose and last only for a few hundred million to a few billion years before the stars dissipate into individual stars. Other star clusters, such as globular clusters, remain fairly stable for billions of years ...
... When stars form, they usually form into clusters. Some clusters, such as open clusters are loose and last only for a few hundred million to a few billion years before the stars dissipate into individual stars. Other star clusters, such as globular clusters, remain fairly stable for billions of years ...
2015 SAO Summer Intern AAS Abstracts - Harvard
... planets with periods between 10 to 100 days. This gap could be caused by something as simple as observational bias, or as prominent as planetary formation or migration. Here, we report an investigation into the atmosphere of planets within this orbital period valley, to search for differences that m ...
... planets with periods between 10 to 100 days. This gap could be caused by something as simple as observational bias, or as prominent as planetary formation or migration. Here, we report an investigation into the atmosphere of planets within this orbital period valley, to search for differences that m ...
Basic Tools for Studies on the Formation and Disruption of Star
... systematic decrease of the (logarithmic) slope from roughly −1.8 at low luminosities to roughly −2.8 at high luminosities. The empirical LFs can be reproduced by model LFs using an underlying cluster IMF with a Schechter type truncation around M∗ ≈ 2 × 105 M⊙ . This value of M⋆ can not be universal ...
... systematic decrease of the (logarithmic) slope from roughly −1.8 at low luminosities to roughly −2.8 at high luminosities. The empirical LFs can be reproduced by model LFs using an underlying cluster IMF with a Schechter type truncation around M∗ ≈ 2 × 105 M⊙ . This value of M⋆ can not be universal ...
Stories in the Stars
... of stars or galaxies. Star clusters are open or globular. Constellation. A pattern of stars that suggests the shape of some god, person, animal or object. Eclipse. Blocking of light from one body by another that passes in front of it. Eclipsing binary star. Binary star whose orbit around each other ...
... of stars or galaxies. Star clusters are open or globular. Constellation. A pattern of stars that suggests the shape of some god, person, animal or object. Eclipse. Blocking of light from one body by another that passes in front of it. Eclipsing binary star. Binary star whose orbit around each other ...
The Cosmic Perspective Our Galaxy
... b) Dust grains scatter blue light and let red light pass through, similar to the blue sky and red sunsets in our atmosphere. c) The blue color is due to the scattering of light by interstellar dust grains and the red color arises from hydrogen emissions. d) The blue light comes from young, hot st ...
... b) Dust grains scatter blue light and let red light pass through, similar to the blue sky and red sunsets in our atmosphere. c) The blue color is due to the scattering of light by interstellar dust grains and the red color arises from hydrogen emissions. d) The blue light comes from young, hot st ...
14. The Milky Way Galaxy: A Spiral in Space
... • The Galactic halo and globular clusters formed very early; the halo is essentially spherical. All the stars in the halo are very old, and there is no gas and dust. • The Galactic disk is where the youngest stars are, as well as star formation regions—emission nebulae, large clouds of gas and dust. ...
... • The Galactic halo and globular clusters formed very early; the halo is essentially spherical. All the stars in the halo are very old, and there is no gas and dust. • The Galactic disk is where the youngest stars are, as well as star formation regions—emission nebulae, large clouds of gas and dust. ...
Abundance Trends of Alpha and Fe
... in the “second-generation” halo stars that are observed today. The exceptions to the Ca overabundance trend at low metallicity may be more interesting than they were in the case of Ni. Ignoring the point of NGC 4833 from a relatively old study involving just two stars (Gratton & Ortolani 1989), the ...
... in the “second-generation” halo stars that are observed today. The exceptions to the Ca overabundance trend at low metallicity may be more interesting than they were in the case of Ni. Ignoring the point of NGC 4833 from a relatively old study involving just two stars (Gratton & Ortolani 1989), the ...
Major Themes of “ The First Stars ”
... address some of the most pressing questions about the galaxies of “First Light” – such as how metallicity, redshift, and environment interact in shaping the IMF. 3. Early indications are that the Pop III and early Pop II IMFs during the epoch of reionization preferred intermediate and massive stars, ...
... address some of the most pressing questions about the galaxies of “First Light” – such as how metallicity, redshift, and environment interact in shaping the IMF. 3. Early indications are that the Pop III and early Pop II IMFs during the epoch of reionization preferred intermediate and massive stars, ...
ASTR1102-002 Potentially useful facts and mathematical relations
... ASTR1102-002 Potentially useful facts and mathematical relations: A. ...
... ASTR1102-002 Potentially useful facts and mathematical relations: A. ...
STC-Scripting Guide for Celestia
... “What is a spectral class and what does it tell about a star and its properties?”. It might be useful for beginners, but if you already know what types of stars you want to create, you can skip them. Stars are obviously emitting light, otherwise we wouldn’t be able to see them, but they do not only ...
... “What is a spectral class and what does it tell about a star and its properties?”. It might be useful for beginners, but if you already know what types of stars you want to create, you can skip them. Stars are obviously emitting light, otherwise we wouldn’t be able to see them, but they do not only ...
A105 Stars and Galaxies
... The formation and evolution of these groups, which are very common in the Universe, are dominated by the gravitational pull of dark matter 4.3 Mpc or 14 million LY ...
... The formation and evolution of these groups, which are very common in the Universe, are dominated by the gravitational pull of dark matter 4.3 Mpc or 14 million LY ...
Variable stars in the globular cluster M 92
... For v13 (Nassau’s no. 14) he detected variations, but was unable to derive a period. He supposed, however, that if the light variations are real, and if they are periodic, the period should be close to 0.3 d. All 14 new RR Lyrae candidates he observed turned out to be constant, while three giants re ...
... For v13 (Nassau’s no. 14) he detected variations, but was unable to derive a period. He supposed, however, that if the light variations are real, and if they are periodic, the period should be close to 0.3 d. All 14 new RR Lyrae candidates he observed turned out to be constant, while three giants re ...
The Milky Way galaxy Contents Summary
... by galaxies that lie just below the top of the scale. The Sun lies in just such a galaxy, the Milky Way galaxy. Galaxies can usefully be considered to be made up of two components: a spheroid and a disc (Figure 1). The spheroid is made up of stars that move around in a disorganised way, rather like ...
... by galaxies that lie just below the top of the scale. The Sun lies in just such a galaxy, the Milky Way galaxy. Galaxies can usefully be considered to be made up of two components: a spheroid and a disc (Figure 1). The spheroid is made up of stars that move around in a disorganised way, rather like ...
TRIFFID photometry of globular cluster cores – I. Photometric
... implemented in the external IRAF package DIGIPHOTX, was used for all the photometric reductions. Photometry was first performed on archival HST/WFPC2 images of M15 in two filters – F439W which approximates to B, and F555W which approximates to V. These data were obtained under HST proposal GO 5324 ( ...
... implemented in the external IRAF package DIGIPHOTX, was used for all the photometric reductions. Photometry was first performed on archival HST/WFPC2 images of M15 in two filters – F439W which approximates to B, and F555W which approximates to V. These data were obtained under HST proposal GO 5324 ( ...
The Cosmos & the Bible - Access Research Network
... must go into woods to see only tree trunks all around. • To have a dark sky, universe must not be deep enough to see only star surfaces in all directions. • Thus the universe is of finite age, or finite size, or average star density = 0. ...
... must go into woods to see only tree trunks all around. • To have a dark sky, universe must not be deep enough to see only star surfaces in all directions. • Thus the universe is of finite age, or finite size, or average star density = 0. ...
Direct Detection of Galactic Halo Dark Matter
... predicted from the subdwarf star counts and a standard initial mass function is 1.3 ⫻ 10⫺5 MJ pc⫺3 (29), which is 10 times smaller than the value we calculate. This means that star formation in the early galaxy must have favored higher-mass stars that would evolve into the white dwarfs we are detect ...
... predicted from the subdwarf star counts and a standard initial mass function is 1.3 ⫻ 10⫺5 MJ pc⫺3 (29), which is 10 times smaller than the value we calculate. This means that star formation in the early galaxy must have favored higher-mass stars that would evolve into the white dwarfs we are detect ...
Article PDF - IOPscience
... wide range of colors (and include RR Lyrae variables), Fornax 4 is seen to have a red horizontal branch. Fornax 4 is D3 Gyr younger than the other Fornax globulars. Buonanno et al. draw attention to the fact that the colormagnitude diagram of Fornax 4 exhibits a strong resemblance to that of the ““ ...
... wide range of colors (and include RR Lyrae variables), Fornax 4 is seen to have a red horizontal branch. Fornax 4 is D3 Gyr younger than the other Fornax globulars. Buonanno et al. draw attention to the fact that the colormagnitude diagram of Fornax 4 exhibits a strong resemblance to that of the ““ ...
Spots on Ap Stars
... What are Coronal Holes? • Regions of the solar corona where the magnetic field lines diverge outward from the Sun • Develop in regions adjacent to areas of similar ...
... What are Coronal Holes? • Regions of the solar corona where the magnetic field lines diverge outward from the Sun • Develop in regions adjacent to areas of similar ...
Protogalaxies Encyclopedia of Astronomy & Astrophysics eaa.iop.org S G Djorgovski
... of galaxy formation would have different and equally legitimate definitions in mind. For example, an observer may mean ‘the first major burst of star formation in a progenitor of a present-day elliptical galaxy’, whereas a theorist may mean ‘the peak merging epoch of dark halos of the fragments whic ...
... of galaxy formation would have different and equally legitimate definitions in mind. For example, an observer may mean ‘the first major burst of star formation in a progenitor of a present-day elliptical galaxy’, whereas a theorist may mean ‘the peak merging epoch of dark halos of the fragments whic ...
Beasts of the Southern Wild: Discovery of nine Ultra Faint satellites
... Magellanic Clouds. Kroupa et al. (2005) developed this picture, adding more Milky Way satellites to the Great Magellanic family. The idea also receives support from the planar structures of satellites around M31 and other nearby galaxies (see e.g., Ibata et al. 2013; Tully et al. 2015). To explain t ...
... Magellanic Clouds. Kroupa et al. (2005) developed this picture, adding more Milky Way satellites to the Great Magellanic family. The idea also receives support from the planar structures of satellites around M31 and other nearby galaxies (see e.g., Ibata et al. 2013; Tully et al. 2015). To explain t ...
Presentazione di PowerPoint
... laboratory of N-body simulations. The basic collisionless collapse in a variety of N-body mechanisms have been modeled long ago by simulations [1]. To our knowledge, this is the first Chandrasekhar (1943), but are not understood under time that an analytically simple model constructed realistic cond ...
... laboratory of N-body simulations. The basic collisionless collapse in a variety of N-body mechanisms have been modeled long ago by simulations [1]. To our knowledge, this is the first Chandrasekhar (1943), but are not understood under time that an analytically simple model constructed realistic cond ...
Protogalaxies
... of galaxy formation would have different and equally legitimate definitions in mind. For example, an observer may mean ‘the first major burst of star formation in a progenitor of a present-day elliptical galaxy’, whereas a theorist may mean ‘the peak merging epoch of dark halos of the fragments whic ...
... of galaxy formation would have different and equally legitimate definitions in mind. For example, an observer may mean ‘the first major burst of star formation in a progenitor of a present-day elliptical galaxy’, whereas a theorist may mean ‘the peak merging epoch of dark halos of the fragments whic ...
ASTRONOMY AND ASTROPHYSICS How many low
... C, O, N, Al and Na on the RGB remains unexplained in many cases (see CBW98 for references). On the other hand, the extramixing process on the RGB has to destroy 3 He in more than 90% of the low-mass stars, and preserve it in the others, for the high (and standard) 3 He abundance observed in NGC 3242 ...
... C, O, N, Al and Na on the RGB remains unexplained in many cases (see CBW98 for references). On the other hand, the extramixing process on the RGB has to destroy 3 He in more than 90% of the low-mass stars, and preserve it in the others, for the high (and standard) 3 He abundance observed in NGC 3242 ...
Cosmic distance ladder
The cosmic distance ladder (also known as the extragalactic distance scale) is the succession of methods by which astronomers determine the distances to celestial objects. A real direct distance measurement of an astronomical object is possible only for those objects that are ""close enough"" (within about a thousand parsecs) to Earth. The techniques for determining distances to more distant objects are all based on various measured correlations between methods that work at close distances and methods that work at larger distances. Several methods rely on a standard candle, which is an astronomical object that has a known luminosity.The ladder analogy arises because no one technique can measure distances at all ranges encountered in astronomy. Instead, one method can be used to measure nearby distances, a second can be used to measure nearby to intermediate distances, and so on. Each rung of the ladder provides information that can be used to determine the distances at the next higher rung.