Where stars form: inside-out growth and coherent star formation from
... 2676 galaxies enabling a division into subsamples based on stellar mass and star formation rate. By creating deep stacked Hα images, we reach surface brightness limits of 1 × 10−18 erg s−1 cm−2 arcsec−2 , allowing us to map the distribution of ionized gas out to greater than 10 kpc for typical L∗ ga ...
... 2676 galaxies enabling a division into subsamples based on stellar mass and star formation rate. By creating deep stacked Hα images, we reach surface brightness limits of 1 × 10−18 erg s−1 cm−2 arcsec−2 , allowing us to map the distribution of ionized gas out to greater than 10 kpc for typical L∗ ga ...
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... companion to the star 51 Pegasi, circling the sun-like star at a distance of a = 0.05 AU, one hundredth of the distance between Jupiter and the Sun. Just months later, Jovian and super-Jovian mass companions were announced by Marcy & Butler (1996a) around 70 Virginis (a = 0.43 AU), Butler & Marcy (1 ...
... companion to the star 51 Pegasi, circling the sun-like star at a distance of a = 0.05 AU, one hundredth of the distance between Jupiter and the Sun. Just months later, Jovian and super-Jovian mass companions were announced by Marcy & Butler (1996a) around 70 Virginis (a = 0.43 AU), Butler & Marcy (1 ...
Document
... Step 3. Choose a “Standard Plate” (typically your first observation) and transform all other images into it using the method of least-squares and simultaneously solve for Parallax and proper motion Xtrans = a*X+b*Y+c ...
... Step 3. Choose a “Standard Plate” (typically your first observation) and transform all other images into it using the method of least-squares and simultaneously solve for Parallax and proper motion Xtrans = a*X+b*Y+c ...
Towards the understanding of the deepest layers of solar
... I would like to start by thanking both my supervisors, Dra. Margarida Cunha and Prof. Dr. Jørgen Christensen-Dalsgaard, without whom the realization of this thesis would not have been possible. I would like to give a very special thank to Prof. Dr. Jørgen ChristensenDalsgaard for his hospitality and ...
... I would like to start by thanking both my supervisors, Dra. Margarida Cunha and Prof. Dr. Jørgen Christensen-Dalsgaard, without whom the realization of this thesis would not have been possible. I would like to give a very special thank to Prof. Dr. Jørgen ChristensenDalsgaard for his hospitality and ...
The Ages of Stars
... significantly to the observations available to address these problems, and the quality of the models has kept pace. The problems are not solved, but we probably have a better understanding of the limitations. Also, as I note at the end, I expect major advances in this area over the next few years. I ...
... significantly to the observations available to address these problems, and the quality of the models has kept pace. The problems are not solved, but we probably have a better understanding of the limitations. Also, as I note at the end, I expect major advances in this area over the next few years. I ...
New brown dwarfs and giant planets
... ~50% trig/50% photo parallaxes Proper motions for all (U, V, W) velocities ...
... ~50% trig/50% photo parallaxes Proper motions for all (U, V, W) velocities ...
The spectroscopic Hertzsprung
... et al. 2011). It is interesting to consider both types of evolution in the HR and sHR diagram. Both situations can lead to stars that are overluminous, i.e. stars that have a luminosity larger than the luminosity of a single star of comparable mass and evolutionary state. Kippenhahn & Weigert (1990) ...
... et al. 2011). It is interesting to consider both types of evolution in the HR and sHR diagram. Both situations can lead to stars that are overluminous, i.e. stars that have a luminosity larger than the luminosity of a single star of comparable mass and evolutionary state. Kippenhahn & Weigert (1990) ...
November Celestial Calendar by Dave Mitsky All times are UT
... and November 12 respectively. These streams form part of the complex associated with Comet 2P/Encke. The Full Moon severely compromises the peak of the Leonid meteor shower on the morning of November 17. Leonid meteors are debris from the periodic comet 55P/TempelTuttle. Because of their high speed ...
... and November 12 respectively. These streams form part of the complex associated with Comet 2P/Encke. The Full Moon severely compromises the peak of the Leonid meteor shower on the morning of November 17. Leonid meteors are debris from the periodic comet 55P/TempelTuttle. Because of their high speed ...
Galactic Stellar and Substellar Initial Mass Function Invited Review Gilles Chabrier
... enables us to derive only an upper limit for the spheroid mass density and IMF. Within all the uncertainties, the latter is found to be similar to the one derived for globular clusters and is well represented also by a lognormal form with a characteristic mass slightly larger than for the disk, mc ∼ ...
... enables us to derive only an upper limit for the spheroid mass density and IMF. Within all the uncertainties, the latter is found to be similar to the one derived for globular clusters and is well represented also by a lognormal form with a characteristic mass slightly larger than for the disk, mc ∼ ...
I. Constellations
... ____stars____ named after ____an animal____, ____a person____ or ___ an object ____. B. In modern astronomy, a constellation is defined as a specific ____area____ of the sky as determined by the International Astronomical Union (IAU). C. The celestial sphere is divided into __88___ contiguous region ...
... ____stars____ named after ____an animal____, ____a person____ or ___ an object ____. B. In modern astronomy, a constellation is defined as a specific ____area____ of the sky as determined by the International Astronomical Union (IAU). C. The celestial sphere is divided into __88___ contiguous region ...
On the nature of sn stars. I. A detailed abundance study
... among sn stars (see e.g. Table 7 in Abt 1979), which is also supported by their low projected rotational velocity (Mermilliod 1983). One of the aims of this work is to study the possibility that all sn stars were in fact related to CP stars and search for common features in their abundance values. A ...
... among sn stars (see e.g. Table 7 in Abt 1979), which is also supported by their low projected rotational velocity (Mermilliod 1983). One of the aims of this work is to study the possibility that all sn stars were in fact related to CP stars and search for common features in their abundance values. A ...
Ages of Young Stars
... (l) Cargile and James (2010), (m) Naylor et al. (2009), (n) derived by E. Mamajek using data from Hauck and Mermilliod (1998) and isochrones from Bertelli et al. (2009), (o) Ventura et al. (1998). ally negligible) and, presented separately, the systematic absolute age uncertainty estimated by Burke ...
... (l) Cargile and James (2010), (m) Naylor et al. (2009), (n) derived by E. Mamajek using data from Hauck and Mermilliod (1998) and isochrones from Bertelli et al. (2009), (o) Ventura et al. (1998). ally negligible) and, presented separately, the systematic absolute age uncertainty estimated by Burke ...
Ages of young stars
... individual objects. A reliable age scale is established above 20 Myr from measurement of the Lithium Depletion Boundary (LDB) in young clusters, and consistency is shown between these ages and those from the upper main sequence and the main sequence turn-off – if modest core convection and rotation ...
... individual objects. A reliable age scale is established above 20 Myr from measurement of the Lithium Depletion Boundary (LDB) in young clusters, and consistency is shown between these ages and those from the upper main sequence and the main sequence turn-off – if modest core convection and rotation ...
The Kuiper Belt Explored by Serendipitous Stellar Occultations
... The characteristic scale of the Fresnel diffraction effect (i.e., roughly speaking, the broadening of the object shadow) is the so-called Fresnel scale Fs = (λD/2) (Warner, 1988). [Note that some authors give different definitions for the Fresnel scale: (λD/2π) , (λD) , or (λD)/2 .] The Fresnel scal ...
... The characteristic scale of the Fresnel diffraction effect (i.e., roughly speaking, the broadening of the object shadow) is the so-called Fresnel scale Fs = (λD/2) (Warner, 1988). [Note that some authors give different definitions for the Fresnel scale: (λD/2π) , (λD) , or (λD)/2 .] The Fresnel scal ...
observations of white dwarfs in the solar neighborhood
... and June 22. We used the SITE 2048 2048 CCD and the 600 line mm1 grating to obtain a spectral range of 4210– 7560 Å with substantial vignetting toward the ends of this range. The 100 slit gave 3.2 Å spectral resolution (FWHM). The main observing program was focused on accurate radial velocitie ...
... and June 22. We used the SITE 2048 2048 CCD and the 600 line mm1 grating to obtain a spectral range of 4210– 7560 Å with substantial vignetting toward the ends of this range. The 100 slit gave 3.2 Å spectral resolution (FWHM). The main observing program was focused on accurate radial velocitie ...
Differential rotation on both components of the pre-main
... minimal due to the fact that for most of the orbit (approximately two-thirds) the profiles of the two stars are cleanly separated in velocity space. The DoTS code has been extensively tested on binary systems with more entangled spectra than HD 155555, for example the contact system AE Phe was mappe ...
... minimal due to the fact that for most of the orbit (approximately two-thirds) the profiles of the two stars are cleanly separated in velocity space. The DoTS code has been extensively tested on binary systems with more entangled spectra than HD 155555, for example the contact system AE Phe was mappe ...
Astrometric accuracy during the past 2000 years
... apparently not always in the other diagrams: it shows catalogue errors of single stars rather than errors of single observations and it only shows some of the most accurate catalogues of the given time. To be precise: I am plotting the median external standard error per star in the catalogues, if av ...
... apparently not always in the other diagrams: it shows catalogue errors of single stars rather than errors of single observations and it only shows some of the most accurate catalogues of the given time. To be precise: I am plotting the median external standard error per star in the catalogues, if av ...
Type Ia Supernovae
... after Tycho made his paradigm changing discovery using SN 1572, and some 60 years after supernovae had been identified as distant dying stars, two teams changed the view of the world again using supernovae. The found that the Universe was accelerating in its expansion, a conclusion that could most e ...
... after Tycho made his paradigm changing discovery using SN 1572, and some 60 years after supernovae had been identified as distant dying stars, two teams changed the view of the world again using supernovae. The found that the Universe was accelerating in its expansion, a conclusion that could most e ...
Lyra
Lyra (/ˈlaɪərə/; Latin for lyre, from Greek λύρα) is a small constellation. It is one of 48 listed by the 2nd century astronomer Ptolemy, and is one of the 88 constellations recognized by the International Astronomical Union. Lyra was often represented on star maps as a vulture or an eagle carrying a lyre, and hence sometimes referred to as Aquila Cadens or Vultur Cadens. Beginning at the north, Lyra is bordered by Draco, Hercules, Vulpecula, and Cygnus. Lyra is visible from the northern hemisphere from spring through autumn, and nearly overhead, in temperate latitudes, during the summer months. From the southern hemisphere, it is visible low in the northern sky during the winter months.The lucida or brightest star—and one of the brightest stars in the sky—is the white main sequence star Vega, a corner of the Summer Triangle. Beta Lyrae is the prototype of a class of stars known as Beta Lyrae variables, binary stars so close to each other that they become egg-shaped and material flows from one to the other. Epsilon Lyrae, known informally as the Double Double, is a complex multiple star system. Lyra also hosts the Ring Nebula, the second-discovered and best-known planetary nebula.