Astrophysical parameters of ten poorly studied open star clusters
... number of stars is not enough for an accepted fitting, the next larger area is included, and so on. In this way, different isochrones of solar metallicity (Z = 0.019) of different ages have been applied on the CMDs of each cluster, fitting the lower envelope of the points matching the main sequence ...
... number of stars is not enough for an accepted fitting, the next larger area is included, and so on. In this way, different isochrones of solar metallicity (Z = 0.019) of different ages have been applied on the CMDs of each cluster, fitting the lower envelope of the points matching the main sequence ...
White dwarf cooling sequences and cosmochronology
... than in the outer layers, thus resulting in a reduced specific heat at the central layers of the star, where the oxygen abundance can be as high as XO = 0.85 [20]. Crystallization: White dwarfs with log(L/L ) < −3 are expected to experience a first order phase transition, and their deep cores cryst ...
... than in the outer layers, thus resulting in a reduced specific heat at the central layers of the star, where the oxygen abundance can be as high as XO = 0.85 [20]. Crystallization: White dwarfs with log(L/L ) < −3 are expected to experience a first order phase transition, and their deep cores cryst ...
Image filtering
... In most cases (CCD images with local background subtracted), the noise spectrum can be considered as “white” on source scales: P () = cste ...
... In most cases (CCD images with local background subtracted), the noise spectrum can be considered as “white” on source scales: P () = cste ...
The Cosmological Distance Ladder
... new HST-ACS observations of Cepheids in galaxies with wellobserved Type Ia supernovae gives Ho = 73 +- 6 (Riess et al 2005) - but based on LMC, with 10% distance uncertainty inconsistencies with earlier results can be attributed to ...
... new HST-ACS observations of Cepheids in galaxies with wellobserved Type Ia supernovae gives Ho = 73 +- 6 (Riess et al 2005) - but based on LMC, with 10% distance uncertainty inconsistencies with earlier results can be attributed to ...
Conference Abstract Booklet here.
... light curves of Cepheid variables using the Fourier decomposition and principal component analysis methods. The theoretical Cepheid light curves are obtained using the full amplitude, nonlinear, convective hydrodynamical models for chemical compositions relative to Cepheids in the Galaxy (Y=0.28, Z= ...
... light curves of Cepheid variables using the Fourier decomposition and principal component analysis methods. The theoretical Cepheid light curves are obtained using the full amplitude, nonlinear, convective hydrodynamical models for chemical compositions relative to Cepheids in the Galaxy (Y=0.28, Z= ...
Manual Sattools
... minutes back and then press 'S'. With 'S' is meant shift + s, so capital S. Caution: do not go too far away from the previous position to prevent the mount from moving a lot and that takes time. Choose a sector of the sky from where most satellites are visible. For the Northern Hemisphere it is in t ...
... minutes back and then press 'S'. With 'S' is meant shift + s, so capital S. Caution: do not go too far away from the previous position to prevent the mount from moving a lot and that takes time. Choose a sector of the sky from where most satellites are visible. For the Northern Hemisphere it is in t ...
The Solar System Beyond The Planets
... satellites. The first satellite is on a near circular orbit at 49,500km from 2003 EL61 . Preliminary results (Brown et al., 2005c) show that the orbital period of the system is ∼49 days and the satellite brightness is 6% of 2003 EL61 (for reference, Pluto-Charon has an orbital period of 6.4 days and ...
... satellites. The first satellite is on a near circular orbit at 49,500km from 2003 EL61 . Preliminary results (Brown et al., 2005c) show that the orbital period of the system is ∼49 days and the satellite brightness is 6% of 2003 EL61 (for reference, Pluto-Charon has an orbital period of 6.4 days and ...
$doc.title
... 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 ...
Llama_2015_AJ_Transiting - St Andrews Research Repository
... the Sun appears relatively inactive, with only a few active regions present on the surface. At short wavelengths the Sun appears more active than when viewed in the optical. The EUV/FUV images reveal how relatively small sunspots in the optical correspond to very bright, large, extended regions at s ...
... the Sun appears relatively inactive, with only a few active regions present on the surface. At short wavelengths the Sun appears more active than when viewed in the optical. The EUV/FUV images reveal how relatively small sunspots in the optical correspond to very bright, large, extended regions at s ...
The Time Evolution of Faculae and Plage
... The Sun is a variable star and its irradiance has been measured and analyzed since the 1800’s. Early astronomers noted that the sun has a distinct solar cycle in which the total radiative output of the sun is highest at solar maximum, lowest at solar minimum, and there is an average variation in irr ...
... The Sun is a variable star and its irradiance has been measured and analyzed since the 1800’s. Early astronomers noted that the sun has a distinct solar cycle in which the total radiative output of the sun is highest at solar maximum, lowest at solar minimum, and there is an average variation in irr ...
Barium and europium abundances in cool dwarf stars and
... in June 1999. The data cover an approximate spectral range of 4000–7000 Å. The 1995 spectra were exposed to a 1024 × 1024 24µ CCD, and the resolving power was ∼ 40000. Starting from May 1997 a 2048 × 2048 15 µ CCD was employed at λ/∆λ ∼60000. Almost all the stars were observed at least twice with t ...
... in June 1999. The data cover an approximate spectral range of 4000–7000 Å. The 1995 spectra were exposed to a 1024 × 1024 24µ CCD, and the resolving power was ∼ 40000. Starting from May 1997 a 2048 × 2048 15 µ CCD was employed at λ/∆λ ∼60000. Almost all the stars were observed at least twice with t ...
The connection between stellar activity cycles and magnetic field
... chromospheric observations. Therefore, it is useful to study activity cycles with chromospheric data in conjunction with the ZDI technique. There are now numerous stars that have been characterised by ZDI that also have a chromospherically determined cycle period in the literature. While a number of ...
... chromospheric observations. Therefore, it is useful to study activity cycles with chromospheric data in conjunction with the ZDI technique. There are now numerous stars that have been characterised by ZDI that also have a chromospherically determined cycle period in the literature. While a number of ...
Sample syllabus 2 - Johns Hopkins Center for Talented Youth
... Course Description: When the sun runs out of fuel, will it explode in a giant supernova or fade out into a white dwarf? Does every galaxy revolve around a super-massive black hole? Will the universe continue to expand, or will it eventually collapse back upon itself in a reversal of the Big Bang? As ...
... Course Description: When the sun runs out of fuel, will it explode in a giant supernova or fade out into a white dwarf? Does every galaxy revolve around a super-massive black hole? Will the universe continue to expand, or will it eventually collapse back upon itself in a reversal of the Big Bang? As ...
lecture course
... gravitational lensing (both weak and strong) measurements. The existence of dark matter in a cosmological context comes from the consideration of a large number of datasets in conjunction with each other.for example, information comes from measurements of cosmic shear and the Lyman forest. Cosmologi ...
... gravitational lensing (both weak and strong) measurements. The existence of dark matter in a cosmological context comes from the consideration of a large number of datasets in conjunction with each other.for example, information comes from measurements of cosmic shear and the Lyman forest. Cosmologi ...
ASTRONOMY AND ASTROPHYSICS Barium and europium
... determine, as the r-process abundance of 138 Ba is very small and calculated as the difference of solar and s-process abundances. This is the difference of two large numbers and correspondingly has a very large uncertainty. They give the 138Ba isotope abundance for a pure r-process as 28% with uncer ...
... determine, as the r-process abundance of 138 Ba is very small and calculated as the difference of solar and s-process abundances. This is the difference of two large numbers and correspondingly has a very large uncertainty. They give the 138Ba isotope abundance for a pure r-process as 28% with uncer ...
Chapter 24
... than possessing a dense central nucleus, they often exhibit little internal structure of any kind. As with spirals, the stellar density increases sharply in the central nucleus. Denoted by the letter E, these systems are subdivided according to how elliptical they appear on the sky. The most circula ...
... than possessing a dense central nucleus, they often exhibit little internal structure of any kind. As with spirals, the stellar density increases sharply in the central nucleus. Denoted by the letter E, these systems are subdivided according to how elliptical they appear on the sky. The most circula ...
12C13C1414N21312C/13C3he43He/4He Sub-surface
... occurrence and properties of these convection zones as function of the stellar parameters. We then confront our results with observations of OB stars. A stellar evolution code is used to compute a grid of massive star models at different metallicities. In these models, the mixing length theory is us ...
... occurrence and properties of these convection zones as function of the stellar parameters. We then confront our results with observations of OB stars. A stellar evolution code is used to compute a grid of massive star models at different metallicities. In these models, the mixing length theory is us ...
MASSIVE CLOSE BINARIES
... that Case B is the more frequent class of interacting binaries. Compared to Case B, it is trivial to understand that Case A components have smaller final masses whereas it is obvious that Case C (and non-interacting) binaries are similar to single stars. Equation 1 decides upon the mass loss during ...
... that Case B is the more frequent class of interacting binaries. Compared to Case B, it is trivial to understand that Case A components have smaller final masses whereas it is obvious that Case C (and non-interacting) binaries are similar to single stars. Equation 1 decides upon the mass loss during ...