Entropy Production of Main-Sequence Stars
... the same distance from the Sun; (4) the HR diagram of clusters must be well approximated by theoretical isochrones plotted according to the model (the Padova database of evolutionary tracks and isochrones web-site: http://pleiadi.oapd.inaf.it/) [29,30] using the values of age and metallicity from th ...
... the same distance from the Sun; (4) the HR diagram of clusters must be well approximated by theoretical isochrones plotted according to the model (the Padova database of evolutionary tracks and isochrones web-site: http://pleiadi.oapd.inaf.it/) [29,30] using the values of age and metallicity from th ...
Basic principles of celestial navigation
... with its center at O and its polar axis coincident with the Earth’s rotational axis. The position of each celestial object is represented by the point on the celestial sphere at which a line to it from O intersects this sphere. Inasmuch as the distances to all stars, planets, and the Sun are much gr ...
... with its center at O and its polar axis coincident with the Earth’s rotational axis. The position of each celestial object is represented by the point on the celestial sphere at which a line to it from O intersects this sphere. Inasmuch as the distances to all stars, planets, and the Sun are much gr ...
Basic principles of celestial navigation
... with its center at O and its polar axis coincident with the Earth’s rotational axis. The position of each celestial object is represented by the point on the celestial sphere at which a line to it from O intersects this sphere. Inasmuch as the distances to all stars, planets, and the Sun are much gr ...
... with its center at O and its polar axis coincident with the Earth’s rotational axis. The position of each celestial object is represented by the point on the celestial sphere at which a line to it from O intersects this sphere. Inasmuch as the distances to all stars, planets, and the Sun are much gr ...
Ground-Based Astrometry 2010-2020
... complete with three-dimensional velocity vectors. This would yield the distance to the Galactic center (R0 ), the rotation speed of the LSR (Θ0 ), the form of the rotation curve, and the kinematic effects of spiral structure. In conjunction with the astrometrically-determined proper motions of Milky ...
... complete with three-dimensional velocity vectors. This would yield the distance to the Galactic center (R0 ), the rotation speed of the LSR (Θ0 ), the form of the rotation curve, and the kinematic effects of spiral structure. In conjunction with the astrometrically-determined proper motions of Milky ...
CH12.Ast1001.F13.EDS
... clusters show that a star becomes larger, redder, and more luminous after its time on the main sequence is over. ...
... clusters show that a star becomes larger, redder, and more luminous after its time on the main sequence is over. ...
Description of Pictures In the Dome
... Centaurus A (also known as NGC 5128) is a lenticular galaxy about 11 million light-years away in the constellation Centaurus. It is one of the closest radio galaxies to Earth, so its active galactic nucleus has been extensively studied by professional astronomers. The galaxy is also the fifth bright ...
... Centaurus A (also known as NGC 5128) is a lenticular galaxy about 11 million light-years away in the constellation Centaurus. It is one of the closest radio galaxies to Earth, so its active galactic nucleus has been extensively studied by professional astronomers. The galaxy is also the fifth bright ...
The HERMES GALAH survey: overview
... ages up to about 10 Gyr cover a broad abundance range, with [Fe/H] values between about 0.7 to +0.5 and only a weak trend of increasing abundance with decreasing age. The current belief is that the most metal-rich thin disk stars near the sun did not form near the sun but rather formed in the more m ...
... ages up to about 10 Gyr cover a broad abundance range, with [Fe/H] values between about 0.7 to +0.5 and only a weak trend of increasing abundance with decreasing age. The current belief is that the most metal-rich thin disk stars near the sun did not form near the sun but rather formed in the more m ...
Cepheid
... they change by perhaps 10% in diameter The periods range from a few days to several hundred days (but any given Cepheid has a fixed, well-defined period). ...
... they change by perhaps 10% in diameter The periods range from a few days to several hundred days (but any given Cepheid has a fixed, well-defined period). ...
P1 topic 3 - WordPress.com
... (iii) One theory of the origin of the Universe predicted that there should be cosmic background radiation with a wavelength of about 1 mm. Explain why scientists had to wait until the development of space flight before they could study this radiation in detail. ...
... (iii) One theory of the origin of the Universe predicted that there should be cosmic background radiation with a wavelength of about 1 mm. Explain why scientists had to wait until the development of space flight before they could study this radiation in detail. ...
Galactic Archaeology: Current Surveys
... 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 signal-to-noise spectra, an estimate of the relative abundance of the ‘alpha-ele ...
... 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 signal-to-noise spectra, an estimate of the relative abundance of the ‘alpha-ele ...
Neon abundances - UCL Astrophysics Group
... 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 superficially normal group. Some of the other stars in the two samples w ...
... 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 superficially normal group. Some of the other stars in the two samples w ...
Galaxy Structure
... the Keplerian law at a distance of 50 kpc. However, measurements indicate that the rotation curve of the Milky Way essentially stays flat. It actually may even still increase at the distance of the MAGELLANIC CLOUDS and the MAGELLANIC STREAM. Murai (1997) has clarified, on the basis of recent observ ...
... the Keplerian law at a distance of 50 kpc. However, measurements indicate that the rotation curve of the Milky Way essentially stays flat. It actually may even still increase at the distance of the MAGELLANIC CLOUDS and the MAGELLANIC STREAM. Murai (1997) has clarified, on the basis of recent observ ...
copyright 2002 scientific american, inc.
... The two categories differ spectroscopically, with short bursts having relatively more high-energy gamma rays than long bursts do. The January 1999 burst emitted gamma rays for a minute and a half. Arguably the most important result from BATSE concerned the distribution of the bursts. They occur isot ...
... The two categories differ spectroscopically, with short bursts having relatively more high-energy gamma rays than long bursts do. The January 1999 burst emitted gamma rays for a minute and a half. Arguably the most important result from BATSE concerned the distribution of the bursts. They occur isot ...
Today in Astronomy 102: black hole observations, v.2
... The center of the Milky Way is obscured by dust; it cannot be seen at visible through longer X-ray wavelengths. It is bright at infrared and radio wavelengths, and hard (shortwavelength) X rays, which are transmitted through the dust. The name Sagittarius A indicates that it’s the brightest radi ...
... The center of the Milky Way is obscured by dust; it cannot be seen at visible through longer X-ray wavelengths. It is bright at infrared and radio wavelengths, and hard (shortwavelength) X rays, which are transmitted through the dust. The name Sagittarius A indicates that it’s the brightest radi ...
Estudio de Cúmulos de Galaxias en el Sloan Digital Sky Survey
... Galaxy mergers & morphology The model distinguish two type of mergers: • major mergers: stellar disks -> stellar bulge ...
... Galaxy mergers & morphology The model distinguish two type of mergers: • major mergers: stellar disks -> stellar bulge ...
THE N/O RATIO IN EARLY B-TYPE MAIN SEQUENCE STARS AS
... logC , logN , and logO for MS B-stars found in Ref. 14, together with recent estimates of the abundances of C, N, and O for the sun [15,16]. The latter were obtained using nonstationary hydrodynamic 3D models of the solar atmosphere. We note that the elemental abundances here and in the ...
... logC , logN , and logO for MS B-stars found in Ref. 14, together with recent estimates of the abundances of C, N, and O for the sun [15,16]. The latter were obtained using nonstationary hydrodynamic 3D models of the solar atmosphere. We note that the elemental abundances here and in the ...
No. 2 - Society for Astronomical Sciences
... photometer in B and V bands, and the Tenagra 0.8-m telescope and CCD, on a sample of stars which had been observed by ROTSE and preliminarily categorized as RR Lyra variables. (Note that this is similar in concept to the study that Jerry Horne described at SAS-2010). Their findings (which are also s ...
... photometer in B and V bands, and the Tenagra 0.8-m telescope and CCD, on a sample of stars which had been observed by ROTSE and preliminarily categorized as RR Lyra variables. (Note that this is similar in concept to the study that Jerry Horne described at SAS-2010). Their findings (which are also s ...
How the Sun Shines - Department of Earth and Planetary Sciences
... energy, thus increases the possible limit of the duration of life on this planet, and allows the time claimed by the geologist and biologist for the process of evolution. The discovery of radioactivity opened up the possibility that nuclear energy might be the origin of solar radiation. This develop ...
... energy, thus increases the possible limit of the duration of life on this planet, and allows the time claimed by the geologist and biologist for the process of evolution. The discovery of radioactivity opened up the possibility that nuclear energy might be the origin of solar radiation. This develop ...
IK Pegasi
IK Pegasi (or HR 8210) is a binary star system in the constellation Pegasus. It is just luminous enough to be seen with the unaided eye, at a distance of about 150 light years from the Solar System.The primary (IK Pegasi A) is an A-type main-sequence star that displays minor pulsations in luminosity. It is categorized as a Delta Scuti variable star and it has a periodic cycle of luminosity variation that repeats itself about 22.9 times per day. Its companion (IK Pegasi B) is a massive white dwarf—a star that has evolved past the main sequence and is no longer generating energy through nuclear fusion. They orbit each other every 21.7 days with an average separation of about 31 million kilometres, or 19 million miles, or 0.21 astronomical units (AU). This is smaller than the orbit of Mercury around the Sun.IK Pegasi B is the nearest known supernova progenitor candidate. When the primary begins to evolve into a red giant, it is expected to grow to a radius where the white dwarf can accrete matter from the expanded gaseous envelope. When the white dwarf approaches the Chandrasekhar limit of 1.44 solar masses (M☉), it may explode as a Type Ia supernova.