High precision effective temperatures for 181 F-
... between A0 and K3 by using IRFM and achieved an accuracy of 0.9%. DB98 derived Teff for 537 dwarfs and giants by the empirical method of surface brightness and Johnson broadband (V − K) color, the accuracy claimed is ±1%. Whenever 2 or 3 estimates were available for a given star, we averaged them wi ...
... between A0 and K3 by using IRFM and achieved an accuracy of 0.9%. DB98 derived Teff for 537 dwarfs and giants by the empirical method of surface brightness and Johnson broadband (V − K) color, the accuracy claimed is ±1%. Whenever 2 or 3 estimates were available for a given star, we averaged them wi ...
Which planet has never been orbited or flown past by a
... Wandersee, J. H., Mintzes, J. J., & Novak, J. D. 1994, Research on Alternative Conceptions in Science, In Handbook of Research on Science Teaching and Learning, D. L. Gabel (Editor), New York: MacMillan Publishing, 177. Janke, D. L., & Pella, M. O. 1972, Earth Science Concept List for Grades K–12 Cu ...
... Wandersee, J. H., Mintzes, J. J., & Novak, J. D. 1994, Research on Alternative Conceptions in Science, In Handbook of Research on Science Teaching and Learning, D. L. Gabel (Editor), New York: MacMillan Publishing, 177. Janke, D. L., & Pella, M. O. 1972, Earth Science Concept List for Grades K–12 Cu ...
Discovery of Kilohertz Quasi-periodic Oscillations from 4U 1820
... highest QPO frequency we observe is identified with the marginally stable orbit in the accretion disk, the neutron star mass may be 12 MJ, 35%–50% more massive than usually assumed. This may have consequences for the current evolutionary scenarios for this source and also for the debate about the ev ...
... highest QPO frequency we observe is identified with the marginally stable orbit in the accretion disk, the neutron star mass may be 12 MJ, 35%–50% more massive than usually assumed. This may have consequences for the current evolutionary scenarios for this source and also for the debate about the ev ...
Stars as thermonuclear reactors: their fuels and ashes
... The sun and other “main-sequence” stars (burning hydrogen in their core quiescently) evolve very slowly by adjusting their central temperature such that the average thermal energy of a nucleus is small compared to the Coulomb repulsion an ion-ion pair encounters. This is how stars can live long for ...
... The sun and other “main-sequence” stars (burning hydrogen in their core quiescently) evolve very slowly by adjusting their central temperature such that the average thermal energy of a nucleus is small compared to the Coulomb repulsion an ion-ion pair encounters. This is how stars can live long for ...
Heavy Element Abundances in Late-B and Early
... important atmospheric processes (i.e., magnetic fields, convective motions, stellar winds, and mass loss) are also yet to be understood but are considered to be contributing factors to the formulation of the observed spectral features. While the IUE high-dispersion spectra will not be able to provid ...
... important atmospheric processes (i.e., magnetic fields, convective motions, stellar winds, and mass loss) are also yet to be understood but are considered to be contributing factors to the formulation of the observed spectral features. While the IUE high-dispersion spectra will not be able to provid ...
Energetic neutral atoms around HD 209458b
... asymmetry in attenuation over time, making attenuation post-transit higher than pre-transit for an equal time shift. The curve of attenuation over time is in agreement with the observations by Vidal-Madjar et al. (2003), and is also similar to their modeled attenuation curve. We find it difficult to ...
... asymmetry in attenuation over time, making attenuation post-transit higher than pre-transit for an equal time shift. The curve of attenuation over time is in agreement with the observations by Vidal-Madjar et al. (2003), and is also similar to their modeled attenuation curve. We find it difficult to ...
Parent stars of extrasolar planets III: ρ1 Cancri Revisited
... α Cen B from an analysis of its Hα profile. While this is 75 K less than their Fe-line based estimate, it is exactly equal to our estimate. This shows that discrepancies between Hα-based and Fe-based Teff estimates are not restricted to ρ1 Cnc. The uncertainties in the atmosphere parameters were est ...
... α Cen B from an analysis of its Hα profile. While this is 75 K less than their Fe-line based estimate, it is exactly equal to our estimate. This shows that discrepancies between Hα-based and Fe-based Teff estimates are not restricted to ρ1 Cnc. The uncertainties in the atmosphere parameters were est ...
The secular evolution of the Kuiper belt after a close stellar encounter
... The Kuiper belt bears the signature it the early evolution of the Solar System, and a contains records of the end-state of the accretion processes occurred in that region. Therefore, the knowledge of the history of the Kuiper belt objects (KBOs) is relevant to be able to develop a full consensus of ...
... The Kuiper belt bears the signature it the early evolution of the Solar System, and a contains records of the end-state of the accretion processes occurred in that region. Therefore, the knowledge of the history of the Kuiper belt objects (KBOs) is relevant to be able to develop a full consensus of ...
Stars: Intro & Classification Astronomy 1 — Elementary Astronomy LA Mission College
... LA Mission College Spring F2015 ...
... LA Mission College Spring F2015 ...
Astronomy 112: The Physics of Stars Class 1 Notes
... Although this technique has been understood since antiquity, our ability to actually use it depends on being able to measure very small angular shifts. The nearest star to us is Proxima Centauri, which has a parallax of 0.88” – to put this in perspective, this corresponds to the size of a quarter at ...
... Although this technique has been understood since antiquity, our ability to actually use it depends on being able to measure very small angular shifts. The nearest star to us is Proxima Centauri, which has a parallax of 0.88” – to put this in perspective, this corresponds to the size of a quarter at ...
The Central Star Candidate of the Planetary Nebula Sh2
... The Central Star Candidate of the Planetary Nebula Sh2-71 of five most suitable stars in each image. Sky annulus was placed between two and three FWHM from the stellar centres. This photometric configuration was found to maximize the signal to noise ratios of the differential magnitudes. We were on ...
... The Central Star Candidate of the Planetary Nebula Sh2-71 of five most suitable stars in each image. Sky annulus was placed between two and three FWHM from the stellar centres. This photometric configuration was found to maximize the signal to noise ratios of the differential magnitudes. We were on ...
Sample pages 1 PDF
... we already discussed in the context of galaxies and galaxy clusters. Recent observational results have shown that the mean density of dark matter dominates over that of baryonic matter also on cosmic scales. Even more surprising than the existence of dark matter is the discovery that about 70 % of t ...
... we already discussed in the context of galaxies and galaxy clusters. Recent observational results have shown that the mean density of dark matter dominates over that of baryonic matter also on cosmic scales. Even more surprising than the existence of dark matter is the discovery that about 70 % of t ...
BD−21 3873: another yellow-symbiotic barium star
... to the binary barium and CH stars which are also s-process enriched. These binary systems, which exhibit overabundances of the heavy elements, owe their abundance peculiarities to mass transfer from thermally-pulsing asymptotic giant branch stars, which have since evolved to become white-dwarf compa ...
... to the binary barium and CH stars which are also s-process enriched. These binary systems, which exhibit overabundances of the heavy elements, owe their abundance peculiarities to mass transfer from thermally-pulsing asymptotic giant branch stars, which have since evolved to become white-dwarf compa ...
Astronomical Facts `n Stuff
... The fading fireball of a gamma-ray burst — a sudden burst of gamma rays from deep space — that is observable in less energetic wavelengths, such as X-ray, optical, and radio. After an initial explosion, an expanding gamma-ray burst slows and sweeps up surrounding material, generating the afterglow, ...
... The fading fireball of a gamma-ray burst — a sudden burst of gamma rays from deep space — that is observable in less energetic wavelengths, such as X-ray, optical, and radio. After an initial explosion, an expanding gamma-ray burst slows and sweeps up surrounding material, generating the afterglow, ...
A Spitzer mid-infrared spectral survey of mass
... little dust formation (Zijlstra et al. 2004). The mass-loss process is important for three reasons. First, it determines the mass distribution of stellar remnants, including, e.g. the lower mass limit of type II supernovae progenitors (Zijlstra 2004). Secondly, the physics and interplay of stellar p ...
... little dust formation (Zijlstra et al. 2004). The mass-loss process is important for three reasons. First, it determines the mass distribution of stellar remnants, including, e.g. the lower mass limit of type II supernovae progenitors (Zijlstra 2004). Secondly, the physics and interplay of stellar p ...
13 Galaxies - Journigan-wiki
... Spiral disks rotate rapidly when compared to elliptical halos. However, halos and bulges in spiral galaxies rotate much more slowly. Thus astronomers believe that more than a galaxy’s rotation determines its type. ...
... Spiral disks rotate rapidly when compared to elliptical halos. However, halos and bulges in spiral galaxies rotate much more slowly. Thus astronomers believe that more than a galaxy’s rotation determines its type. ...
Star formation
Star formation is the process by which dense regions within molecular clouds in interstellar space, sometimes referred to as ""stellar nurseries"" or ""star-forming regions"", collapse to form stars. As a branch of astronomy, star formation includes the study of the interstellar medium (ISM) and giant molecular clouds (GMC) as precursors to the star formation process, and the study of protostars and young stellar objects as its immediate products. It is closely related to planet formation, another branch of astronomy. Star formation theory, as well as accounting for the formation of a single star, must also account for the statistics of binary stars and the initial mass function.In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.