The Oort Cloud
... molecular clouds and tidal forces. A giant molecular-cloud is by far more massive than the Sun. It is an accumulation of cold hydrogen that is the birthplace of stars and solar systems. These are infrequently encountered, about every 300-500 million years, but when they are encountered, they can vio ...
... molecular clouds and tidal forces. A giant molecular-cloud is by far more massive than the Sun. It is an accumulation of cold hydrogen that is the birthplace of stars and solar systems. These are infrequently encountered, about every 300-500 million years, but when they are encountered, they can vio ...
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... cooler white dwarf sample of Bergeron, Saffer & Liebert (1992), then the hydrogen layer mass must be considerably less than 1 0 - 4 M * . In this context, Mh < 1 0 - 6 M * suffices, and this is not surprising, given that the two major channels of spectral evolution will have DA stars through the 30 ...
... cooler white dwarf sample of Bergeron, Saffer & Liebert (1992), then the hydrogen layer mass must be considerably less than 1 0 - 4 M * . In this context, Mh < 1 0 - 6 M * suffices, and this is not surprising, given that the two major channels of spectral evolution will have DA stars through the 30 ...
Astronomy Astrophysics NGC 7419 as a template for red supergiant clusters &
... spectroscopy around the Hα line for most of the candidate Be stars, confirming their nature. A second peculiarity of NGC 7419 is the presence of five red supergiants (RSGs) as confirmed radial velocity members of the cluster (Beauchamp et al. 1994). Until recently, this was the highest number of RSG ...
... spectroscopy around the Hα line for most of the candidate Be stars, confirming their nature. A second peculiarity of NGC 7419 is the presence of five red supergiants (RSGs) as confirmed radial velocity members of the cluster (Beauchamp et al. 1994). Until recently, this was the highest number of RSG ...
variable star type designations in vsx
... binaries, the subtypes indicate which kind of behavior the binary displays, as in X-ray bursts (XB), large amplitude outbursts also in the visual (XN), reflection effect (XR) or it may also indicate something about the object's nature, as in a compact object which is a pulsar (XP). Finally, the subt ...
... binaries, the subtypes indicate which kind of behavior the binary displays, as in X-ray bursts (XB), large amplitude outbursts also in the visual (XN), reflection effect (XR) or it may also indicate something about the object's nature, as in a compact object which is a pulsar (XP). Finally, the subt ...
sections 19-22 instructor notes
... local deviations from circular motion, to any errors in the adopted LSR velocity of the Sun, and even to slight errors in l0. Crampton et al. (MNRAS, 176, 683, 1976) used the technique to obtain a value of R0 = 8.4 ±1.0 kpc for B stars, not an unreasonable result. Interesting results have been deriv ...
... local deviations from circular motion, to any errors in the adopted LSR velocity of the Sun, and even to slight errors in l0. Crampton et al. (MNRAS, 176, 683, 1976) used the technique to obtain a value of R0 = 8.4 ±1.0 kpc for B stars, not an unreasonable result. Interesting results have been deriv ...
sections 19-22 instructor notes
... local deviations from circular motion, to any errors in the adopted LSR velocity of the Sun, and even to slight errors in l0. Crampton et al. (MNRAS, 176, 683, 1976) used the technique to obtain a value of R0 = 8.4 ±1.0 kpc for B stars, not an unreasonable result. Interesting results have been deriv ...
... local deviations from circular motion, to any errors in the adopted LSR velocity of the Sun, and even to slight errors in l0. Crampton et al. (MNRAS, 176, 683, 1976) used the technique to obtain a value of R0 = 8.4 ±1.0 kpc for B stars, not an unreasonable result. Interesting results have been deriv ...
Extended Infrared Emission from LIRGs
... The Sample is drawn from the Great Observatory Allsky LIRG Survey (GOALS; Armus et al. 2009) of 202 systems (181 of which are LIRGs) All systems are observed with all four Spitzer/IRS modules (5-37μm) Apply an upper limit on distance (<85 Mpc) in order for the IRS slit size to correspond to a projec ...
... The Sample is drawn from the Great Observatory Allsky LIRG Survey (GOALS; Armus et al. 2009) of 202 systems (181 of which are LIRGs) All systems are observed with all four Spitzer/IRS modules (5-37μm) Apply an upper limit on distance (<85 Mpc) in order for the IRS slit size to correspond to a projec ...
My Constellation
... Õ M7 is an open cluster. It's about 800 light years away. Õ M80 (NGC 6093) is a rather faint, very compact, globular cluster in the vicinity of Antares, between this star and beta Scorpii, and more narrowly speaking, nearly midpoint between two 8th-magnitude stars (which are the brightest stars of t ...
... Õ M7 is an open cluster. It's about 800 light years away. Õ M80 (NGC 6093) is a rather faint, very compact, globular cluster in the vicinity of Antares, between this star and beta Scorpii, and more narrowly speaking, nearly midpoint between two 8th-magnitude stars (which are the brightest stars of t ...
Astronomy Astrophysics Spectral energy distributions of an AKARI-SDSS-GALEX sample of galaxies
... derives physical information about galaxies by fitting their UVto-far-IR SED (Noll et al. 2009b; Giovannoli et al. 2010). A Bayesian analysis is used to derive galaxy properties similar to that developed by Kauffmann et al. (2003a). CIGALE combines a UV-optical stellar SED and a dust, IR-emitting com ...
... derives physical information about galaxies by fitting their UVto-far-IR SED (Noll et al. 2009b; Giovannoli et al. 2010). A Bayesian analysis is used to derive galaxy properties similar to that developed by Kauffmann et al. (2003a). CIGALE combines a UV-optical stellar SED and a dust, IR-emitting com ...
Diapositiva 1 - Yale University
... 1779 Mayer publishes the first catalogue of double stars (80 entries) 1802 W. Herschel admits that the changes in Castor may be the ...
... 1779 Mayer publishes the first catalogue of double stars (80 entries) 1802 W. Herschel admits that the changes in Castor may be the ...
Angular Momentum Evolution of Young Low
... the best way to trace their angular momentum evolution from about 1 million years ago (Ma) to 1 billion years ago (Ga). This section discusses the observational studies of stellar rotation performed since the PPV review by Herbst al. (2007), for solar-type stars and lower-mass stars, down to the bro ...
... the best way to trace their angular momentum evolution from about 1 million years ago (Ma) to 1 billion years ago (Ga). This section discusses the observational studies of stellar rotation performed since the PPV review by Herbst al. (2007), for solar-type stars and lower-mass stars, down to the bro ...
Catching Planets in Formation with GMT
... • Substantial mismatch between predicted and observed distribution of exoplanets. • Major uncertainties: • How do gas-giant planets form. • How much do planets migrate. • Are there many habitable (water, etc) planets. ...
... • Substantial mismatch between predicted and observed distribution of exoplanets. • Major uncertainties: • How do gas-giant planets form. • How much do planets migrate. • Are there many habitable (water, etc) planets. ...
Fluorine abundances in dwarf stars of the solar neighbourhood⋆
... nine cool main-sequence dwarfs of the solar neighbourhood. The resolving power of the spectra was R ∼ 50 000 and the exposure times were chosen to achieve a signal-to-noise ratio (S/N) larger than 200. The reduction and calibration of the spectra were carried out with the standard CRIRES pipeline pr ...
... nine cool main-sequence dwarfs of the solar neighbourhood. The resolving power of the spectra was R ∼ 50 000 and the exposure times were chosen to achieve a signal-to-noise ratio (S/N) larger than 200. The reduction and calibration of the spectra were carried out with the standard CRIRES pipeline pr ...
A" Light," Centrally-Concentrated Milky Way Halo?
... halo was selected to have a quiet merger history, and the high resolution region was resampled with 13 million dark matter particles and an equal number of gas particles, for a mass resolution of mDM = 9.8 × 104 M⊙ and mSPH = 2 × 104 M⊙ , and a gravitational softening of 120 pc (physical). Star part ...
... halo was selected to have a quiet merger history, and the high resolution region was resampled with 13 million dark matter particles and an equal number of gas particles, for a mass resolution of mDM = 9.8 × 104 M⊙ and mSPH = 2 × 104 M⊙ , and a gravitational softening of 120 pc (physical). Star part ...
Towards a deterministic model of planetary formation. III. Mass
... to emerge and when they finally acquired Mc,acc , the solar nebula was already so severely depleted that they can only accreted a small amount of gaseous envelope (Hayashi et al. 1985). It is natural to extrapolate that GJ436b may also have attained Mc,acc but failed to accrete much gas. The main ch ...
... to emerge and when they finally acquired Mc,acc , the solar nebula was already so severely depleted that they can only accreted a small amount of gaseous envelope (Hayashi et al. 1985). It is natural to extrapolate that GJ436b may also have attained Mc,acc but failed to accrete much gas. The main ch ...
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.