The Clouds
... and molecular clouds form out of an expansive reservoir which occupies over 99% of the volume. This is the atomic interstellar medium. The gas is atomic because the ultraviolet light from massive stars dissociates any molecules much faster than they can reform (as discussed in §2.4.3) Only where mat ...
... and molecular clouds form out of an expansive reservoir which occupies over 99% of the volume. This is the atomic interstellar medium. The gas is atomic because the ultraviolet light from massive stars dissociates any molecules much faster than they can reform (as discussed in §2.4.3) Only where mat ...
Lab 7
... 10. How many Sun-like stars (remember, even if it's in the same spectral class as the Sun, it can't be part of a multiple-star system — except under certain circumstances!) are there on this model? What percentage of all the stars in the model are Sun-like? ...
... 10. How many Sun-like stars (remember, even if it's in the same spectral class as the Sun, it can't be part of a multiple-star system — except under certain circumstances!) are there on this model? What percentage of all the stars in the model are Sun-like? ...
The Star Finder Book - Starpath School of Navigation
... New navigators soon learn that these unknown stars may offer the only sights available for several days, and that this can occur much more often than was suspected. This is not just true in high-latitude oceans, famous for cloudy skies; it is a potential problem in all oceans including those of the ...
... New navigators soon learn that these unknown stars may offer the only sights available for several days, and that this can occur much more often than was suspected. This is not just true in high-latitude oceans, famous for cloudy skies; it is a potential problem in all oceans including those of the ...
PowerPoint Presentation - 16. Properties of Stars
... What have we learned? • What is the most important property of a star? • A star’s most important property is its mass, which determines its luminosity and spectral type at each stage of its life. • What are the three major classes of binary star systems? • A visual binary is a pair of orbiting star ...
... What have we learned? • What is the most important property of a star? • A star’s most important property is its mass, which determines its luminosity and spectral type at each stage of its life. • What are the three major classes of binary star systems? • A visual binary is a pair of orbiting star ...
TISHTRIYA - Earth`s second Sun
... The heliacal rising of Tishtriya in the pre-dawn sky Once in a year the heliacal rising of Tishtriya occurs when it first becomes visible above the eastern horizon for a brief moment just before sunrise, after a period of time when it had not been visible. Each day after the first heliacal rising, t ...
... The heliacal rising of Tishtriya in the pre-dawn sky Once in a year the heliacal rising of Tishtriya occurs when it first becomes visible above the eastern horizon for a brief moment just before sunrise, after a period of time when it had not been visible. Each day after the first heliacal rising, t ...
Observational studies of stellar rotation
... with the first zero occuring at ν1 ' (2/3)(c/λo ) · (v sin i)−1 . Thus, even without the knowledge of the intrinsic line profile, the projected stellar velocity can be precisely derived from the location of the first and subsequent zeroes in the Fourier transform of the observed profile. This powerf ...
... with the first zero occuring at ν1 ' (2/3)(c/λo ) · (v sin i)−1 . Thus, even without the knowledge of the intrinsic line profile, the projected stellar velocity can be precisely derived from the location of the first and subsequent zeroes in the Fourier transform of the observed profile. This powerf ...
Lab PDF - NMSU Astronomy
... along a narrow band that came to be called the Main Sequence. They also discovered that as one scanned the Main Sequence from one end to the other, the fundamental stellar property that changed along it was stellar mass. Mass is critically important because it determines how long stars can exist as ...
... along a narrow band that came to be called the Main Sequence. They also discovered that as one scanned the Main Sequence from one end to the other, the fundamental stellar property that changed along it was stellar mass. Mass is critically important because it determines how long stars can exist as ...
Chapter 18 - Origin and Evolution of Stars Chapter Preview
... together, they are generally believed to have been formed at roughly the same time and in the same neighborhood. In our Milky Way galaxy there are two main types of star clusters: open clusters and globular clusters (Figure 15). Open clusters are small and irregularly shaped, typically containing 10 ...
... together, they are generally believed to have been formed at roughly the same time and in the same neighborhood. In our Milky Way galaxy there are two main types of star clusters: open clusters and globular clusters (Figure 15). Open clusters are small and irregularly shaped, typically containing 10 ...
Jura et al. 2004 - Department of Physics and Astronomy
... template spectrum (Cohen et al 2003), and averaged the resulting spectra from corresponding nod positions. We plot the resulting spectra of our targets with IR excesses in Figure 1. Based upon comparisons of IRS spectra of non-variable calibration sources to ground-based, IRAS, and Spitzer IRAC flux ...
... template spectrum (Cohen et al 2003), and averaged the resulting spectra from corresponding nod positions. We plot the resulting spectra of our targets with IR excesses in Figure 1. Based upon comparisons of IRS spectra of non-variable calibration sources to ground-based, IRAS, and Spitzer IRAC flux ...
Chapter 15, Galaxies
... they much further away from us than the stars? • Before the 1920s, there were no reliable methods of measuring the distance to the galaxies. Many people believed that the galaxies were located within the Milky Way… How do we measure the distance of objects far away in the universe, much farther than ...
... they much further away from us than the stars? • Before the 1920s, there were no reliable methods of measuring the distance to the galaxies. Many people believed that the galaxies were located within the Milky Way… How do we measure the distance of objects far away in the universe, much farther than ...
The accretion disk paradigm for young stars
... had become much more acute when the IR properties of young stars were discovered, but by then this question was set aside as specialists were focusing on trying to understand the mass motions in the surroundings of young stars. 2.3. 1970s: pioneers and the great confusion The 1970s were a very contr ...
... had become much more acute when the IR properties of young stars were discovered, but by then this question was set aside as specialists were focusing on trying to understand the mass motions in the surroundings of young stars. 2.3. 1970s: pioneers and the great confusion The 1970s were a very contr ...
The Parallax Activity: Measuring the Distances to
... of less than 10% using ground-based measurements. Other techniques must be used (see Extension Activity D) beyond 200 light years. 4. The Hipparcos satellite (1989-93) measured the positions of stars with great accuracy, since it was above the fluctuat- ing ...
... of less than 10% using ground-based measurements. Other techniques must be used (see Extension Activity D) beyond 200 light years. 4. The Hipparcos satellite (1989-93) measured the positions of stars with great accuracy, since it was above the fluctuat- ing ...
Do We Know of Any Maunder Minimum Stars?
... activity level of the sun during the Maunder Minimum corresponded to that of these low-activity stars, S = 0.1451. Zhang et al. (1994) applied this value to an analysis of the effects of stellar activity on brightness and concluded that the Sun was 0.2 − 0.6% dimmer during the Maunder Minimum. Howev ...
... activity level of the sun during the Maunder Minimum corresponded to that of these low-activity stars, S = 0.1451. Zhang et al. (1994) applied this value to an analysis of the effects of stellar activity on brightness and concluded that the Sun was 0.2 − 0.6% dimmer during the Maunder Minimum. Howev ...
First firm spectral classification of an early-B pre-main
... et al. 2011). A (K-band) spectrum has been obtained for only a few of these (Hanson et al. 1997, 2002; Bik et al. 2006), and they show a red continuum, likely due to hot dust, and an emission-line spectrum that includes Brγ and, often, CO 2.3 μm bandhead emission. The latter emission can be modeled ...
... et al. 2011). A (K-band) spectrum has been obtained for only a few of these (Hanson et al. 1997, 2002; Bik et al. 2006), and they show a red continuum, likely due to hot dust, and an emission-line spectrum that includes Brγ and, often, CO 2.3 μm bandhead emission. The latter emission can be modeled ...
What is a white dwarf?
... Einstein’s theory of relativity says that nothing can move faster than light. [The speed of limit is the same relative to all observers.] When electron speeds in a white dwarf approach the speed of light, electron degeneracy pressure can no longer support the white dwarf. ...
... Einstein’s theory of relativity says that nothing can move faster than light. [The speed of limit is the same relative to all observers.] When electron speeds in a white dwarf approach the speed of light, electron degeneracy pressure can no longer support the white dwarf. ...
Observational properties of stars
... atmosphere of the Earth blocking some light, as well as stuff out in space blocking other types of light. So any apparent magnitude that you measure will not give you the full energy output of a star. Of course you could try to work around this by measuring light from stars in as many wavelengths as ...
... atmosphere of the Earth blocking some light, as well as stuff out in space blocking other types of light. So any apparent magnitude that you measure will not give you the full energy output of a star. Of course you could try to work around this by measuring light from stars in as many wavelengths as ...
103-122
... necessarily compatible with the theories of Galactic chemical evolution. If the αelements and the iron-group are synthesized in different stars, and gas clouds in the early Galaxy were poorly mixed, one may expect, as earlier and earlier generations of stars are examined, [α/Fe] to show an increasin ...
... necessarily compatible with the theories of Galactic chemical evolution. If the αelements and the iron-group are synthesized in different stars, and gas clouds in the early Galaxy were poorly mixed, one may expect, as earlier and earlier generations of stars are examined, [α/Fe] to show an increasin ...
Shortв•`lived radioactivity in the early solar system: The Superв•`AGB
... source close in time and space to the birth of the Sun. The first hypothesis proposed to obviate this problem was that the formation of the solar system was triggered by the same star that injected the SLR (Cameron and Truran 1977). In this case the SLR would have been injected in the proto-solar clo ...
... source close in time and space to the birth of the Sun. The first hypothesis proposed to obviate this problem was that the formation of the solar system was triggered by the same star that injected the SLR (Cameron and Truran 1977). In this case the SLR would have been injected in the proto-solar clo ...
33-3 - Fremont Peak Observatory
... ramp 10 years ago. It will be a major effort that will require more people than just the regulars. August is Solar eclipse month. We are planning to schedule a program the Saturday near the eclipse date (Monday Aug. 21st); however, several of our normal volunteers will be away and extra volunteer he ...
... ramp 10 years ago. It will be a major effort that will require more people than just the regulars. August is Solar eclipse month. We are planning to schedule a program the Saturday near the eclipse date (Monday Aug. 21st); however, several of our normal volunteers will be away and extra volunteer he ...
Stellar kinematics
Stellar kinematics is the study of the movement of stars without needing to understand how they acquired their motion. This differs from stellar dynamics, which takes into account gravitational effects. The motion of a star relative to the Sun can provide useful information about the origin and age of a star, as well as the structure and evolution of the surrounding part of the Milky Way.In astronomy, it is widely accepted that most stars are born within molecular clouds known as stellar nurseries. The stars formed within such a cloud compose open clusters containing dozens to thousands of members. These clusters dissociate over time. Stars that separate themselves from the cluster's core are designated as members of the cluster's stellar association. If the remnant later drifts through the Milky Way as a coherent assemblage, then it is termed a moving group.