Stars A globular cluster is a tightly grouped swarm of stars held
... Points representing the brightest stars appear toward the top of the H-R diagram; points corresponding to the dimmest stars, toward the bottom. These points appear in groups that correspond to different kinds of stars. In the 1930's, American astronomers William W. Morgan and Philip C. Keenan invent ...
... Points representing the brightest stars appear toward the top of the H-R diagram; points corresponding to the dimmest stars, toward the bottom. These points appear in groups that correspond to different kinds of stars. In the 1930's, American astronomers William W. Morgan and Philip C. Keenan invent ...
Absolute magnitudes and kinematics of barium
... lies in a narrow range (0.5 − 0.7 M ), characteristic of white dwarfs stars, provided that the barium star has a mass in the range 1.3 − 2.2 M , typical for stars on the red giant branch (Jorissen et al. 1996). The obtained groups, given in Table 1, are characterized by different absolute magnitud ...
... lies in a narrow range (0.5 − 0.7 M ), characteristic of white dwarfs stars, provided that the barium star has a mass in the range 1.3 − 2.2 M , typical for stars on the red giant branch (Jorissen et al. 1996). The obtained groups, given in Table 1, are characterized by different absolute magnitud ...
PowerPoint Presentation - 16. Properties of Stars
... • How are stars classified into spectral types? • Stars are classified according to their spectra, with different spectral types generally corresponding to different temperatures. In order from hottest to coolest, the major spectral types are O, B, A, F, G, K, and M. These are subdivided into number ...
... • How are stars classified into spectral types? • Stars are classified according to their spectra, with different spectral types generally corresponding to different temperatures. In order from hottest to coolest, the major spectral types are O, B, A, F, G, K, and M. These are subdivided into number ...
CHAPTER 7—ATOMS AND STARLIGHT
... ____ 34. Blue stars are hotter than red stars. ____ 35. Isotopes of the same element have the same number of protons. ____ 36. Hydrogen alpha is the longest wavelength Balmer line. ____ 37. An absorption spectrum is also called a bright line spectrum. ____ 38. Stars of spectra type K have strong Bal ...
... ____ 34. Blue stars are hotter than red stars. ____ 35. Isotopes of the same element have the same number of protons. ____ 36. Hydrogen alpha is the longest wavelength Balmer line. ____ 37. An absorption spectrum is also called a bright line spectrum. ____ 38. Stars of spectra type K have strong Bal ...
Note
... • How strong is a Ba II line (at 0 eV) in a 6000K star compared to a 5000K star? • How do the strengths of a 5 eV Fe II line compare in the same two stars? • For Ba II, EQW decreases by 25% • For Fe II, EQW is almost x3 larger ...
... • How strong is a Ba II line (at 0 eV) in a 6000K star compared to a 5000K star? • How do the strengths of a 5 eV Fe II line compare in the same two stars? • For Ba II, EQW decreases by 25% • For Fe II, EQW is almost x3 larger ...
Chapter 15
... The star is so bright in part because it's nearing the end of its life, so it's puffed up a bit. It's "burned" through the hydrogen fuel in its core to make helium. The helium is basically just sitting there, so it's not producing any energy. Instead, the core is shrinking and getting hotter. Before ...
... The star is so bright in part because it's nearing the end of its life, so it's puffed up a bit. It's "burned" through the hydrogen fuel in its core to make helium. The helium is basically just sitting there, so it's not producing any energy. Instead, the core is shrinking and getting hotter. Before ...
Fluorine abundances in dwarf stars of the solar neighbourhood⋆
... synthesised in the merger of a helium white dwarf and a carbonoxygen white dwarf. Which of the above-mentioned sources is the most important one is currently under debate. In spite of the many uncertainties regarding the origin of F in the Galaxy, there have not been many observational studies of th ...
... synthesised in the merger of a helium white dwarf and a carbonoxygen white dwarf. Which of the above-mentioned sources is the most important one is currently under debate. In spite of the many uncertainties regarding the origin of F in the Galaxy, there have not been many observational studies of th ...
... Allen – This is indeed something to worry about, but I do not believe the discrepancies indicate motion. In the case of ADS 4186E the observations are nearly simultaneous. The last two points refer to measures by Mauray, using CCD astrometry and Mason, using speckle interferometry. Both points are s ...
Stellar Continua
... I. The Paschen Continuum • The Paschen continuum slope (B-V) is a good temperature indicator • Varies smoothly with changing temperature • Slope is negative (blue is brighter) for hot stars and positive (visual is brighter) for cooler stars • B-V works as a temperature indicator from 3500K to 9000K ...
... I. The Paschen Continuum • The Paschen continuum slope (B-V) is a good temperature indicator • Varies smoothly with changing temperature • Slope is negative (blue is brighter) for hot stars and positive (visual is brighter) for cooler stars • B-V works as a temperature indicator from 3500K to 9000K ...
Homologous Stellar Models and Polytropes Main Sequence Stars
... • As already shown by homology, L ∝ M a5 where for low-mass and highmass stars a5 = 5.5 and a5 = 3.0 were deduced respectively. The flattening at higher masses is due to the increased contribution of radiation pressure in the central core, which helps support the star and decreases the central tempe ...
... • As already shown by homology, L ∝ M a5 where for low-mass and highmass stars a5 = 5.5 and a5 = 3.0 were deduced respectively. The flattening at higher masses is due to the increased contribution of radiation pressure in the central core, which helps support the star and decreases the central tempe ...
Solar-type dynamo behaviour in fully convective stars without a
... level is reached at a Rossby number of approximately 0.13 ± 0.02 (ref. 9), corresponding to a rotation period that increases towards later spectral types, from 2 days for a star similar to the Sun to up to about 20 days for low-mass M dwarfs, and is also seen in both chromospheric emission and magn ...
... level is reached at a Rossby number of approximately 0.13 ± 0.02 (ref. 9), corresponding to a rotation period that increases towards later spectral types, from 2 days for a star similar to the Sun to up to about 20 days for low-mass M dwarfs, and is also seen in both chromospheric emission and magn ...
The Sculptor dwarf irregular galaxy SDIG: present and past
... near-infrared (J andK) imaging at the Anglo-Australian Telescope (AAT). Despite the presence of many blue stars, there are at present no detectable H II regions, indicating that the galaxy is now in a relatively quiescent state. However, the ratio of the H I mass to blue luminosity is typical of oth ...
... near-infrared (J andK) imaging at the Anglo-Australian Telescope (AAT). Despite the presence of many blue stars, there are at present no detectable H II regions, indicating that the galaxy is now in a relatively quiescent state. However, the ratio of the H I mass to blue luminosity is typical of oth ...
Labeling the HR Diagram - Mastering Physics Answers
... Spectral type is related to surface temperature, with stars of spectral type O having the highest surface temperature and stars of spectral type M having the lowest surface temperature. In other words, spectral type increases to the left on the HR diagram. Now proceed to Part E to determine how the ...
... Spectral type is related to surface temperature, with stars of spectral type O having the highest surface temperature and stars of spectral type M having the lowest surface temperature. In other words, spectral type increases to the left on the HR diagram. Now proceed to Part E to determine how the ...
11-Massive Stars
... The outflows are difficult to study because multiple outflows often emanate from the same large scale core. Clusters of stars form simultaneously in a core and the outflows originate from different protostars. For example, at least three molecular outflows are resolved in the core containing IRAS 05 ...
... The outflows are difficult to study because multiple outflows often emanate from the same large scale core. Clusters of stars form simultaneously in a core and the outflows originate from different protostars. For example, at least three molecular outflows are resolved in the core containing IRAS 05 ...
Entropy
... the most common type of stars. The satisfactory accuracy of this investigation based on observational data has been achieved thanks to the recently appeared techniques that enabled to determine, with sufficiently high accuracy, effective temperature Teff and bolometric correction BC of stars. 2. Obj ...
... the most common type of stars. The satisfactory accuracy of this investigation based on observational data has been achieved thanks to the recently appeared techniques that enabled to determine, with sufficiently high accuracy, effective temperature Teff and bolometric correction BC of stars. 2. Obj ...
Parent stars of extrasolar planets III: ρ1 Cancri Revisited
... employed in Paper I (two spectra of Vesta obtained in July 1996 with the 2.7 m) and also the Kurucz et al. (1984) Solar Flux Atlas. Most of the new lines were measured on all three solar spectra. The differences in the equivalent width values for the same lines in the three spectra lead to a scatter ...
... employed in Paper I (two spectra of Vesta obtained in July 1996 with the 2.7 m) and also the Kurucz et al. (1984) Solar Flux Atlas. Most of the new lines were measured on all three solar spectra. The differences in the equivalent width values for the same lines in the three spectra lead to a scatter ...
Entropy Production of Main-Sequence Stars
... ΣM turns out to be combined rather than based on experimental data only. This complicates the analysis of ΣM calculation error. 4. Data for Calculations and Their Accuracy To select clusters from the WEBDA database for investigation, the following criteria were applied: (1) availability of all the p ...
... ΣM turns out to be combined rather than based on experimental data only. This complicates the analysis of ΣM calculation error. 4. Data for Calculations and Their Accuracy To select clusters from the WEBDA database for investigation, the following criteria were applied: (1) availability of all the p ...
Heavy Element Abundances in Late-B and Early
... Unfortunately, the results from IUE data are constrained by their limited signal-to-noise ratio (S/ N ) (seldom more than 40:1 even for the very best co-added data) and limited resolution (k=k 12000). For a small number of CP stars, observations made with the Hubble Space Telescope’s Goddard High ...
... Unfortunately, the results from IUE data are constrained by their limited signal-to-noise ratio (S/ N ) (seldom more than 40:1 even for the very best co-added data) and limited resolution (k=k 12000). For a small number of CP stars, observations made with the Hubble Space Telescope’s Goddard High ...
Carbon, nitrogen, oxygen and lithium abundances of six
... The reductions were carried out using the code by Spite (1990). Further details on the data and a log-book of the observations are given in Paper I. As in Paper I, the well studied galactic supergiant Arcturus was used as a reference. A spectrum of Arcturus with a slightly higher resolution and an e ...
... The reductions were carried out using the code by Spite (1990). Further details on the data and a log-book of the observations are given in Paper I. As in Paper I, the well studied galactic supergiant Arcturus was used as a reference. A spectrum of Arcturus with a slightly higher resolution and an e ...
Constellation Classification Cards*
... 5. Ask the students from each constellation to identify themselves. As in the U-shaped model in Activity #1, the model should begin with the Sun and Sirius and end with Aludra from the constellation Canis Major. 6. Ask the students to consult their cards to find their brightness. A “0” on the brigh ...
... 5. Ask the students from each constellation to identify themselves. As in the U-shaped model in Activity #1, the model should begin with the Sun and Sirius and end with Aludra from the constellation Canis Major. 6. Ask the students to consult their cards to find their brightness. A “0” on the brigh ...
ppt - Astronomy at Swarthmore College
... Executive summary: Radiation-driven flows are inherently unstable; these flows are turbulent, and dissipate a lot of energy, shock-heating some fraction of the wind plasma to x-ray emitting temperatures. ...
... Executive summary: Radiation-driven flows are inherently unstable; these flows are turbulent, and dissipate a lot of energy, shock-heating some fraction of the wind plasma to x-ray emitting temperatures. ...
Amateur Spectroscopy: From Qualitative to Quantitative Analysis
... Most recently, the availability of spectrometers has made it possible for the amateur to do spectroscopy using moderate resolution. Coupled to sensitive CCD detectors, these instruments, coupled to even modest sized telescopes, allows the amateur to do a wide variety of projects such as classificat ...
... Most recently, the availability of spectrometers has made it possible for the amateur to do spectroscopy using moderate resolution. Coupled to sensitive CCD detectors, these instruments, coupled to even modest sized telescopes, allows the amateur to do a wide variety of projects such as classificat ...
How to interpret LPV in roAp stars Hiromoto Shibahashi , Don Kurtz
... Why do the LPV in Nd III and Pr III show such monotonic blue-to-red movement, while the photometric observations imply axisymmetric dipole oscillations, from which blueto-red-to-blue LPV are expected? The Nd III 6145 line-forming layer is moving with a maximum speed of 18 km s-1 in one pulsatio ...
... Why do the LPV in Nd III and Pr III show such monotonic blue-to-red movement, while the photometric observations imply axisymmetric dipole oscillations, from which blueto-red-to-blue LPV are expected? The Nd III 6145 line-forming layer is moving with a maximum speed of 18 km s-1 in one pulsatio ...
Chapter 4 Galactic Chemical Evolution
... of astronomical objects, in particular using spectroscopic techniques. The observed strengths of spectral lines depend on a variety of factors among which are the chemical abundances of the elements producing those spectral lines. Abundances can be measured in stellar photospheres from the strengths ...
... of astronomical objects, in particular using spectroscopic techniques. The observed strengths of spectral lines depend on a variety of factors among which are the chemical abundances of the elements producing those spectral lines. Abundances can be measured in stellar photospheres from the strengths ...
Stellar classification
In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Light from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the rainbow of colors interspersed with absorption lines. Each line indicates an ion of a certain chemical element, with the line strength indicating the abundance of that ion. The relative abundance of the different ions varies with the temperature of the photosphere. The spectral class of a star is a short code summarizing the ionization state, giving an objective measure of the photosphere's temperature and density.Most stars are currently classified under the Morgan–Keenan (MK) system using the letters O, B, A, F, G, K, and M, a sequence from the hottest (O type) to the coolest (M type). Each letter class is then subdivided using a numeric digit with 0 being hottest and 9 being coolest (e.g. A8, A9, F0, F1 form a sequence from hotter to cooler). The sequence has been expanded with classes for other stars and star-like objects that do not fit in the classical system, such class D for white dwarfs and class C for carbon stars.In the MK system a luminosity class is added to the spectral class using Roman numerals. This is based on the width of certain absorption lines in the star's spectrum which vary with the density of the atmosphere and so distinguish giant stars from dwarfs. Luminosity class 0 or Ia+ stars for hypergiants, class I stars for supergiants, class II for bright giants, class III for regular giants, class IV for sub-giants, class V for main-sequence stars, class sd for sub-dwarfs, and class D for white dwarfs. The full spectral class for the Sun is then G2V, indicating a main-sequence star with a temperature around 5,800K.