Teacher`s Guide - Cornell Science Inquiry Partnerships
... This activity makes an analogy between stars and humans, which are easier to relate to. By having students graph properties of populations of humans based on a “snapshot” in time (i.e., a photograph or a census) and seeing what they can infer about these populations and how they change, the activity ...
... This activity makes an analogy between stars and humans, which are easier to relate to. By having students graph properties of populations of humans based on a “snapshot” in time (i.e., a photograph or a census) and seeing what they can infer about these populations and how they change, the activity ...
The Classification of Stellar Spectra
... Background: The History And Nature Of Spectral Classification Patterns of absorption lines were first observed in the spectrum of the sun by the German physicist Joseph von Fraunhofer early in the 1800’s, but it was not until late in the century that astronomers were able to routinely examine the sp ...
... Background: The History And Nature Of Spectral Classification Patterns of absorption lines were first observed in the spectrum of the sun by the German physicist Joseph von Fraunhofer early in the 1800’s, but it was not until late in the century that astronomers were able to routinely examine the sp ...
How Marius Was Right and Galileo Was Wrong Even Though
... these ideas will require further discussion and explanation. Lastly, he concedes to Galileo that the stars shine by their own light -- they are distinct in appearance from the planets (being notably more intense in brilliance).13 ...
... these ideas will require further discussion and explanation. Lastly, he concedes to Galileo that the stars shine by their own light -- they are distinct in appearance from the planets (being notably more intense in brilliance).13 ...
The accretion disk paradigm for young stars
... whereas the observed excess luminosity can be greater than L in extreme CTTSs. Even though the value of a typical CTTS luminosity excess was unknown in the early 1950s, it was already clear that it was orders of magnitude larger than what the accretion of interstellar cloud gas could provide. Faced ...
... whereas the observed excess luminosity can be greater than L in extreme CTTSs. Even though the value of a typical CTTS luminosity excess was unknown in the early 1950s, it was already clear that it was orders of magnitude larger than what the accretion of interstellar cloud gas could provide. Faced ...
Topic 3 - Holy Cross Collegiate
... absorbed. This creates the dark lines in the spectrum. Now think about the solar spectrum. If the Sun’s spectrum also has dark lines in it, it must mean that sunlight passes through some gases. The conclusion is that gases in the Sun’s atmosphere absorb the light that is removed from the solar spect ...
... absorbed. This creates the dark lines in the spectrum. Now think about the solar spectrum. If the Sun’s spectrum also has dark lines in it, it must mean that sunlight passes through some gases. The conclusion is that gases in the Sun’s atmosphere absorb the light that is removed from the solar spect ...
PPT - Chandra X-Ray Observatory
... The problem of metal-poor DA white dwarfs • Prominent example: HZ43 (Teff = 49,000 K), virtually metal free, shows no EUV or X-ray absorption features • Even more surprising: low metallicity of two DAs with even higher Teff. Two of hottest known DAs have extraordinarily low metal abundances: LB1919 ...
... The problem of metal-poor DA white dwarfs • Prominent example: HZ43 (Teff = 49,000 K), virtually metal free, shows no EUV or X-ray absorption features • Even more surprising: low metallicity of two DAs with even higher Teff. Two of hottest known DAs have extraordinarily low metal abundances: LB1919 ...
X-ray Astronomy and the search for Black Holes
... • The hard X-rays are optical thin, thermal emission from the accreting plasma, as also seen in magnetic and non-magnetic CVs • These symbiotic stars have harder spectra than non-magnetic CVs • Yet they are unlikely to have a magnetic white dwarf • Non-magnetic CVs can have high temperatures if the ...
... • The hard X-rays are optical thin, thermal emission from the accreting plasma, as also seen in magnetic and non-magnetic CVs • These symbiotic stars have harder spectra than non-magnetic CVs • Yet they are unlikely to have a magnetic white dwarf • Non-magnetic CVs can have high temperatures if the ...
The cosmic origin of fluorine and sulphur
... small white dwarf in the middle of the picture, and around it the elements the giant star has produced and expelled into its surroundings are clearly visible. In practice my result means that all the fluorine we come in contact with, including that in our toothpaste, likely has been formed like this ...
... small white dwarf in the middle of the picture, and around it the elements the giant star has produced and expelled into its surroundings are clearly visible. In practice my result means that all the fluorine we come in contact with, including that in our toothpaste, likely has been formed like this ...
star - Cloudfront.net
... a. As the planetary nebula disappears, gravity causes the remaining matter in the star to collapse inward. The star continues to collapse inward until it cannot be pressed down any further. b. What is left is an extremely dense core of matter known as a white dwarf. c. A white dwarf is about the siz ...
... a. As the planetary nebula disappears, gravity causes the remaining matter in the star to collapse inward. The star continues to collapse inward until it cannot be pressed down any further. b. What is left is an extremely dense core of matter known as a white dwarf. c. A white dwarf is about the siz ...
the UKIRT Fundamental and Extended lists
... We present high-precision JHK photometry with the 3.8-m UK Infrared Telescope (UKIRT) of 82 standard stars, 28 from the widely used preliminary list known as the ‘UKIRT Faint Standards’, referred to here as the Fundamental List, and 54 additional stars referred to as the Extended List. The stars hav ...
... We present high-precision JHK photometry with the 3.8-m UK Infrared Telescope (UKIRT) of 82 standard stars, 28 from the widely used preliminary list known as the ‘UKIRT Faint Standards’, referred to here as the Fundamental List, and 54 additional stars referred to as the Extended List. The stars hav ...
JHK standard stars for large telescopes: the UKIRT Fundamental
... We present high-precision JHK photometry with the 3.8-m UK Infrared Telescope (UKIRT) of 82 standard stars, 28 from the widely used preliminary list known as the ‘UKIRT Faint Standards’, referred to here as the Fundamental List, and 54 additional stars referred to as the Extended List. The stars hav ...
... We present high-precision JHK photometry with the 3.8-m UK Infrared Telescope (UKIRT) of 82 standard stars, 28 from the widely used preliminary list known as the ‘UKIRT Faint Standards’, referred to here as the Fundamental List, and 54 additional stars referred to as the Extended List. The stars hav ...
Early-type stars in the core of the young open cluster Westerlund 2
... 60 and 150 for the faintest and brightest sources respectively, with an average of ∼ 100 for a V = 14.5 star. Since the observations were taken only two days after full moon, the level of the background sky was rather high. Although we extracted the sky spectrum as close as possible to the source, s ...
... 60 and 150 for the faintest and brightest sources respectively, with an average of ∼ 100 for a V = 14.5 star. Since the observations were taken only two days after full moon, the level of the background sky was rather high. Although we extracted the sky spectrum as close as possible to the source, s ...
A Spectroscopic Survey of a Sample of Active M Dwarfs.
... One difficulty was detected after all analysis had been done: in some cases the velocity used for the template spectrum of HD95735 was in error by −3.00 km s−1 . Since all velocities are averages of the cross-correlation velocities using all three templates, some of our absorption velocities may hav ...
... One difficulty was detected after all analysis had been done: in some cases the velocity used for the template spectrum of HD95735 was in error by −3.00 km s−1 . Since all velocities are averages of the cross-correlation velocities using all three templates, some of our absorption velocities may hav ...
Surface Gravity as a Diagnostic ... Youth Cameron Higby-Naquin Advisor: Eric Jensen
... especially mass, will ultimately determine the age at which it enters a given stage of its evolution, but the stages themselves are another way to classify how a star ages. It is not enough to think of a star's age as simply a length of time; age must be viewed as a position in a star's overall deve ...
... especially mass, will ultimately determine the age at which it enters a given stage of its evolution, but the stages themselves are another way to classify how a star ages. It is not enough to think of a star's age as simply a length of time; age must be viewed as a position in a star's overall deve ...
Star Formation in Bok Globules - European Southern Observatory
... irregular manner, (4) The flux distribution of the star shows an infrared excess. All these criteria are fulfilled by Sernes 135. Observations with various telescopes on La Silla over the past two years have shown that Sernes 135 has a peculiar composite emission/absorption spectrum, wh ich can be i ...
... irregular manner, (4) The flux distribution of the star shows an infrared excess. All these criteria are fulfilled by Sernes 135. Observations with various telescopes on La Silla over the past two years have shown that Sernes 135 has a peculiar composite emission/absorption spectrum, wh ich can be i ...
PowerPoint
... • 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 ...
The Milky Way`s Restless Swarms of Stars
... would face a vista of 100,000 stars or more. Astronomers would have crisp views of binary partners that whip around each other in hours or minutes, pulsars that spin nearly 1000 times every second, and perhaps a nest of neutron stars or the event horizon of a sizable black hole at the center of it a ...
... would face a vista of 100,000 stars or more. Astronomers would have crisp views of binary partners that whip around each other in hours or minutes, pulsars that spin nearly 1000 times every second, and perhaps a nest of neutron stars or the event horizon of a sizable black hole at the center of it a ...
spectral lines as distant measurement tools
... type (horizontal). The horizontal axis follows Annie Cannon’s Harvard classification which you just rediscovered. Stars to the right have red appearance, to the left they are blue. The stellar brightness is measured as “photographic magnitude”, an inverted logarithmic scale for the amount of light r ...
... type (horizontal). The horizontal axis follows Annie Cannon’s Harvard classification which you just rediscovered. Stars to the right have red appearance, to the left they are blue. The stellar brightness is measured as “photographic magnitude”, an inverted logarithmic scale for the amount of light r ...
A trio of metalrich dust and gas discs found orbiting candidate white
... arm. The red spectra had relatively low signal-to-noise ratio (S/N). The blue spectra were debiased and flat-fielded using the STAR1 LINK packages KAPPA and FIGARO and then optimally extracted using the PAMELA2 code (Marsh 1989). The extracted spectra were wavelength calibrated using CuNe and CuAr a ...
... arm. The red spectra had relatively low signal-to-noise ratio (S/N). The blue spectra were debiased and flat-fielded using the STAR1 LINK packages KAPPA and FIGARO and then optimally extracted using the PAMELA2 code (Marsh 1989). The extracted spectra were wavelength calibrated using CuNe and CuAr a ...
THE N/O RATIO IN EARLY B-TYPE MAIN SEQUENCE STARS AS
... This paper is based on previous studies of MS B-stars which were published between 2000 and 2008 by Lyubimkov, et al. [8-12]. High resolution spectra for more than 100 MS B-stars were obtained [8] at two observatories, the Crimean Astrophysical Observatory and the MacDonald Observatory of the Unive ...
... This paper is based on previous studies of MS B-stars which were published between 2000 and 2008 by Lyubimkov, et al. [8-12]. High resolution spectra for more than 100 MS B-stars were obtained [8] at two observatories, the Crimean Astrophysical Observatory and the MacDonald Observatory of the Unive ...
High-precision abundances of elements in solar twin stars: Trends
... abundance ratios, [X/Fe], and elemental condensation temperature, T C , can be used as a signature of the existence of terrestrial planets around a star. > 600 for 21 solar twin stars in the solar neighborhood and the Sun (observed via reflected light from Aims. HARPS spectra with S /N ∼ asteroids) ...
... abundance ratios, [X/Fe], and elemental condensation temperature, T C , can be used as a signature of the existence of terrestrial planets around a star. > 600 for 21 solar twin stars in the solar neighborhood and the Sun (observed via reflected light from Aims. HARPS spectra with S /N ∼ asteroids) ...
pierrehumbert_lecture_1
... • Fusion of light elements into heavy elements • Hydrogen is by far the most abundant fuel in the Universe • Main sequence stars burn H into He • 90% of stars are main sequence stars • Stars do not evolve along the Main Sequence. they enter the Main Sequence when they start fusing H, and leave it wh ...
... • Fusion of light elements into heavy elements • Hydrogen is by far the most abundant fuel in the Universe • Main sequence stars burn H into He • 90% of stars are main sequence stars • Stars do not evolve along the Main Sequence. they enter the Main Sequence when they start fusing H, and leave it wh ...
Living with a Red Dwarf - Center for Space and Habitability (CSH)
... • Fusion of light elements into heavy elements • Hydrogen is by far the most abundant fuel in the Universe • Main sequence stars burn H into He • 90% of stars are main sequence stars • Stars do not evolve along the Main Sequence. they enter the Main Sequence when they start fusing H, and leave it wh ...
... • Fusion of light elements into heavy elements • Hydrogen is by far the most abundant fuel in the Universe • Main sequence stars burn H into He • 90% of stars are main sequence stars • Stars do not evolve along the Main Sequence. they enter the Main Sequence when they start fusing H, and leave it wh ...
Introduction - Cambridge University Press
... In this book you will study the processes that lead to the formation of stars, the energy sources that fuel them, what they do during their lifetimes, and what happens when their fuel runs out. It is assumed that you already have a general, qualitative idea of some events in the life cycles of stars ...
... In this book you will study the processes that lead to the formation of stars, the energy sources that fuel them, what they do during their lifetimes, and what happens when their fuel runs out. It is assumed that you already have a general, qualitative idea of some events in the life cycles of stars ...
Abundances and possible diffusion of elements in M 67 stars⋆
... equilibria of atoms and ions are known to be affected by departures from LTE, and since we aimed at exploring small differences in abundances between stars with different surface gravities (i.e. atmospheric pressures) and effective temperatures, we were anxious to avoid systematic errors due to the prob ...
... equilibria of atoms and ions are known to be affected by departures from LTE, and since we aimed at exploring small differences in abundances between stars with different surface gravities (i.e. atmospheric pressures) and effective temperatures, we were anxious to avoid systematic errors due to the prob ...
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.