Search Results - "Ayres, Thomas R."

In the Trenches of the Solar–Stellar Connection. II. Extreme Ultraviolet Flux–Flux Correlations across Solar Cycle 24 by Ayres, Thomas R.

“…Abstract Solar extreme-ultraviolet (EUV: 100–1100 Å) radiation rises in the 10 4  K upper chromosphere and hotter layers extending into the million-degree…”
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A light carbon isotope composition for the Sun by Lyons, James R., Gharib-Nezhad, Ehsan, Ayres, Thomas R.

“…Measurements by the Genesis mission have shown that solar wind oxygen is depleted in the rare isotopes, 17 O and 18 O, by approximately 80 and 100‰,…”
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The Origin of Weakened Magnetic Braking in Old Solar Analogs by Metcalfe, Travis S., Finley, Adam J., Kochukhov, Oleg, See, Victor, Ayres, Thomas R., Stassun, Keivan G., van Saders, Jennifer L., Clark, Catherine A., Godoy-Rivera, Diego, Ilyin, Ilya V., Pinsonneault, Marc H., Strassmeier, Klaus G., Petit, Pascal

“…Abstract The rotation rates of main-sequence stars slow over time as they gradually lose angular momentum to their magnetized stellar winds. The rate of…”
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Constraints on Magnetic Braking from the G8 Dwarf Stars 61 UMa and τ Cet by Metcalfe, Travis S., Strassmeier, Klaus G., Ilyin, Ilya V., van Saders, Jennifer L., Ayres, Thomas R., Finley, Adam J., Kochukhov, Oleg, Petit, Pascal, See, Victor, Stassun, Keivan G., Jeffers, Sandra V., Marsden, Stephen C., Morin, Julien, Vidotto, Aline A.

“…Abstract During the first half of their main-sequence lifetimes, stars rapidly lose angular momentum to their magnetized winds, a process known as magnetic…”
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Weakened Magnetic Braking in the Exoplanet Host Star 51 Peg by Metcalfe, Travis S., Strassmeier, Klaus G., Ilyin, Ilya V., Buzasi, Derek, Kochukhov, Oleg, Ayres, Thomas R., Basu, Sarbani, Chontos, Ashley, Finley, Adam J., See, Victor, Stassun, Keivan G., van Saders, Jennifer L., Sepulveda, Aldo G., Ricker, George R.

“…Abstract The consistently low activity level of the old solar analog 51 Peg not only facilitated the discovery of the first hot Jupiter, but also led to the…”
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THE STRUCTURE OF THE LOCAL INTERSTELLAR MEDIUM. VI. NEW Mg II, Fe II, AND Mn II OBSERVATIONS TOWARD STARS WITHIN 100 pc by Malamut, Craig, Redfield, Seth, Linsky, Jeffrey L, Wood, Brian E, Ayres, Thomas R

“…We analyze high-resolution spectra obtained with the Space Telescope Imaging Spectrograph onboard the Hubble Space Telescope toward 34 nearby stars ([< or =,…”
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In the Trenches of the Solar-stellar Connection. V. High-resolution Ultraviolet and X-Ray Observations of Sun-like Stars: The Curious Case of Procyon by Ayres, Thomas R.

“…Abstract A joint X-ray (0.2–2 keV) and ultraviolet (1150–3000 Å) time-domain study has been carried out on three nearby bright late-type stars, bracketing the…”
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In the Trenches of the Solar–Stellar Connection. III. The HST/COS Ecliptic-poles Stellar Survey (EclipSS) by Ayres, Thomas R.

“…Abstract The Ecliptic-poles Stellar Survey (EclipSS) collected far-ultraviolet (FUV: 1160–1420 Å) spectra of 49 nearby ( d ≲ 100 pc) F3–K3 main-sequence stars,…”
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On the Same Wavelength as the Space Telescope Imaging Spectrograph by Ayres, Thomas R.

“…Abstract The Hubble Space Telescope Imaging Spectrograph (STIS) is a powerful tool for high spectral resolution ultraviolet (UV; 1150–3200 Å) studies of bright…”
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Cracking the Conundrum of F-supergiant Coronae by Ayres, Thomas R.

“…Chandra X-ray and HST far-ultraviolet (FUV) observations of three early-F supergiants have shed new light on a previous puzzle involving a prominent member of…”
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A Closer Look at the Alpha Persei Coronal Conundrum by Ayres, Thomas R.

“…A ROSAT survey of the Alpha Per open cluster in 1993 detected its brightest star, the mid-F supergiant Persei: the X-ray luminosity and spectral hardness were…”
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Evolution of the solar ionizing flux by Ayres, Thomas R.

“…A young magnetically active Sun, with enhanced ionizing radiations and an elevated solar wind, might have contributed to erosion of the primordial atmosphere…”
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The Wind Temperature and Mass-loss Rate of Arcturus (K1.5 III) by Harper, Graham M., Ayres, Thomas R., O’Gorman, Eamon

“…Abstract In this paper we aim to constrain the wind temperature, outflow and turbulent velocities, ionization state, and mass-loss rate of the single red giant…”
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HST STIS Observations of ζ Aurigae A's Irradiated Atmosphere by Harper, Graham M., Bennett, Philip D., Brown, Alexander, Ayres, Thomas R., Ohnaka, Keiichi, Griffin, Elizabeth

“…Abstract The details of the processes responsible for heating the chromospheres of evolved cool stars remain uncertain. While most spectroscopic diagnostics…”
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Limits on Chromospheres and Convection among the Main-Sequence A Stars by Simon, Theodore, Ayres, Thomas R, Redfield, Seth, Linsky, Jeffrey L

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The Cycles of α Centauri by Ayres, Thomas R

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THE CURIOUS CASE OF THE ALPHA PERSEI CORONA: A DWARF IN SUPERGIANT'S CLOTHING? by AYRES, Thomas R

“…Alpha Persei (HD 20902: F5 Iab) is a luminous, nonvariable supergiant located at the blue edge of the Cepheid instability strip. It is one of the brightest…”
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Solar Forbidden Oxygen, Revisited by Ayres, Thomas R

“…Recent large reductions in the solar oxygen abundance, based on synthesis of photospheric O i, OH, and CO absorptions with 3D convection models, have provoked…”
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The Advanced Spectral Library (ASTRAL): Reference Spectra for Evolved M Stars by Carpenter, Kenneth G., Nielson, Krister E., Kober, Gladys V., Ayers, Thomas R., Wahlgren, Glenn M., Rau, Gioia

“…The HST Treasury Program Advanced Spectral Library Project: Cool Stars was designed to collect representative, high-quality UV spectra of eight evolved FM type…”
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IS THE SUN LIGHTER THAN THE EARTH? ISOTOPIC CO IN THE PHOTOSPHERE, VIEWED THROUGH THE LENS OF THREE-DIMENSIONAL SPECTRUM SYNTHESIS by Ayres, Thomas R, Lyons, J R, Ludwig, H-G, CAFFAU, E, Wedemeyer-Bohm, S

“…We consider the formation of solar infrared (2-6 mu m) rovibrational bands of carbon monoxide (CO) in CO5BOLD 3D convection models, with the aim of refining…”
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