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A recipe based on physical principles employs the observed equivalent widths of 10 spectral lines to model the photosphere of a target star. Coupled with the visual magnitude and an absolute flux calibration, the recipe yields the angular radius, effective temperature, surface gravity, and metallicity. With the addition of a parallax, a linear radius and a mass estimate are added to the results. The method is applied to a sample of 26 G and K stars that span luminosity classes V to IIIa. The recipe-determined angular radii agree with the interferometer radii and have comparable errors. But unlike interferometers, the recipe is not limited to sizes ≳1 mas. The veracity of the other recipe-derived parameters is supported by numerous comparisons with previously published values. [ABSTRACT FROM AUTHOR]

High-resolution spectroscopic observations of the K0 II–III star α UMa were taken at the Elginfield Observatory over 11 years. Radial velocities were measured for nine of these years. They do not cover enough of the 44.5 year orbital period to give definitive elements on their own, but combined with published visual orbits, the spectroscopic-orbit parameters are well constrained. The spectra show no evidence of the secondary star, which remains an unsolved puzzle. Line-depth ratios show that α UMa has temperature variations ∼3 K, possibly periodic, over the 2001–2010 interval. Fourier analysis of the line broadening gives the projected rotation velocity of 2.66 ± 0.15 km s−1 and a radial-tangential macroturbulence dispersion of 4.97 ± 0.08 km s−1. The third-granulation signature shows the granulation velocities of α UMa to be essentially solar, with a scale factor of 0.98 ± 0.10. The absolute radial velocity of the star, with granulation blueshifts removed is −10,035 ± 100 m s−1 at the mean time of the observations, 2005.2544. The line bisector of Fe i λ6253 is normal and shows the classic “C” shape with the blue-most point commensurate with its absolute magnitude. Mapping this bisector on to the third signature gives a flux deficit similar to those of other giants, with a fractional area of 0.131, suggesting a temperature difference between granules and lanes of 127 K. The velocity position of the deficit is slightly higher than that for previously analyzed giants, extending the correlation with absolute magnitude. [ABSTRACT FROM AUTHOR]

The Fourier technique of extracting rotation rates and macroturbulence-velocity dispersions from the shapes and broadening of stellar spectral lines is applied to the solar-flux spectrum. Lines with equivalent widths less than ∼0.055 Å are shown to have the advantage over stronger lines by allowing the residual transform to be followed to higher frequencies. The standard radial-tangential macroturbulence formulation fits the observations well and yields an equatorial velocity that is within a few percent of the correct rate. [ABSTRACT FROM AUTHOR]

The velocity shifts of spectral lines as a function of line strength, so-called the third signature of granulation, are investigated using three published solar-flux atlases. We use flux atlases because we wish to treat the Sun as a star, against which stellar observations can be compared and judged. The atlases are critiqued and compared to the lower-resolution observations taken with the Elginfield stellar spectrograph. Third-signature plots are constructed for the 6020–6340 Å region. No dependence on excitation potential or wavelength is found over this wavelength span. The shape of the plots from the three solar atlases is essentially the same, with rms line-core velocity differences of 30–35 m s−1. High-resolution atlas data are degraded to the level of the Elginfield spectrograph and compared to direct observations taken with that spectrograph. The line-core velocities show good agreement, with rms differences of 38 m s−1. A new standard curve is derived and compared with the previously published one. Only small differences in shape are found, but a significant (+97 m s−1) change in the zero point is indicated. The bisector of the Fe i 6253 line is mapped onto the third-signature plots and flux deficits are derived, which measure the granule/lane flux imbalance. The lower spectral resolution lowers the flux deficit area slightly and moves the peak of the deficit 0.3–0.5 km s−1 toward higher velocities. These differences, while significant, are not large compared to measurement errors for stellar data. [ABSTRACT FROM AUTHOR]

Eleven seasons of spectroscopic data comprised of 107 exposures for the stable G8 III standard star, ε Vir are analyzed for projected rotation rate and granulation parameters. A Fourier analysis of the line shapes yield v sin i = 3.06 ± 0.20 km s−1 and a radial-tangential macroturbulence dispersion ζRT = 5.16 ± 0.08 km s−1. The radial velocity over nine seasons is constant to 18 m s−1. The absolute radial velocity with granulation blueshifts (but not gravitational redshift) removed is −14120 ± 75 m s−1. Line-depth ratios show the temperature to be constant to 0.7 K over 11 years, although a small secular rise or cyclic variation ∼1 K cannot be ruled out. The third-signature plot shows that the star has granulation velocities 10% larger than the Sun's. Mapping the Fe i λ6253 line bisector on to the third-signature plot indicates a normal-for-giants flux deficit area of 12.8%, indicating ∼134 K temperature difference between granules and lanes. Deficit velocities of GK giants are seen to shift to higher values with higher luminosity, ∼0.75 km s−1 over ΔMV ∼ 1.5, indicating larger velocity differences between granules and lanes for giants higher in the HR diagram. [ABSTRACT FROM AUTHOR]

The G7 IIIa single-lined spectroscopic binary, β Her, is studied with high-resolution, high-signal-to-noise spectra taken over 10 seasons from 23MR2000 to 10MY2009. Absolute radial velocities, corrected for convective blueshifts, are determined and new orbital parameters are derived. Line-depth ratios are used to measure temperature variation ∼2 K. A Fourier analysis is done for the line broadening, yielding a projected rotation velocity of 3.27 ± 0.20 km s−1 and a radial–tangential macroturbulence dispersion of 6.43 ± 0.08 km s−1. The “C” shaped bisector of Fe i λ6253 has its blue-most point at a relative flux level of 0.52, consistent with what is expected from β Her’s absolute magnitude. The third-signature plot indicates granulation velocities 20% larger than the Sun’s. Mapping the λ6253 line bisector onto the third-signature curve results in a flux deficit of 12.6 ± 1.0% that can be interpreted as arising from a temperature difference between granules and inter-granular lanes of 132 K. The flux deficit peaks near 5.5 km s−1 from the line center, suggesting the velocity difference between granules and lanes is ∼20% larger than that found for recently analyzed K giants. [ABSTRACT FROM AUTHOR]

The red giant α Ser was observed over 10 seasons, 2001–2010, at the Elginfield Observatory with the high-resolution coudé spectrograph. Season-mean radial velocities appear to show a small secular rise ∼11 ± 3 m s−1 yr−1. The absolute spectroscopic radial velocity with convective blueshifts taken into account is 2730 m s−1. Ten line-depth ratios were investigated and show that the star's temperature is constant with any secular variation below 1.3 ± 1.0 K over the 11 years of observation. Fourier analysis of the line broadening yields v sin i = 2.0 ± 0.3 km s−1 and a radial-tangential macroturbulence dispersion ζRT = 4.50 ± 0.10 km s−1. The third-granulation-signature plot shows that the granulation velocities of α Ser are only 0.55 ± 0.10 as large as the Sun's. The line bisector of Fe i λ6253 has the usual “C” shape and when mapped onto the third-signature plot results in a flux deficit that is slightly broader than seen in other measured K giants. The deficit fractional area of 12.3 ± 1.5% suggests a temperature difference between granules and lanes of 105 K as seen averaged over the stellar disk. [ABSTRACT FROM AUTHOR]

A correction to the article "A spectroscopic analysis of the K0 III binary ε cygni" published in the July 5, 2016 issue is presented.

Spectroscopic observations of ϵ Cyg (K0 III) taken over 12 seasons from 1999 to 2010 with a resolving power ∼100,000 are analyzed for radial velocities, granulation properties, and projected rotation rate. The new radial velocities, which are on an absolute velocity scale with convective blueshifts removed, contribute to the determination of the 55-year orbit parameters, but are insufficient to be definitive. Line-depth ratios show photospheric temperature variations amounting to ∼4 K, likely arising from a magnetic cycle. A small velocity variation, ∼100 m s−1, may mimic the temperature variations. Fourier analysis of the line broadening yields the projected rotation rate v sin i = 1.0 ± 0.2 and macroturbulence dispersion = 4.45 ± 0.05 km s−1. A possible rotation modulation in velocity with a period of ∼1.5 years is noted. The third signature of granulation, i.e., greater blueshifts for weaker lines, is measured and indicates a photospheric velocity gradient in ϵ Cyg that is 1.1 ± 0.1 times the Sun's, which is consistent with previously measured K giants. Mapping the line bisector of the Fe i λ6253 line on to the third-signature plot results in a flux deficit with a maximum 4.9 km s−1 redward of the line core and an amplitude of 16.5% ± 0.5% of the core depth, values typical of K giants. A 145 K disk-averaged temperature difference between granules and lanes is implied. [ABSTRACT FROM AUTHOR]

This review summarizes the presentations given at the 22nd International conference on Emerging Infectious Diseases in the Pacific Rim. The purpose of this annual meeting is to foster international collaborations and address important public health issues in the Asia-Pacific region. This meeting was held in Bangkok in February 2020 and focused on emerging virus infections. Unexpectedly, the SARS-CoV-2 pandemic was in the initial stages leading to a special session on COVID-19 in addition to talks on dengue, influenza, hepatitis, AIDS, Zika, chikungunya, rabies, cervical cancer and nasopharyngeal carcinoma. • Early recognition and response to SARS-CoV-2 entry into Thailand and Cambodia. • Pathogenesis of HIV, rabies, Lassa, chikungunya, coronavirus and paramyxovirus. • Improved diagnosis and treatment for norovirus, HBV and EBV infections. • Vaccine development for influenza, dengue, HIV, HCV and mosquito-borne pathogens. • Successful control of human papillomavirus infection through vaccination. [ABSTRACT FROM AUTHOR]