Related papers: Towards Spectroscopically Detecting the Global Lat…
A parametric model of granulation employing a small number of parameters was developed. Synthetic spectra calculated using this model closely match observed spectra and, in particular, reproduce the asymmetries observed in spectral lines.…
We present a high spatial resolution map of the columnar electron temperature (Tc) of a region to the south west of the Trapezium in the Orion Nebula. This map was derived from Hubble Space Telescope images that isolated the primary lines…
The dependence on the temperature of photospheric line-depth ratios (LDRs) in the spectral range 6190-6280 A is investigated by using a sample of 174 ELODIE Archive stellar spectra of luminosity class from V to III. The rotational…
An extensive spectroscopic study on \xi Boo A (chromospherically active solar-type star) was conducted based on the spectra obtained in 2008 December though 2010 May, with an aim to detect any spectrum variability and to understand its…
Oscillations were observed across the whole solar disk using the Doppler shift and line depth of spectral lines from the CO molecule near 4666~nm with the National Solar Observatory's McMath/Pierce solar telescope. Power, coherence, and…
Previously-unexplored diagnostics of O IV in the extreme ultraviolet region 260-280 A are used to derive a temperature and density for a solar flare kernel observed on 2012 March 9 with the Extreme ultraviolet Imaging Spectrometer on the…
Solar pores are strongly magnetized regions lacking a photospheric penumbra and characterized by predominantly vertical magnetic fields. We present a multi-line study of flashes in a solar pore using high-resolution observations from the…
The intrinsic variability of stars, due to acoustic oscillations, surface granulation, and magnetic activity, introduces radial velocity (RV) jitter in spectral lines, obscuring true planetary signals and hindering the detection of…
Polar brightening of the Sun at radio frequencies has been studied for almost fifty years and yet a disagreement persists between solar atmospheric models and observations. Some observations reported brightening values much smaller than the…
We present the first high-resolution, simultaneous observations of the solar chromosphere in the optical and millimeter wavelength ranges, obtained with ALMA and the IBIS instrument at the Dunn Solar Telescope. In this paper we concentrate…
A fraction of the extreme horizontal branch stars of globular clusters exhibit a periodic light variability that has been attributed to rotational modulation caused by surface spots. These spots are believed to be connected to inhomogeneous…
The temporal variability of the telluric sodium layer is investigated by analyzing 28 nights of data obtained with the Colorado State University LIDAR experiment. The mean height power spectrum of the sodium layer was found to be well fit…
A 50 min time series of one-dimensional slit-spectrograms, taken in quiet sun at disk center, observed at the German Vacuum Tower Telescope (Observatorio del Teide), was used to study the global and spatial variations of different line…
The Galactic Cold Cores project has made Herschel observations of 116 fields where the Planck survey has found signs of cold dust emission. The fields contain sources in different environments and different phases of star formation. The…
We measure F814W Surface Brightness Fluctuations (SBF) for a sample of distant shell galaxies with radial velocities ranging from 4000 to 8000 km/s. The distance at galaxies is then evaluated by using the SBF method. For this purpose,…
We construct a Hertzsprung-Russell diagram for the stellar/substellar boundary based on a sample of 63 objects ranging in spectral type from M6V to L4. We report newly observed VRI photometry for all 63 objects and new trigonometric…
Accurate measurement of temperature in protoplanetary disks is critical to understanding many key features of disk evolution and planet formation, from disk chemistry and dynamics, to planetesimal formation. This paper explores the…
In Chen et al., 2023 (C23; arXiv:2304.09898), we introduced a new method to directly measure temperature fluctuations and applied it to a nearby dwarf galaxy, Mrk 71, finding a temperature fluctuation parameter $t^2 = 0.008\pm 0.043$. This…
Rotation is ubiquitous among massive stars. With rotation comes a deformation to the surface geometry, which in turn leads to alterations in the distribution of parameters across the surface including surface gravity, temperature and…
(Abridged) Wavelet analysis can be used to measure the power spectrum of solar wind fluctuations along a line in any direction with respect to the local mean magnetic field. This technique is applied to study solar wind turbulence in…