Related papers: Towards Spectroscopically Detecting the Global Lat…

Luminosity, which is the total amount of radiant energy emitted by an object, is one of the most critical quantities in astrophysics for characterizing stars. Equally important is the temporal evolution of a star's luminosity because of its…

Measurements of the radius and limb brightening of the Sun provide important information about the solar atmosphere structure and temperature. The solar radius increases as the observation at radio frequency decreases, indicating that each…

Understanding the global rotational profile of the solar atmosphere and its variation is fundamental to uncovering a comprehensive understanding of the dynamics of the solar magnetic field and the extent of coupling between different layers…

Interplanetary Lyman alpha line profiles are derived from the SWAN H cell data measurements. The measurements cover a 6-year period from solar minimum (1996) to after the solar maximum of 2001. This allows us to study the variations of the…

T Tauri stars exhibit variability on all timescales, whose origin is still debated. On WTTS the variability is fairly simple and attributed to long-lived, ubiquitous cool spots. We investigate the long term variability of WTTS, extending up…

The Sun's global inertial modes are very sensitive to the solar differential rotation and to properties of the deep solar convection zone which are currently poorly constrained. These properties include the superadiabatic temperature…

This paper describes a new way of determining the high-latitude solar rotation rate statistically from simultaneous observations of many polar faculae. In this experiment, I extracted frames from a movie made previously from flat-fielded…

We use state-of-the-art radiation-MHD simulations and 3D non-LTE radiative transfer computations to investigate \Halpha\ line formation in the solar chromosphere and apply the results of this investigation to develop the potential of…

Digitized images of full disk CaK spectroheliograms from two solar observatories were used to study cycle variation of ephemeral regions (ERs) over ten solar cycles 14-23. We calculate monthly averaged unsigned latitude of ERs and compare…

We report signal-to-noise ratio SNR ~ 100 optical spectra for four DA white dwarf stars acquired with the GMOS spectrograph of the 8m Gemini north telescope. These stars have 18<g<19 and are around Teff ~ 12000 K, were the hydrogen lines…

Some studies suggest that the dust temperatures ($T_\mathrm{d}$) in high-redshift ($z\gtrsim 5$) Lyman break galaxies (LBGs) are high. However, possible observational bias in $T_\mathrm{d}$ is yet to be understood. Thus, we perform a simple…

The sensitivity of future gravitational wave (GW) observatories will be limited by thermal noise in a wide frequency band. To reduce thermal noise, the European GW observatory Einstein GW Telescope (ET) is suggested to use crystalline…

The surface granularity of small Solar System bodies is diverse through the different types of planetary bodies and even for specific objects it is often not known in detail. One of the physical properties that strongly depends on the…

We investigate astrophysical contributions to the statistical uncertainty of precision radial velocity measurements of stellar spectra. We analytically determine the uncertainty in centroiding isolated spectral lines broadened by Gaussian,…

At high frequencies beyond the acoustic cut-off, a peak-like structure is visible in the solar power spectrum. Known as the pseudo-modes, their frequencies have been shown to vary in anti-phase with solar magnetic activity. In this work, we…

The General Theory of Relativity predicts the redshift of spectral lines in the solar photosphere, as a consequence of the gravitational potential of the Sun. This effect can be measured from a solar disk-integrated flux spectrum of the…

The high electron temperature in galaxy clusters ($>1\,$keV or $>10^7\,$K) leads to corrections at the level of a few percent in their thermal Sunyaev-Zeldovich effect signatures. Both the size and frequency dependence of these corrections,…

Scattering polarization in the Sr I 4607.3 \AA \ line observed with high resolution is an important diagnostic of the Sun's atmosphere and magnetism at small spatial scales. At present, spatially resolved observations of this diagnostic are…

Aims. We use advanced 3D NLTE radiative magnetohydrodynamic simulations of the solar atmosphere to carry out detailed tests of chromospheric diagnostics at millimeter and submillimeter wavelengths. Methods. We focused on the diagnostics of…

Kjeldsen et al. (1995, AJ 109, 1313; astro-ph/9411016) have developed a new technique for measuring stellar oscillations and claimed a detection in the G subgiant eta Boo. The technique involves monitoring temperature fluctuations in a star…