English
Related papers

Related papers: A method of Extracting Flat Field from Real Time S…

200 papers

In helioseismology, there is a well-known offset between observed and computed oscillation frequencies. This offset is known to arise from improper modeling of the near-surface layers of the Sun, and a similar effect must occur for models…

Astrophysics · Physics 2009-11-13 Hans Kjeldsen , Timothy R. Bedding , Joergen Christensen-Dalsgaard

With the rapid development of telescopes, both temporal cadence and the spatial resolution of observations are increasing. This in turn generates vast amount of data, which can be efficiently searched only with automated detections in order…

Solar and Stellar Astrophysics · Physics 2019-01-30 Q. Hao , P. F. Chen , C. Fang

The determination of horizontal velocity fields at the solar surface is crucial to understanding the dynamics and magnetism of the convection zone of the sun. These measurements can be done by tracking granules. Tracking granules from…

Astrophysics · Physics 2009-11-13 R. Tkaczuk , M. Rieutord , N. Meunier , T. Roudier

Sky models have been used in the past to calibrate individual low radio frequency telescopes. Here we generalize this approach from a single antenna to a two element interferometer and formulate the problem in a manner to allow us to…

Instrumentation and Methods for Astrophysics · Physics 2017-06-28 Divya Oberoi , Rohit Sharma , Alan E. E. Rogers

We consider the estimation of a common period for a set of functions sampled at irregular intervals. The problem arises in astronomy, where the functions represent a star's brightness observed over time through different photometric…

Applications · Statistics 2016-04-15 James P. Long , Eric C. Chi , Richard G. Baraniuk

We present a precise and complete procedure for processing spectral data observed by the 1-meter New Vacuum Solar Telescope (NVST). The procedure is suitable for both the sit-and-stare and raster-scan spectra. In this work, the geometric…

Solar and Stellar Astrophysics · Physics 2017-10-18 Yunfang Cai , Zhi Xu , Zhenggang Li , Yongyuan Xiang , Yuchao Chen , Yu Fu , Kaifan Ji

ESO's two FOcal Reducer and low dispersion Spectrographs (FORS) are the primary imaging cameras for the VLT. Since they are not direct-imaging cameras, the accuracy of photometry which can routinely be obtained is limited by significant sky…

Astrophysics · Physics 2007-05-23 W. Freudling , M. Romaniello , F. Patat , P. Moller , E. Jehin , K. O'Brien

Solar activity is an important driver of long-term climate trends and must be accounted for in climate models. Unfortunately, direct measurements of this quantity over long periods do not exist. The only observation related to solar…

Solar and Stellar Astrophysics · Physics 2023-01-12 Sophie Mathieu , Laure Lefèvre , Rainer von Sachs , Véronique Delouille , Christian Ritter , Frédéric Clette

Estimates of the photospheric magnetic, electric and plasma velocity fields are essential for studying the dynamics of the solar atmosphere, for example through the derivative quantities of Poynting and relative helicity flux and by using…

Solar and Stellar Astrophysics · Physics 2017-12-18 E. Lumme , J. Pomoell , E. K. J. Kilpua

The possibilities of organizing an observation service for solar activity in order to provide space weather forecasting are considered. The most promising at this stage is the creation of a ground-based observation network. Such a network…

Solar and Stellar Astrophysics · Physics 2023-03-06 A. G. Tlatov , A. A. Pevtsov

Forecasting load at the feeder level has become increasingly challenging with the penetration of behind-the-meter solar, as this self-generation (also called total generation) is only visible to the utility as aggregated net-load. This work…

Signal Processing · Electrical Eng. & Systems 2024-03-11 Allison M. Campbell , Soumya Kundu , Andrew P. Reiman , Orestis Vasios , Ian Beil , Andy Eiden

In the case of spatially-revolved helioseismic data (such as MDI, GONG, HMI), the usual mode-fitting analysis consists of fitting the 2l+1 individual m-spectra of a given multiplet (n, l) either individually or simultaneously. Such fitting…

Astrophysics · Physics 2008-10-13 D. Salabert , R. A. Garcia

Derivation of the following formulae for solar position as seen from orbiting planet based on a simplified model: sunrise direction formula, solar declination formula, sunrise equation, daylight duration formula, solar altitude formula,…

Popular Physics · Physics 2020-09-16 Ross Ure Anderson

We suggest a method that evaluates the horizontal velocity in the solar photosphere with easily observable values using a combination of neural network and radiative magnetohydrodynamics simulations. All three-component velocities of…

Solar and Stellar Astrophysics · Physics 2023-09-06 Hiroyuki Masaki , Hideyuki Hotta , Yukio Katsukawa , Ryohtaroh T. Ishikawa

X-rays and gamma-rays from astronomical sources such as solar flares are mostly absorbed by the Earth's atmosphere. Resulting electron-ion production rate as a function of height depends on the intensity and wavelength of the injected…

Earth and Planetary Astrophysics · Physics 2016-04-27 Sourav Palit , Suman Ray , Sandip K. Chakrabarti

Context. The PLAnetary Transits and Oscillations of stars (PLATO) mission will observe the same area of the sky continuously for at least two years in an effort to detect transit signals of an Earth-like planet orbiting a solar-like star.…

Earth and Planetary Astrophysics · Physics 2024-10-29 A. F. Krenn , M. Lendl , S. Sulis , M. Deleuil , S. J. Hofmeister , N. Jannsen , L. Fossati , J. De Ridder , D. Seynaeve , R. Jarolim , A. M. Veronig

The absorption of light by molecules in the atmosphere of Earth is a complication for ground-based observations of astrophysical objects. Comprehensive information on various molecular species is required to correct for this so called…

Instrumentation and Methods for Astrophysics · Physics 2021-11-18 Rune D. Kjærsgaard , Aaron Bello-Arufe , Alexander D. Rathcke , Lars A. Buchhave , Line K. H. Clemmensen

Utilizing the information in observations of a complex system to make accurate predictions through a quantitative model when observations are completed at time $T$, requires an accurate estimate of the full state of the model at time $T$.…

Chaotic Dynamics · Physics 2014-05-13 Zhe An , Daniel Rey , Henry D. I. Abarbanel

Co-rotating spots at different latitudes on the stellar surface generate periodic photometric variability and can be useful proxies to detect Differential Rotation (DR). DR is a major ingredient of the solar dynamo but observations of…

Solar and Stellar Astrophysics · Physics 2015-06-16 Timo Reinhold , Ansgar Reiners

We describe a new concept to correct for scintillation noise on high-precision photometry in large and extremely large telescopes using telemetry data from adaptive optics (AO) systems. Most wide-field AO systems designed for the current…

Instrumentation and Methods for Astrophysics · Physics 2014-11-25 James Osborn