Search Publications
Project BMK10k: Zeiss Ballistische Messkammer with a 10k × 10k CCD for ground‑based PLATO support
Chini, Rolf; Strassmeier, Klaus G.; Granzer, Thomas +5 more
Ballistische Messkammer with 10k CCD's (BMK10k) central goal is supporting the upcoming PLAnetary Transits and Oscillation of stars (PLATO) mission by reducing its number of false positives (planet‑compatible transit candidates but not planets at the end). For Kepler, the number of false positives had been estimated to still be about 10%. Understa…
Oxygen Ion Flow Reversals in Earth's Magnetotail: A Cluster Statistical Study
Gunell, H.; Nilsson, H.; Hamrin, M. +5 more
We present a statistical study of magnetotail flows that change direction from earthward to tailward using Cluster spacecraft. More precisely, we study 318 events of particle flux enhancements in the O+ data for which the pitch angle continuously changes with time, either from 0° to 180° or from 180° to 0°. These structures are called "…
NOMAD/TGO and PFS/MEx joint analysis for the retrieval of trace gases in the Martian atmosphere
Nardi, Luca
Search for variable stars in the northern sky: analysis of photometric time series for 3598 stars
Tautvaišienė, G.; Drazdauskas, A.; Mikolaitis, Š. +6 more
As extensive ground-based observations and characterisation of different variable stars are of the utmost importance in preparing optimal input catalogues for space missions, our aim was to search for new variable stars in selected fields of the northern sky. We obtained 24 470 CCD images and analysed photometric time series of stars using the DAO…
Some Kinematical Properties of Solar Motion Using Stellar Associations
Elsanhoury, W. H.; Elkhateeb, M. M.
In this paper, we have constructed many models of the Solar motion and the kinematical properties for a sample of 5100 main sequence stars; into which 1528 early types (B5, A0, A5, F0, and F5) and about 3572 late types (G0, G5, K0, and K5). The sample was collected with aid of Extended Hipparcos Compilation (XHIP) Cross references. Based on the sp…
Photometry & spectrophotometry of the Herbig Ae star RR Tauri
Boyd, D.
Multicolour broadband photometry and flux-calibrated low-resolution spectroscopy, obtained between 2014 & 2018, are used to investigate the behaviour of the highly variable Herbig Ae star RR Tauri.
Solar Irradiance Variability, Influenced by r Modes
Wolff, Charles L.
A spectrum of the four-decade solar irradiance record has a prominent cluster of power for periodicities near 1 yr. Correlating irradiance with a bandpass filter showed that periodicity values were not constant, but varied sinusoidally with each cycle lasting 14 ± 1 yr. The large modulation amplitude makes solar frequencies ≥1 yr-1 hard…
Comparing photometric and trigonometric distance scales in the Galaxy with Gaia DR2
Kovaleva, D. A.; Piskunov, A. E.; Kharchenko, N. V.
The average trigonometric parallaxes, determined according to Gaia DR2 for 143 open clusters at distances up to 8.5 kpc, are compared with the distances to the same clusters, determined in the framework of the MWSC project by the method of isochrone fitting. It is shown that the agreement between the trigonometric and photometric distance scales f…
Hints of the Existence of C-rich Massive Evolved Stars
Cernicharo, José; Agúndez, Marcelino; Quintana-Lacaci, Guillermo +6 more
We aim to study the properties of a particular type of evolved stars, C-rich evolved stars with high expansion velocities. For this purpose we have focused on the two best studied objects within this group, IRC+10401 and AFGL 2233. We focused on determining their luminosity by studying their spectral energy distribution. Also, we have obtained sin…
Improvement of Simplified Models of Variability of Stars: A review
Andronov, I. L.
Astronomical data are typically irregular in time, e.g. the space (HIPPARCOS/TYCHO, KEPLER, GAIA, WISE etc.) and ground-based CCD (NSVS, ASAS, CRTS, SuperWASP etc.) and photographic (Harvard, Sonneberg, Odessa etc.) photometrical surveys. This leads to cancellation of the conditions, which lead to the orthogonality of the basic functions, and thus…