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Fast quasi-periodic oscillations in the eclipsing polar VV Puppis from VLT and XMM-Newton observations
Dhillon, V. S.; Bonnet-Bidaud, J. M.; Marsh, T. R. +7 more
We present high time resolution optical photometric data of the polar VV Puppis obtained simultaneously in three filters (u', HeII λ4686, r') with the ULTRACAM camera mounted at the ESO-VLT telescope. An analysis of a long 50 ks XMM-Newton observation of the source, retrieved from the database, is also provided. Quasi-periodic oscillations (QPOs) …
Characterizing some Gaia Alerts with LAMOST and SDSS
Liu, X.; Pursimo, T.; Dennefeld, M. +2 more
The ESA-Gaia satellite is regularly producing Alerts on objects where photometric variability has been detected after several passages over the same region of the sky. The physical nature of these objects has often to be determined with the help of complementary observations from ground-based facilities. We have compared the list of Gaia Alerts (f…
Discrete X-Ray Sources in Galaxy Clusters
Tugay, A. V.; Zadorozhna, L. V.; Shevchenko, S. Yu.
Current studies of extragalactic X-ray sources using data from orbital observatory XMM- Newton are at the front line of X-ray astronomy. Resolution capacity of the observatory instruments enable to detect separate X-ray sources in the close galaxies. In this study we used data from recently published 4XMM-DR9 catalog. This catalog contains 550124 …
On the Relation between Diffuse Bands and Other Interstellar Features
Krełowski, J.; Galazutdinov, G. A.; Siebenmorgen, R.
We discuss possible relations between different constituents of interstellar clouds, such as gas atoms (Fe I), simple molecular species (CH, CN), and the carriers of the puzzling diffuse interstellar bands (DIBs 5780, 5797, 5850 Å) as well as dust grains. We exemplify that abundances of carriers of these spectral features, revealed by the Doppler …
FSR19 and FSR25 confirmed as two new faint and metal-rich globular clusters in the galactic bulge
Minniti, D.; Alonso-García, J.; Gómez, M. +1 more
We combined the near-IR photometry from the VISTA Variables in the Vía Láctea extended Survey (VVVX) with Gaia EDR3 catalog to study some properties of FSR19 and FSR25. These are confirmed to be low luminosity metal-rich bulge globular clusters (Obasi et al. 2020). The proper motions (PM) remain unchanged and the Color magnitude diagrams (CMD) are…
Calibration Techniques for Studying Venus and Mars Atmospheres
Gramigna, Edoardo
The European Space Agency Venus Express mission (VEX) was sent to Venus in 2005 to unveil the unsolved mysteries regarding its atmosphere, the plasma environment and its temperatures. Radio occultation experiments performed by VeRa radio science instrument probed the planet's atmosphere by studying the frequency shift on the radio signal sent by t…
Latitude observations of the last century to obtain accurate independent latitude stations (INDLS) catalog of µδ for 682 Hipparcos stars and comparison with Gaia DR2
Damljanović, Goran
The independent latitude stations (INDLS) catalog of proper motion in declination µδ for 682 bright Hipparcos (HIP) stars is presented. It is obtained in the Hipparcos reference frame, and only the Hipparcos mean position at epoch 1991.25 is used for INDLS data to calculate independent µδ (the HIP µδ values are not included in th…
Seeing the Bigger Picture: Rosetta Mission Amateur Observing Campaign and Lessons for the Future
Roche, Paul; Norton, Andrew; Snodgrass, Colin +2 more
Amateur astronomers can make useful contributions to the study of comets. They add temporal coverage and multiscale observations that can aid the study of fast-changing and large-scale comet features. We document and review the amateur observing campaign set up to complement the Rosetta space mission, including the data submitted to date, and cons…
A New Candidate Luminous Blue Variable
Menten, Karl M.; Figer, Donald F.; Messineo, Maria +2 more
We identify IRAS 16115-5044, which was previously classified as a protoplanetary nebula (PPN), as a candidate luminous blue variable (LBV). The star has high luminosity (≳105.75 L⊙), ensuring supergiant status, has a temperature similar to LBVs, is photometrically and spectroscopically variable, and is surrounded by warm dust…
Influence of the convective mixing-length parameter α on the chemical abundances in the case of metal-poor giant HD 122563
Zhao, Gang; Song, Nan; Alexeeva, Sofya
One-dimensional (1D) model atmospheres are still the most commonly used tool for the determination of stellar chemical composition. Convection in the model is usually treated by mixing-length theory (MLT). The mixing-length parameter α is generally calibrated from the Sun and applied to all other stars. The metal-poor giant, HD 122563, is an impor…