Search Publications
Missions
Journals
Publication Years
UVES analysis of red giants in the bulge globular cluster NGC 6522
Chiappini, C.; Bica, E.; Barbuy, B. +10 more
Context. NGC 6522 is a moderately metal-poor bulge globular cluster ([Fe/H] ~ −1.0), and it is a well-studied representative among a number of moderately metal-poor blue horizontal branch clusters located in the bulge. The NGC 6522 abundance pattern can give hints on the earliest chemical enrichment in the central Galaxy.
Aims: The aim of thi…
A Distance-deviation Consistency and Model-independent Method to Test the Cosmic Distance-Duality Relation
Fang, Guanwen; Zhou, Chichun; Hu, Jian +2 more
A distance-deviation consistency and model-independent method to test the cosmic distance-duality relation (CDDR) is provided. This method is worthy of attention for two reasons. First, a distance-deviation consistency method is used to pair subsamples: instead of pairing subsamples with redshift deviations smaller than a value of, say, $\left|{\r…
S stars and s-process in the Gaia era. II. Constraining the luminosity of the third dredge-up with Tc-rich S stars
Van Winckel, Hans; Wallerstein, George; Plez, Bertrand +6 more
Context. S stars are late-type giants that are transition objects between M-type stars and carbon stars on the asymptotic giant branch (AGB). They are classified into two types: intrinsic or extrinsic, based on the presence or absence of technetium (Tc). The Tc-rich or intrinsic S stars are thermally pulsing (TP-)AGB stars internally producing s-p…
Is the orbit of the exoplanet WASP-43b really decaying? TESS and MuSCAT2 observations confirm no detection
Tamura, M.; Pallé, E.; Béjar, V. J. S. +24 more
Up to now, WASP-12b is the only hot Jupiter confirmed to have a decaying orbit. The case of WASP-43b is still under debate. Recent studies preferred or ruled out the orbital decay scenario, but further precise transit timing observations are needed to definitively confirm or refute the period change of WASP-43b. This possibility is given by the Tr…
Kinetic Alfvén Waves in Space Plasma Environment with κ-electrons
Lakhina, G. S.; Singh, S. V.; Barik, K. C.
A resonant instability of kinetic Alfvén waves (KAWs) driven by ion beam is discussed through a theoretical model encompassing Maxwellian background ions and beam ions and non-Maxwellian κ-electrons. The ion beam velocity alone as a source is able to excite the KAWs up to a significant growth. The non-Maxwellian parameter κ impedes the growth of K…
The GALAH+ survey: a new library of observed stellar spectra improves radial velocities and hints at motions within M67
Lewis, Geraint F.; Ting, Yuan-Sen; Casey, Andrew R. +25 more
GALAH+ is a magnitude-limited survey of high-resolution stellar spectra obtained by the HERMES spectrograph at the Australian Astronomical Observatory. Its third data release provides reduced spectra with new derivations of stellar parameters and abundances of 30 chemical elements for 584 015 dwarfs and giants, 88 per cent of them in the Gaia magn…
Plasma densities, flow, and solar EUV flux at comet 67P. A cross-calibration approach
Nilsson, H.; Henri, P.; Edberg, N. J. T. +7 more
Context. During its two-year mission at comet 67P, Rosetta nearly continuously monitored the inner coma plasma environment for gas production rates varying over three orders of magnitude, at distances to the nucleus ranging from a few to a few hundred kilometres. To achieve the best possible measurements, cross-calibration of the plasma instrument…
Constraints on chameleon gravity from the measurement of the electrostatic stiffness of the M I C R O S C O P E mission accelerometers
Bergé, Joel; Pernot-Borràs, Martin; Uzan, Jean-Philippe +4 more
This article is dedicated to the use the MICROSCOPE mission's data to test chameleon theory of gravity. We take advantage of the technical sessions aimed to characterize the electrostatic stiffness of MICROSCOPE's instrument intrinsic to its capacitive measurement system. Any discrepancy between the expected and measured stiffness may result from …
The X-ray spectral and variability properties of typical radio-loud quasars
Brandt, W. N.; Zhu, S. F.; Timlin, John D.
We present X-ray spectral and long-term variability analyses of an unbiased sample of 361 optically selected radio-loud quasars (RLQs) utilizing sensitive serendipitous X-ray data from the Chandra and XMM-Newton archives. The spectral and temporal properties of RLQs are compared with those of radio-quiet quasars (RQQs) matched in L2500Å…
Venus Atmospheric Dynamics at Two Altitudes: Akatsuki and Venus Express Cloud Tracking, Ground-Based Doppler Observations and Comparison with Modelling
Widemann, Thomas; Machado, Pedro; Peralta, Javier +6 more