Search Publications
Directly testing gravity with Proxima Centauri
Kroupa, Pavel; Banik, Indranil
The wide binary orbit of Proxima Centauri around α Centauri A and B differs significantly between Newtonian and Milgromian dynamics (MOND). By combining previous calculations of this effect with mock observations generated using a Monte Carlo procedure, we show that this prediction can be tested using high precision astrometry of Proxima Centauri.…
Characterizing Average Electron Densities in the Martian Dayside Upper Ionosphere
Gurnett, D. A.; Němec, F.; Morgan, D. D. +5 more
We use more than 10 years of the Martian topside ionospheric data measured by the Mars Advanced Radar for Subsurface and Ionosphere Sounding radar sounder on board the Mars Express spacecraft to derive an empirical model of electron densities from the peak altitude up to 325 km. Altogether, 16,044 electron density profiles obtained at spacecraft a…
A comparative study of size frequency distributions of Jupiter Trojans, Hildas and main belt asteroids: A clue to planet migration history
Terai, Tsuyoshi; Takato, Naruhisa; Ohtsuki, Keiji +4 more
Since 2002, we have obtained size frequency distributions (SFDs) of main belt asteroids (MBAs), Hildas, and Jupiter Trojans (JTs) by using the 8.2-m Subaru Telescope equipped with the wide-field CCD cameras: Suprime-Cam (SC) or Hyper Suprime-Cam (HSC). After combining these SFDs with SFDs obtained from other surveys, we performed a comparative stu…
Electron Intensity Measurements by the Cluster/RAPID/IES Instrument in Earth's Radiation Belts and Ring Current
Daly, P. W.; Kronberg, E. A.; Taylor, M. G. G. T. +7 more
The Cluster mission, launched in 2000, has produced a large database of electron flux intensity measurements in the Earth's magnetosphere by the Research with Adaptive Particle Imaging Detector (RAPID)/Imaging Electron Spectrometer (IES) instrument. However, due to background contamination of the data with high-energy electrons (>400 keV) and i…
Luminous and Variable Stars in NGC 2403 and M81
Humphreys, Roberta M.; Davidson, Kris; Gordon, Michael S. +2 more
We present the results of spectroscopy and multi-wavelength photometry of luminous and variable star candidates in the nearby spiral galaxies NGC 2403 and M81. We discuss specific classes of stars, the Luminous Blue Variables (LBVs), B[e] supergiants (sgB[e]), and the high-luminosity yellow hypergiants. We identify two new LBV candidates, and thre…
LQAC-5: The fifth release of the Large Quasar Astrometric Catalogue. A compilation of 592 809 objects with 398 697 Gaia counterparts
Barache, C.; Souami, D.; Souchay, J. +6 more
Context. In addition to their great astrophysical interest, quasars represent quasi-ideal reference objects in the celestial sphere with, a priori, a lack of significant proper motion. Since the fourth release of the Large Quasar Astrometric Catalogue (LQAC-4), a large number of quasars have been discovered, in particular those coming from the DR1…
High-degree gravity modes in the single sdB star HD 4539
Heber, U.; Reed, M. D.; Silvotti, R. +6 more
HD 4539 (alias PG 0044 + 097 or EPIC 220641886) is a bright (V = 10.2) long-period V1093 Her-type subdwarf B (sdB) pulsating star that was observed by the Kepler spacecraft in its secondary (K2) mission. We use the K2 light curve (78.7 d) to extract 169 pulsation frequencies, 124 with a robust detection. Most of these frequencies are found in the …
A BCG with Offset Cooling: Is the AGN Feedback Cycle Broken in A2495?
Gastaldello, F.; Ettori, S.; Amblard, A. +6 more
We present a combined radio/X-ray analysis of the poorly studied galaxy cluster A2495 (z = 0.07923) based on new EVLA and Chandra data. We also analyze and discuss Hα emission and optical continuum data retrieved from the literature. We find an offset of ∼6 kpc between the cluster brightest cluster galaxy (BCG) (MCG+02-58-021) and the peak of the …
So close, so different: characterization of the K2-36 planetary system with HARPS-N
Vanderburg, A.; Poretti, E.; Sozzetti, A. +19 more
Context. K2-36 is a K dwarf orbited by two small (Rb = 1.43 ± 0.08 R⊕ and Rc = 3.2 ± 0.3 R⊕), close-in (ab = 0.022 au and ac = 0.054 au) transiting planets discovered by the Kepler/K2 space observatory. They are representatives of two distinct families of small planets (Rp
First solar observations with ALMA
Loukitcheva, Maria
The Atacama Large Millimeter-Submillimeter Array (ALMA) has opened a new window for studying the Sun via high-resolution high-sensitivity imaging at millimeter wavelengths. In this contribution I review the capabilities of the instrument for solar observing and describe the extensive effort taken to bring the possibility of solar observing with AL…