Search Publications
Missions
Journals
Publication Years
The morphological, elastic, and electric properties of dust aggregates in comets: A close look at COSIMA/Rosetta's data on dust in comet 67P/Churyumov-Gerasimenko
Kimura, Hiroshi; Merouane, Sihane; Paquette, John +2 more
The Cometary Secondary Ion Mass Analyzer (COSIMA) onboard ESA's Rosetta orbiter has revealed that dust particles in the coma of comet 67P/Churyumov-Gerasimenko are aggregates of small grains. We study the morphological, elastic, and electric properties of dust aggregates in the coma of comet 67P/Churyumov-Gerasimenko using optical microscopic imag…
Probing the atmosphere of HD189733b with the Na I and K I lines
Strassmeier, K. G.; Ilyin, I.; Steffen, M. +12 more
High spectral resolution transmission spectroscopy is a powerful tool to characterize exoplanet atmospheres. Especially for hot Jupiters, this technique is highly relevant, due to their high-altitude absorption, e.g. from resonant sodium (Na I) and potassium (K I) lines. We resolve the atmospheric K I absorption on HD189733b with the aim to compar…
The elusive tidal tails of the Milky Way globular cluster NGC 7099
Carballo-Bello, Julio A.; Piatti, Andrés E.; Catelan, Márcio +3 more
We present results on the extra-tidal features of the Milky Way globular cluster NGC 7099, using deep gr photometry obtained with the Dark Energy Camera (DECam). We reached nearly 6 mag below the cluster's main sequence (MS) turnoff, so that we dealt with the most suitable candidates to trace any stellar structure located beyond the cluster tidal …
Optical Linear Polarization toward the Open Star Cluster Casado Alessi 1
Yadav, R. K. S.; Medhi, Biman J.; Pandey, Jeewan C. +1 more
We present B-, V-, R-, and I-band linear polarimetric observations of 73 stars in the direction of open star cluster Casado Alessi 1 (hereafter Alessi 1). We aim to use polarimetry as a tool to investigate the properties and distribution of dust grains toward the direction of the cluster. The polarimetric observations were carried out using the AR…
USuRPER: Unit-sphere representation periodogram for full spectra
Zucker, S.; Binnenfeld, A.; Shahaf, S.
We introduce an extension of the periodogram concept to time-resolved spectroscopy. USuRPER, the unit-sphere representation periodogram, is a novel technique that opens new horizons in the analysis of astronomical spectra. It can be used to detect a wide range of periodic variability of the spectrum shape. Essentially, the technique is based on re…
Synoptic solar observations of the Solar Flare Telescope focusing on space weather
Sakurai, Takashi; Hanaoka, Yoichiro; Morita, Satoshi +2 more
The solar group at the National Astronomical Observatory of Japan is conducting synoptic solar observation with the Solar Flare Telescope. While it is a part of a long-term solar monitoring, contributing to the study of solar dynamo governing solar activity cycles, it is also an attempt at contributing to space weather research. The observations i…
Spectroscopic Studies of 30 Short-period Cataclysmic Variable Stars and Remarks on the Evolution and Population of Similar Objects
Thorstensen, John R.
We present spectroscopy and orbital periods Porb for 30 apparently nonmagnetic cataclysmic binaries with periods below ∼3 hr, nearly all of which are dwarf novae, mostly of the SU Ursae Majoris subclass. We then turn to the evidence supporting the prediction that short-period dwarf novae evolve toward longer periods after passing throug…
The Fundamental Plane of cluster spheroidal galaxies at z ∼ 1.3: evidence for mass-dependent evolution
Marchesini, D.; Annunziatella, M.; Gargiulo, A. +2 more
We present spectroscopic observations obtained at the Large Binocular Telescope in the field of the cluster XLSSJ0223-0436 at z = 1.22. We confirm 12 spheroids cluster members and determine stellar velocity dispersion for 7 of them. We combine these data with those in the literature for clusters RXJ0848+4453 at z = 1.27 (8 galaxies) and XMMJ2235-2…
Low-energy electron emission at the separation of gold-platinum surfaces induced by galactic cosmic rays on board LISA Pathfinder
Grimani, Catia; Villani, Mattia; Fabi, Michele +1 more
Galactic cosmic rays and solar energetic particles will induce spurious Coulomb forces on free-falling, gold-platinum test-masses on board the future interferometers for low-frequency gravitational wave detection in space. The European Space Agency mission LISA Pathfinder (LPF) was aimed to test the performance of instruments that will be placed o…
The Spatially Resolved Bipolar Nebula of Sakurai's Object. II. Mapping the Planetary Nebula Expansion
Matheson, Thomas; Hinkle, Kenneth H.; Joyce, Richard R. +2 more
Observations of the ejecta from the final flash (FF) of helium shell burning in Sakurai's Object (V4334 Sgr) are presented for 2015-2019, a period ∼20-24 yr after discovery. Adaptive optics images at Ks trace the expanding debris. While most of the ejecta mass is in ∼200 K dust, a small fraction, ∼0.4%, of the dust mass is at ∼760 K. Th…