Search Publications
AG Leonis Minoris-An evolved, detached eclipsing binary
Nelson, Robert H.
Radial velocity data and photometric light curves (in the B. V, and Ic passbands) for the detached eclipsing binary AG Leo Minoris were acquired-apparently for the first time-and are reported here. Roche modelling using the 2003 version of the Wilson-Devinney code was completed, yielding the basic parameters. The period appears to be co…
A Test of Gravitational Theories Including Torsion with the BepiColombo Radio Science Experiment
Schettino, Giulia; Serra, Daniele; Tommei, Giacomo +1 more
Within the framework of the relativity experiment of the ESA/JAXA BepiColombo mission to Mercury, which was launched at the end of 2018, we describe how a test of alternative theories of gravity, including torsion can be set up. Following March et al. (2011), the effects of a non-vanishing spacetime torsion have been parameterized by three torsion…
HST/FGS Trigonometric Parallaxes of M-dwarf Eclipsing Binaries
Schaefer, Gail H.; Nelan, Edmund P.; Ciardi, David R. +5 more
Hubble Space Telescope (HST) Fine Guidance Sensor (FGS) trigonometric parallax observations were obtained to directly determine distances to five nearby M-dwarf/M-dwarf eclipsing binary systems. These systems are intrinsically interesting as benchmark systems for establishing basic physical parameters for low-mass stars, such as luminosity L, and …
Environmental Impact on Star-forming Galaxies in a z ∼ 0.9 Cluster during the Course of Galaxy Accretion
Suzuki, Tomoko L.; Koyama, Yusei; Kodama, Tadayuki +18 more
Galaxies change their properties as they assemble into clusters. In order to understand the physics behind that, we need to go back in time and observe directly what is occurring in galaxies as they fall into a cluster. We have conducted a narrowband and J-band imaging survey on a cluster CL1604-D at z = 0.923 using a new infrared instrument SWIMS…
Multiwavelength Imaging and Spectral Analysis of Jet-like Phenomena in a Solar Active Region Using IRIS and AIA
Morgan, Huw; Humphries, Llŷr Dafydd; Verwichte, Erwin +1 more
High-resolution observations of dynamic phenomena give insights into the properties and processes that govern the low solar atmosphere. We present an analysis of jet-like phenomena emanating from a penumbral footpoint in active region (AR) 12192 using imaging and spectral observations from the Interface Region Imaging Spectrograph (IRIS) and the A…
The Nature of the Double Nuclei in the Barred S0 Galaxy IC 676
Zhou, Xu; Ma, Jun; Zhou, Zhimin +1 more
The lenticular galaxy IC 676 is a barred galaxy with double nuclei and active star formation in the central region. In this work we present the long-slit spectroscopy and archival multiwavelength images to investigate the nature and origin of the double nuclei in IC 676. Through photometric 1D brightness profiles and 2D image decomposition, we sho…
Guide star catalog generation of star sensors for interstellar navigation
Wu, Liang
In interstellar travel, parallax and stellar aberration have a non-negligible influence on the star identification of star sensors. Through the analysis of the working principle of star sensors, only the guide star catalog generation can solve this problem. The influence mechanism of parallax and stellar aberration is synthetically analyzed by fou…
Solar-cycle-related Changes in the Helium Ionization Zones of the Sun
Basu, Sarbani; Watson, Courtney B.
Helioseismic data for solar cycles 23 and 24 have shown unequivocally that solar dynamics changes with solar activity. Changes in solar structure have been more difficult to detect. Basu & Mandel had claimed that the then-available data revealed changes in the He II ionization zone of the Sun. The amount of change, however, indicated the need …
Understanding the Structure of Rapid Intensity Fluctuations in the Chromosphere with IRIS
De Pontieu, B.; Schmit, D.; Winebarger, A. +2 more
Several recent data sets have taken advantage of the unique capabilities of orbital and suborbital spacecraft to image the chromosphere and transition region at a very high cadence. We find that both the chromosphere and transition region exhibit spatially coherent transient features at frequencies above 80 mHz. We have analyzed narrowband imaging…
Doppler shifts and spectral line profile changes in the starlight scattered from an exoplanet
Anglada-Escudé, Guillem; Strachan, John B. P.
Scattered starlight from an exoplanet, commonly called reflected light, can be used to characterize the planet including the determination of its albedo and inclination of orbit. The relatively low flux ratio between directly observed starlight and starlight scattered off hot Jupiters make these systems the prime candidates for detection of reflec…