Search Publications
Global Magnetosphere Response to Solar Wind Dynamic Pressure Pulses During Northward IMF Using the Heliophysics System Observatory
Moldwin, M. B.; Vidal-Luengo, S. E.
We analyzed the magnetospheric global response to dynamic pressure pulses (DPPs) using the Heliophysics System Observatory (HSO) and ground magnetometers. During northward Interplanetary Magnetic Field (IMF) Bz conditions, the magnetosphere acts as a closed "cavity" and reacts to solar wind DPPs more simply than during southward IMF. In this study…
On the Motion of Multiple Stars in the Pleiades Based on Gaia DR2
Danilov, V. M.
We estimated a number of parameters for small groups of stars in the open Pleiades star cluster using Gaia DR2 coordinate and proper motion data for stars in the region of radius d = 2.5° relative to the center of the cluster on the celestial sphere. We selected 36 wide pairs of stars with magnitudes mG < 15m and velocitie…
Multiwavelength Observations of the RV Tauri Variable System U Monocerotis: Long-term Variability Phenomena That Can Be Explained by Binary Interactions with a Circumbinary Disk
Stassun, Keivan G.; Kastner, Joel H.; Sabin, Laurence +7 more
We present an X-ray through submillimeter observations of the classical RV Tauri (RVb-type) variable U Mon, a post-asymptotic giant branch (AGB) binary with a circumbinary disk (CBD). Our SMA observations indicate a CBD diameter of ≲550 au. Our XMM-Newton observations make U Mon the first RV Tauri variable detected in X-rays. The X-ray emission is…
OGLE-2019-BLG-0304: Competing Interpretations between a Planet-binary Model and a Binary-source + Binary-lens Model
Han, Cheongho; Udalski, Andrzej; Lee, Chung-Uk +32 more
We analyze the microlensing event OGLE-2019-BLG-0304, whose light curve exhibits two distinctive features: a deviation in the peak region and a second bump appearing ~61 days after the main peak. Although a binary-lens model can explain the overall features, it leaves subtle but noticeable residuals in the peak region. We find that the residuals c…
Investigation on the spatiotemporal structures of supra-arcade spikes
Wang, Yuming; Liu, Rui
Context. The vertical current sheet (VCS) trailing coronal mass ejections (CMEs) is the key place at which the flare energy release and the CME buildup take place through magnetic reconnection. The VCS is often studied from the edge-on perspective for the morphological similarity with the two-dimensional "standard" picture, but its three-dimension…
Modeling the gravitational field by using CFD techniques
Yin, Zhi; Sneeuw, Nico
A harmonic scalar field has a Laplacian (i.e., both source-free and curl-free) gradient vector field and vice versa. Despite the good performance of spherical harmonic series on modeling the gravitational field generated by spheroidal bodies (e.g., the Earth), the series may diverge inside the Brillouin sphere enclosing all field-generating mass. …
H α fluxes and extinction distances for planetary nebulae in the IPHAS survey of the northern galactic plane
Barlow, M. J.; Sabin, L.; Jones, D. +7 more
We report H α filter photometry for 197 Northern hemisphere planetary nebulae (PNe) obtained using imaging data from the IPHAS survey. H α+[N II] fluxes were measured for 46 confirmed or possible PNe discovered by the IPHAS survey and for 151 previously catalogued PNe that fell within the area of the northern Galactic Plane surveyed by IPHAS. Afte…
Compound Eruptions of Twin Flux Ropes in a Solar Active Region
Zhang, Liang; Chen, Yao; Feng, Shiwei +6 more
Compound eruptions represent that multiple closely spaced magnetic structures erupt consecutively within a short interval, and then lead to a single flare and a single coronal mass ejection (CME). However, it is still subtle for the links between multiple eruptions and the associated single flare or/and single CME. In this Letter, we report the co…
The first spectroscopically confirmed brown dwarfs in NGC 2264
Scholz, Aleks; Teixeira, Paula S.; Mužić, Koraljka +2 more
We present spectroscopic follow-up observations of 68 red, faint candidates from our multi-epoch, multiwavelength, previously published survey of NGC 2264. Using near-infrared spectra from VLT/KMOS, we measure spectral types and extinction for 32 young low-mass sources. We confirm 13 as brown dwarfs in NGC 2264, with spectral types between M6 and …
Fast synthetic spectral fitting for large stellar samples: a critical test with 25 bright stars of known rotation
Snellen, I.; Schröder, K. -P.; Mittag, M. +2 more
This work presents and tests a reliable, but nonetheless fast, method for determining the physical parameters of large stellar samples with moderate-resolution spectra, with extensive host star-exoplanet studies in mind. The proposed strategy complements spectral synthesis for obtaining spectroscopically sensitive parameters (i.e. effective temper…