Search Publications
On the Nature of the T Tauri Triple System
Chapillon, E.; Schaefer, G. H.; Guilloteau, S. +4 more
We present a multiwavelength analysis to reveal the nature of the enigmatic T Tauri triple star system. New optical and infrared measurements are coupled with archival X-ray, UV, and millimeter data sets to show the morphologies of disk material and outflow kinematics. A dark lane of obscuring material is seen in silhouette in several emission lin…
Physical Conditions of Gas Components in Debris Disks of 49 Ceti and HD 21997
Moór, Attila; Kóspál, Ágnes; Nomura, Hideko +2 more
Characterization of the gas component in debris disks is of fundamental importance for understanding their origin. To address this goal, we have conducted non-LTE (local thermodynamic equilibrium) analyses of the rotational spectral lines of CO including those of rare isotopologues (13CO and C18O) that have been observed towa…
Geometry of the Draco C1 Symbiotic Binary
Sarazin, Craig L.; Cunha, Katia; Smith, Verne V. +14 more
Draco C1 is a known symbiotic binary star system composed of a carbon red giant and a hot, compact companion—likely a white dwarf—belonging to the Draco dwarf spheroidal galaxy. From near-infrared spectroscopic observations taken by the Apache Point Observatory Galactic Evolution Experiment (APOGEE-2), part of Sloan Digital Sky Survey IV, we provi…
EVR-CB-004: An Inflated Hot Subdwarf O Star + Unseen WD Companion in a Compact Binary Discovered with the Evryscope
Law, Nicholas M.; Kupfer, Thomas; Glazier, Amy +10 more
We present the discovery of EVR-CB-004, a close binary with a remnant stellar core and an unseen white dwarf (WD) companion. The analysis in this work reveals that the primary is potentially an inflated hot subdwarf (sdO) and more likely is a rarer post-blue horizontal branch (post-BHB) star. Post-BHBs are the short-lived shell-burning final stage…
Solar Filaments and Interplanetary Magnetic Field Bz
Martens, Petrus C.; Aparna, V.
The direction of the axis of an interplanetary coronal mass ejection (ICME) plays an important role in determining if it will cause a geomagnetic disturbance in the Earth's magnetosphere upon impact. Long period southward-pointing ICME fields are known to cause significant space weather impacts and thus geomagnetic storms. We present an extensive …
A New Transition Wolf-Rayet WN/C Star in the Milky Way
Shi, Jianrong; Zhang, Tianmeng; Todt, Helge +7 more
We report the discovery of a new transition type Wolf-Rayet (W-R) WN/C star in the Galaxy. According to its coordinates (R.A., decl.)J2000 = ${18}^{{\rm{h}}}{51}^{{\rm{m}}}39\buildrel{\rm{s}}\over{.} 7$ , -05°34'51"1, and the distance (7.11 ${}_{-1.22}^{+1.56}\,$ kpc away from Earth) inferred from the second Gaia data release, it is fou…
Quantifying the Toroidal Flux of Preexisting Flux Ropes of Coronal Mass Ejections
Qiu, Jiong; Cheng, X.; Ding, M. D. +3 more
In past decades, much progress has been achieved in understanding the origin and evolution of coronal mass ejections (CMEs). In situ observations of the counterparts of CMEs, especially magnetic clouds (MCs) near the Earth, have provided measurements of the structure and total flux of CME flux ropes. However, it has been difficult to measure these…
Extraplanar Gas in Edge-on Galaxies Traced by SOFIA Observations of [C II]
Reach, William T.; Fadda, Dario; Stacey, Gordon J. +1 more
Bursts of localized star formation in galaxies can levitate material from the midplane. Spiral galaxies that are edge-on allow a clear distinction of material that is levitated off the galaxies' midplanes. We used SOFIA to measure the vertical distribution of [C II] 157.7 µm line emission for two nearby, edge-on galaxies, NGC 891 and NGC 590…
Cause and Kinematics of a Jetlike CME
Wang, Yuming; Joshi, Reetika; Chandra, Ramesh +3 more
In this article, we present the multiviewpoint and multiwavelength analysis of an atypical solar jet based on data from Solar Dynamics Observatory, SOlar and Heliospheric Observatory, and Solar TErrestrial RElations Observatory. It is generally believed that coronal mass ejections (CMEs) develop from the large-scale solar eruptions in the lower at…
Shear Measurement Bias Due to Spatially Varying Spectral Energy Distributions in Galaxies
Burchat, Patricia R.; Meyers, Joshua E.; Kamath, Sowmya +1 more
Galaxy color gradients (CGs)—I.e., spectral energy distributions that vary across the galaxy profile—will impact galaxy shape measurements when the modeled point-spread function (PSF) corresponds to that for a galaxy with spatially uniform color. This paper describes the techniques and results of a study of the expected impact of galaxy CGs on wea…