Search Publications
A Detailed Analysis of a Magnetic Island Observed by WISPR on Parker Solar Probe
Liewer, Paulett C.; Gallagher, Brendan M.; Linton, Mark G. +4 more
We present the identification and physical analysis of a possible magnetic island feature seen in white-light images observed by the Wide-field Imager for Solar Probe (WISPR) on board the Parker Solar Probe. The island is imaged by WISPR during Parker's second solar encounter on 2019 April 6, when Parker was ∼38 R ⊙ from the Sun's cente…
Imaging of the Vega Debris System Using JWST/MIRI
Rieke, George H.; Gáspár, András; Beichman, Charles +6 more
We present images of the Vega planetary debris disk obtained at 15.5, 23, and 25.5 µm with the Mid-Infrared Instrument on JWST. The debris system is remarkably symmetric, smooth, and centered accurately on the star. There is a broad Kuiper-belt-analog ring at ∼80–170 au that coincides with the planetesimal belt detected with the Atacama Larg…
Icarus Revisited: An Ancient, Metal-poor Accreted Stellar Stream in the Disk of the Milky Way
Vitali, Sara; Cignoni, Michele; Lattanzi, Mario G. +2 more
The search for accreted satellites in the Galactic disk is a challenging task, to which Gaia plays a crucial role in synergy with ground-based spectroscopic surveys. In 2021, P. Re Fiorentin et al. discovered five substructures with disk kinematics including Icarus. To gain more insight into the origin of Icarus as a remnant of a dwarf galaxy rath…
Discovery of Two Different Full Disk Evolutionary Patterns of M-type T Tauri Stars with LAMOST DR8
Zhao, Yongheng; Duan, Fuqing; Li, Guang-Wei +2 more
The full disk, full of gas and dust, determines the upper limit of planet masses, and its lifetime is critical for planet formation, especially for giant planets. In this work, we studied the evolutionary timescales of the full disks of T Tauri stars (TTSs) and their relations to accretion. Combined with Gaia EDR3, Two Micron All Sky Survey, and W…
Visual Orbits of Wolf–Rayet Stars. I. The Orbit of the Dust-producing Wolf–Rayet Binary WR 137 Measured with the CHARA Array
Moffat, Anthony F. J.; Monnier, John D.; Schaefer, Gail H. +19 more
Classical Wolf–Rayet (W-R) stars are the descendants of massive OB stars that have lost their hydrogen envelopes and are burning helium in their cores prior to exploding as Type Ib/c supernovae. The mechanisms for losing their hydrogen envelopes are either through binary interactions or through strong stellar winds potentially coupled with episodi…
Using Polar Faculae to Determine the Sun's High-latitude Rotation Rate. I. Techniques and Initial Measurements
Sheeley, Neil R.
This paper describes a new way of determining the high-latitude solar rotation rate statistically from simultaneous observations of many polar faculae. In this experiment, I extracted frames from a movie made previously from flat-fielded images obtained in the 6767 Å continuum during 1997–1998 February and used those frames to construct spacetime …
Large Eruptive and Confined Flares in Relation to the Solar Active Region Evolution
Liu, Yu; Wang, Huaning; Rao, Changhui +5 more
Solar active regions (ARs) provide the required magnetic energy and the topology configuration for flares. Apart from conventional static magnetic parameters, the evolution of AR magnetic flux systems should have nonnegligible effects on magnetic energy store and the trigger mechanism of eruptions, which would promote the prediction for the flare …
The Plasma β in Quiet Sun Regions: Multi-instrument View
Veronig, Astrid; Podladchikova, Tatiana; Gömöry, Peter +4 more
A joint campaign of several spaceborne and ground-based observatories, such as the GREGOR solar telescope, the Extreme-ultraviolet Imaging Spectrometer (EIS), and the Interface Region Imaging Spectrograph (Hinode Observing Plan 381, 2019 October 11–22) was conducted to investigate the plasma β in quiet Sun regions. In this work, we focus on 2019 O…
Composition Variation of the 2023 May 16 Solar Energetic Particle Event Observed by SolO and PSP
Mitchell, D. G.; McComas, D. J.; Wimmer-Schweingruber, R. F. +13 more
In this study, we employ the combined charged particle measurements from Integrated Science Investigation of the Sun on board the Parker Solar Probe (PSP) and Energetic Particle Detector on board the Solar Orbiter (SolO) to study the composition variation of the solar energetic particle (SEP) event occurring on 2023 May 16. During the event, SolO …
Predicting Photospheric Ultraviolet Emission from Stellar Evolutionary Models
Liu, Jifeng; Wang, Song; Li, Xue +1 more
Stellar ultraviolet (UV) emission serves as a crucial indicator for estimating magnetic activity and evaluating the habitability of exoplanets orbiting stars. In this paper, we present a straightforward method to derive stellar photospheric UV emission for F to M main-sequence stars. By using PARSEC models, we establish relations between near-UV (…