Search Publications
Stellar Evolution in Real Time: Models Consistent with the Direct Observation of a Thermal Pulse in T Ursae Minoris
Joyce, Meridith; Molnár, László; Kiss, László L.
Most aspects of stellar evolution proceed far too slowly to be directly observable in a single star on human timescales. The thermally pulsing asymptotic giant branch (AGB) is one exception. The combination of state-of-the-art modeling techniques with data assimilated from observations collected by amateur astronomers over many decades provide, fo…
A Faint Halo Star Cluster Discovered in the Blanco Imaging of the Southern Sky Survey
Bechtol, K.; Allam, S.; Kuropatkin, N. +14 more
We present the discovery of a faint, resolved stellar system, BLISS J0321+0438 (BLISS 1), found in Dark Energy Camera data from the first observing run of the Blanco Imaging of the Southern Sky (BLISS) survey. BLISS J0321+0438 (BLISS 1) is located at ({α }2000,{δ }2000)=(177\buildrel{\circ}\over{.} 511,-41\buildrel{\circ}\ove…
Detection of a White Dwarf Companion to a Blue Straggler Star in the Outskirts of Globular Cluster NGC 5466 with the Ultraviolet Imaging Telescope (UVIT)
Stetson, Peter B.; Sahu, Snehalata; Côté, Patrick +8 more
We report the discovery of a hot white dwarf (WD) companion to a blue straggler star (BSS) in the globular cluster (GC) NGC 5466, based on observations from the Ultra-Violet Imaging Telescope (UVIT) on board AstroSat. The Spectral Energy Distribution (SED) of the Far-UV detected BSS NH 84 was constructed by combining the flux measurements from fou…
Galactic Gas Flows from Halo to Disk: Tomography and Kinematics at the Milky Way’s Disk-Halo Interface
Prochaska, J. Xavier; Werk, Jessica K.; O'Meara, John M. +4 more
We present a novel absorption-line survey using 54 blue horizontal branch stars in the Milky Way halo as background sources for detecting gas flows at the disk-halo interface. Distance measurements to high-latitude (b > 60°) background stars at 3.1-13.4 kpc, combined with unprecedented spatial sampling and spectral resolution, allow us to exami…
Spectral behavior of sulfides in simulated daytime surface conditions of Mercury: Supporting past (MESSENGER) and future missions (BepiColombo)
Hiesinger, H.; Maturilli, A.; Helbert, J. +2 more
To detect the mineral diversity of a planet's surface, it is essential to study the spectral variations over a broad wavelength range at relevant simulated laboratory conditions. The MESSENGER (Mercury Surface, Space Environment, Geochemistry, and Ranging) mission to Mercury discovered that irrespective of its formation closest to the Sun, Mercury…
On Solutions of the PFSS Model With GONG Synoptic Maps for 2006-2018
Nikolić; , L.
The potential field source surface (PFSS) model is widely used to derive the magnetic field of the solar corona. The only free parameter in the PFSS model is the radius of the so-called source surface, where magnetic field lines are forced to open. The radius of this surface is typically set to 2.5 solar radii in research and operational PFSS nume…
Six new rapidly oscillating Ap stars in the Kepler long-cadence data using super-Nyquist asteroseismology
Huber, Daniel; Bedding, Timothy R.; Howard, Andrew W. +6 more
We perform a search for rapidly oscillating Ap stars in the Kepler long-cadence data, where true oscillations above the Nyquist limit of 283.21 µHz can be reliably distinguished from aliases as a consequence of the barycentric time corrections applied to the Kepler data. We find evidence for rapid oscillations in six stars: KIC 6631188, KIC …
A three-dimensional map of the hot Local Bubble using diffuse interstellar bands
Javadi, Atefeh; van Loon, Jacco Th.; Khosroshahi, Habib G. +2 more
The Solar System is located within a low-density cavity known as the Local Bubble1-3, which appears to be filled with an X-ray-emitting gas at a temperature of 106 K (ref. 4). Such conditions are too harsh for typical interstellar atoms and molecules to survive2,3. The diffuse interstellar bands (DIBs), …
Dark disk substructure and superfluid dark matter
Alexander, Stephon; Bramburger, Jason J.; McDonough, Evan
Dark matter substructure has the potential to discriminate between broad classes of dark matter models. With this in mind, we construct novel solutions to the equations of motion governing condensate dark matter candidates, namely axion Bose-Einstein condensates and superfluids. These solutions are highly compressed along one axis and thus have a …
The fifth main-sequence magnetic B-type star showing coherent radio emission: Is this really a rare phenomenon?
Wade, Gregg A.; Chandra, Poonam; Das, Barnali +1 more
We report the discovery of intense, highly directional radio emission from the Bp star HD 35298, which we interpret as the consequence of Electron Cyclotron Maser Emission (ECME). The star was observed with the Giant Metrewave Radio Telescope near the rotational phases of both magnetic nulls in band 4 (550-750 MHz) and one of the nulls in band 5 (…