Search Publications
An infrared study of Galactic OH/IR stars - III. Variability properties of the Arecibo sample
García-Lario, P.; Engels, D.; Jiménez-Esteban, F. M. +2 more
We present the results of a near-infrared (NIR) monitoring programme carried out between 1999 and 2005 to determine the variability properties of the 'Arecibo sample of OH/IR stars'. The sample consists of 385 IRAS-selected Asymptotic Giant Branch (AGB) candidates, for which their O-rich chemistry has been proven by the detection of 1612 MHz OH ma…
A Search for TeV Gamma-Ray Emission from Pulsar Tails by VERITAS
Kargaltsev, Oleg; Klingler, Noel; Benbow, W. +55 more
We report on the search for very-high-energy gamma-ray emission from the regions around three nearby supersonic pulsars (PSR B0355+54, PSR J0357+3205, and PSR J1740+1000) that exhibit long X-ray tails. To date there is no clear detection of TeV emission from any pulsar tail that is prominent in X-ray or radio. We provide upper limits on the TeV fl…
HD 183579b: a warm sub-Neptune transiting a solar twin detected by TESS
Torres, Guillermo; Barclay, Thomas; Hellier, Coel +48 more
We report the discovery and characterization of a transiting warm sub-Neptune planet around the nearby bright (V = 8.75 mag, K = 7.15 mag) solar twin HD 183579, delivered by the Transiting Exoplanet Survey Satellite (TESS). The host star is located 56.8 ± 0.1 pc away with a radius of R* = 0.97 ± 0.02 R⊙ and a mass of M*<…
Variability of Disk Emission in Pre-main Sequence and Related Stars. V. Occultation Events from the Innermost Disk Region of the Herbig Ae Star HD 163296
Bayyari, Ammar; Sitko, Michael L.; Grady, Carol A. +8 more
HD 163296 is a Herbig Ae star that underwent a dramatic ~0.8 magnitude drop in brightness in the V photometric band in 2001 and a brightening in the near-IR in 2002. Because the star possesses Herbig-Haro objects traveling in outflowing bipolar jets, it was suggested that the drop in brightness was due to a clump of dust entrained in a disk wind, …
The contribution by luminous blue variable stars to the dust content of the Magellanic Clouds
Asmus, D.; Mehner, A.; de Wit, W. -J. +6 more
Context. Previous studies have concluded that low- and intermediate-mass stars cannot account for the interstellar dust yield in the Magellanic Clouds inferred from far-infrared and sub-millimetre observations.
Aims: Luminous blue variable stars (LBVs) form dust as a result of episodic, violent mass loss. To investigate their contribution as …
Dynamical modelling of CXOGBS J175553.2-281633: a 10 h long orbital period cataclysmic variable
Strader, Jay; Maccarone, Thomas J.; Jonker, Peter G. +8 more
We present modelling of the long-term optical light and radial velocity curves of the binary stellar system CXOGBS J175553.2-281633, first detected in X-rays in the Chandra Galactic Bulge Survey. We analysed 7 yr of optical I-band photometry from Optical Gravitational Lensing Experiment and found long-term variations from year to year. These long-…
A Deep Search for Five Molecules in the 49 Ceti Debris Disk
Hughes, A. Meredith; Roberge, Aki; Moór, Attila +9 more
Surprisingly strong CO emission has been observed from more than a dozen debris disks around nearby main-sequence stars. The origin of this CO is unclear, in particular whether it is left over from the protoplanetary disk phase or is second-generation material released from collisions between icy bodies like debris dust. The primary unexplored ave…
The IGRINS YSO Survey II: Veiling Spectra of Pre-main-sequence Stars in Taurus-Auriga
Tofflemire, Benjamin M.; López-Valdivia, Ricardo; Mace, Gregory +5 more
We present measurements of the H- and K-band veiling for 141 young stellar objects (YSOs) in the Taurus-Auriga star-forming region using high-resolution spectra from the Immersion Grating Near-Infrared Spectrometer. In addition to providing measurements of rH and rK, we produce low-resolution spectra of the excess emission ac…
Detection of coherent low-frequency radio bursts from weak-line T Tauri stars
Feeney-Johansson, A.; Purser, S. J. D.; Ray, T. P. +7 more
In recent years, thanks to new facilities such as LOFAR that are capable of sensitive observations, much work has been done on the detection of stellar radio emission at low frequencies. Such emission has commonly been shown to be coherent emission, generally attributed to electron-cyclotron maser (ECM) emission, and has usually been detected from…
Solar Soft X-ray Irradiance Variability, I: Segmentation of Hinode/XRT Full-Disk Images and Comparison with GOES (1 - 8 Å) X-Ray Flux
DeLuca, Edward; Weber, Mark; Adithya, H. N. +6 more
It is of great interest and importance to study the variabilities of solar EUV, UV and X-ray irradiance in heliophysics, in Earth's climate, and space weather applications. A careful study is required to identify, track, monitor and segment the different coronal features such as active regions (ARs), coronal holes (CHs), the background regions (BG…