Search Publications
Five New Hot Jupiter Transits Investigated with Swift-UVOT
Rauscher, Emily; King, George W.; Reynolds, Mark +3 more
Short-wavelength exoplanet transit measurements have been used to probe mass loss in exoplanet atmospheres. We present the Swift-UVOT transit light curves for five hot Jupiters orbiting UV-bright F-type stars: XO-3, KELT-3, WASP-3, WASP-62, and HAT-P-6. We report one positive transit detection of XO-3b and one marginal detection of KELT-3b. We pla…
Hunting for Planetary Nebulae toward the Galactic Center
Hong, Jihye; An, Deokkeun; Ramírez, Solange V. +2 more
We present near-infrared (IR) spectra of two planetary nebula (PN) candidates in close lines of sight toward the Galactic center (GC) using the Gemini Near-Infrared Spectrograph at Gemini North. High-resolution images from radio continuum and narrowband IR observations reveal ringlike or barrel-shaped morphologies of these objects, and their mid-I…
Optical Variability of ICRF3 Quasars in the Pan-STARRS 3Pi Survey with Functional Principal Component Analysis
Makarov, V. V.; Goldman, B.; Berghea, C. T. +1 more
We make use of individual (epoch) detection data from the Pan-STARRS 3 survey for 2863 optical ICRF3 counterparts in the five wavelength bands g, r, i, z, and y, published as part of the Data Release 2. A dedicated method based on the Functional Principal Component Analysis is developed for these sparse and irregularly sampled data. With certain r…
Astrometric Mass Ratios of 248 Long-period Binary Stars Resolved in Hipparcos and Gaia EDR3
Makarov, Valeri V.; Fabricius, Claus
Using the absolute astrometric positions and proper motions for common stars in the Hipparcos and Gaia catalogs separated by 24.75 yr in the mean epoch, we compute mass ratios for long-period, resolved binary systems without any astrophysical assumptions or dependencies, except the presence of inner binary subsystems that may perturb the observed …
HD 63021: Chromospheric Activity and Mass Transfer in a Close Binary
Lester, Kathryn V.; Labadie-Bartz, Jonathan; Stringfellow, Guy S. +13 more
Prompted by X-ray detections from multiple surveys, we investigated the A-type star HD 63021 and found that it is a double-lined spectroscopic binary with highly variable emission associated with the primary star. Analysis of our multiepoch spectroscopic observations, the majority of which were carried out on small-aperture telescopes, indicates a…
Multiple Mg II Absorption Systems in the Lines of Sight to Quadruply Lensed Quasar H1413+1143
Minowa, Yosuke; Kashino, Daichi; Kashikawa, Nobunari +6 more
We find multiple Mg II absorption systems at redshift z = 1.66, 2.069, and 2.097 in the spatially resolved spectra of the quadruply gravitationally lensed quasar H1413+1143 utilizing the Kyoto tridimensional spectrograph II (Kyoto 3D II) spectrograph on board the Subaru telescope. Here we present the first measurement of differences in Mg II absor…
Far-ultraviolet Variables in M31: Concentration in Spiral Arms and Association with Young Stars
Buick, Megan; Postma, Joseph E.; Leahy, Denis A.
The Andromeda galaxy (M31) is an object of ongoing study with the Ultraviolet Imaging Telescope (UVIT) on AstroSat. Field 2, which is 6.4 kpc in diameter at the distance of M31, includes a substantial part of the NE spiral arms of the galaxy. We have obtained a second observation of Field 2 with the far-ultraviolet (FUV) F148W (148 nm) filter, sep…
AX UMa, an ab-type RR Lyrae Star with a Rapidly Decreasing Pulsation Period, and Its Binarity
Qian, S. -B.; He, J. -J.; Zhu, L. -Y. +2 more
The pulsation periods of RR Lyrae stars usually vary with time, and they are often used as probes to study the mechanism behind the variation. After the early discovery that the pulsation period of the RR Lyrae star AX UMa decreased rapidly, in further research, we made multiband photometric observations of this star using the Sino-Thai 70 cm tele…
Change-point Detection and Image Segmentation for Time Series of Astrophysical Images
Zezas, Andreas; Xu, Cong; Kashyap, Vinay L. +2 more
Many astrophysical phenomena are time-varying, in the sense that their intensity, energy spectrum, and/or the spatial distribution of the emission suddenly change. This paper develops a method for modeling a time series of images. Under the assumption that the arrival times of the photons follow a Poisson process, the data are binned into 4D grids…
Significant H I and Metal Differences around the z = 0.83 Lens Galaxy toward the Doubly Lensed Quasar SBS 0909+532
Kulkarni, Varsha P.; Lopez, Sebastian; Cashman, Frances H.
We report a large difference in neutral hydrogen (H I) and metal column densities between the two sight lines probing opposite sides of the lensing galaxy at zlens = 0.83 toward the doubly lensed quasar SBS 0909+532. Using archival HST-STIS and Keck HIRES spectra of the lensed quasar images, we measure log NH I = 18.77 ± 0.12…