Search Publications
Shortest Microlensing Event with a Bound Planet: KMT-2016-BLG-2605
Han, Cheongho; Lee, Chung-Uk; Zang, Weicheng +17 more
With a planet-host mass ratio q = 0.012 ± 0.001, KMT-2016-BLG-2605 has the shortest Einstein timescale, tE = 3.41 ± 0.13 days, of any planetary microlensing event to date. This prompts us to examine the full sample of seven short (tE < 7 days) planetary events with good q measurements. We find that six have clustered Einst…
Fragmenting Active Asteroid 331P/Gibbs
Jewitt, David; Li, Jing; Kim, Yoonyoung
We describe active asteroid 331P/Gibbs (2012 F5) using archival Hubble Space Telescope (HST) data taken between 2015 and 2018. 331P is an outer main belt active asteroid with a long-lived debris trail that formed in 2011. Embedded in the debris trail we identify 19 fragments with radii between 0.04 and 0.11 km (albedo 0.05 assumed) containing abou…
Orbits and Masses of Binaries from Speckle Interferometry at SOAR
Mendez, Rene A.; Clavería, Rubén M.; Costa, Edgardo
We present results from Speckle inteferometric observations of 15 visual binaries and one double-line spectroscopic binary, carried out with the HRCam Speckle camera of the SOAR 4.1 m telescope. These systems were observed as a part of an on-going survey to characterize the binary population in the solar vicinity, out to a distance of 250 pc. We o…
A Method to Extract Spatially Resolved Polycyclic Aromatic Hydrocarbon Emission from Spitzer Spectra: Application to M51
Ho, Luis C.; Xie, Yanxia; Zhang, Lulu
The mid-infrared spectrum contains rich diagnostics to probe the physical properties of galaxies, among which the pervasive emission features from polycyclic aromatic hydrocarbons (PAHs) offer promising means of estimating the star formation rate (SFR) relatively immune from dust extinction. This paper investigates the effectiveness of PAH emissio…
Speckle Interferometry of Nearby Multiple Stars. II. 2007-2020 Positional Measurements and Orbits of Sixteen Objects
Dyachenko, V.; Beskakotov, A.; Maksimov, A. +3 more
Long-term monitoring at the 6 m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences made it possible to improve the orbits of 15 objects (HIP 689, HIP 3951, HIP 10438, HIP 43948, HIP 69962, HIP 95995, HIP 102029, HIP 102357, HIP 104383, HIP 105947, HIP 106255, HIP 108917, HIP 111546, HIP 113726, HIP 114922) and co…
Wavelength Dependence of Activity-induced Photometric Variations for Young Cool Stars in Hyades
Gaidos, Eric; Miyakawa, Kohei; Hirano, Teruyuki +3 more
We investigate photometric variations due to stellar activity that induce systematic radial-velocity errors (so-called "jitter") for the four targets in the Hyades open cluster observed by the K2 mission (EPIC 210721261, EPIC 210923016, EPIC 247122957, and EPIC 247783757). Applying Gaussian process regressions to the K2 light curves and the near-i…
HAT-P-58b-HAT-P-64b: Seven Planets Transiting Bright Stars
Torres, Guillermo; Sato, B.; Hébrard, G. +31 more
We report the discovery and characterization of seven transiting exoplanets from the HATNet survey. The planets, which are hot Jupiters and Saturns transiting bright Sun-like stars, include: HAT-P-58b (with mass Mp = 0.37 MJ, radius Rp = 1.33 RJ, and orbital period P = 4.0138 days), HAT-P-59b (Mp
UV Fluorescence Traces Gas and Lyα Evolution in Protoplanetary Disks
Herczeg, Gregory J.; Brown, Alexander; France, Kevin +5 more
Ultraviolet spectra of protoplanetary disks trace distributions of warm gas at radii where rocky planets form. We combine Hubble Space Telescope Cosmic Origins Spectrograph observations of H2 and CO emission from 12 classical T Tauri stars to more extensively map inner disk surface layers, where gas temperature distributions allow radia…
Astrometric Membership Tests for the Zinn-Newell-Gibson UV-bright Stars in Galactic Globular Clusters
Bond, Howard E.
In 1972, Zinn, Newell, & Gibson (ZNG) published a list of 156 candidate UV-bright stars they had found in 27 Galactic globular clusters (GCs), based on photographs in the U and V bands. UV-bright stars lie above the horizontal branch (HB) and blueward of the asymptotic giant branch (AGB) and red giant branch in the clusters' color-magnitude di…
A Distinct Population of Small Planets: Sub-Earths
Wu, Yanqin; Qian, Yansong
The sizes of small planets are known to be bimodal, with a gap separating planets that have lost their primordial atmospheres (super-Earths) and the ones that retain them (mini-Neptunes). Here, we report evidence for another distinct population at smaller sizes. By focusing on planets orbiting around GK dwarfs inward of 16 days and correcting for …