Search Publications
Discovery of new stellar groups in the Orion complex. Towards a robust unsupervised approach
Alves, João; Adamo, Angela; D'Onghia, Elena +1 more
We test the ability of two unsupervised machine learning algorithms, EnLink and Shared Nearest Neighbor (SNN), to identify stellar groupings in the Orion star-forming complex as an application to the 5D astrometric data from Gaia DR2. The algorithms represent two distinct approaches to limiting user bias when selecting parameter values and evaluat…
Spitzer + VLTI-GRAVITY Measure the Lens Mass of a Nearby Microlensing Event
Feliz, Dax L.; Zang, Weicheng; Gould, Andrew +26 more
We report the lens mass and distance measurements of the nearby microlensing event TCP J05074264+2447555 (Kojima-1). We measure the microlens parallax vector ${{\boldsymbol{\pi }}}_{{\rm{E}}}$ using Spitzer and ground-based light curves with constraints on the direction of lens-source relative proper motion derived from Very Large Telescope Interf…
Hunting for Runaways from the Orion Nebula Cluster
Tan, Jonathan C.; Eyer, Laurent; Farias, Juan P.
We use Gaia DR2 to hunt for runaway stars from the Orion Nebula Cluster (ONC). We search a region extending 45° around the ONC and out to 1 kpc to find sources that have overlapped in angular position with the cluster in the last ∼10 Myr. We find ∼17,000 runaway/walkaway candidates that satisfy this 2D traceback condition. Most of these are expect…
The Fornax 3D project: Globular clusters tracing kinematics and metallicities
Viaene, S.; Hilker, M.; Pinna, F. +15 more
Globular clusters (GCs) are found ubiquitously in massive galaxies and due to their old ages, they are regarded as fossil records of galaxy evolution. Spectroscopic studies of GC systems are often limited to the outskirts of galaxies, where GCs stand out against the galaxy background and serve as bright tracers of galaxy assembly. In this work, we…
The Gaia-ESO Survey: detection and characterisation of single-line spectroscopic binaries
Gilmore, G.; Bayo, A.; Mowlavi, N. +26 more
Context. Multiple stellar systems play a fundamental role in the formation and evolution of stellar populations in galaxies. Recent and ongoing large ground-based multi-object spectroscopic surveys significantly increase the sample of spectroscopic binaries (SBs) allowing analyses of their statistical properties.
Aims: We investigate the repe…
Unsupervised machine learning for transient discovery in deeper, wider, faster light curves
Andreoni, Igor; Mahabal, Ashish; Cooke, Jeff +7 more
Identification of anomalous light curves within time-domain surveys is often challenging. In addition, with the growing number of wide-field surveys and the volume of data produced exceeding astronomers' ability for manual evaluation, outlier and anomaly detection is becoming vital for transient science. We present an unsupervised method for trans…
Robo-AO M-dwarf Multiplicity Survey: Catalog
Baranec, Christoph; Duev, Dmitry A.; Jensen-Clem, Rebecca +10 more
We analyze observations from Robo-AO's field M dwarf survey taken on the 2.1 m Kitt Peak telescope and perform a multiplicity comparison with Gaia DR2. Through its laser-guided, automated system, the Robo-AO instrument has yielded the largest adaptive optics M dwarf multiplicity survey to date. After developing an interface to visually identify an…
Characterization of Temporarily Captured Minimoon 2020 CD3 by Keck Time-resolved Spectrophotometry
Duev, Dmitry A.; Riddle, Reed; Ip, Wing-Huen +42 more
We present time-resolved visible spectrophotometry of 2020 CD3, the second known minimoon. The spectrophotometry was taken with the Keck I/Low Resolution Imaging Spectrometer between wavelengths 434 and 912 nm in the B, g, V, R, I, and RG850 filters as it was leaving the Earth-Moon system on 2020 March 23 UTC. The spectrum of 2020 CD
Atmospheric compositions and observability of nitrogen-dominated ultra-short-period super-Earths
Mollière, Paul; Tsai, Shang-Min; Miguel, Yamila +1 more
We explore the chemistry and observability of nitrogen-dominated atmospheres for ultra-short-period super-Earths. We base the assumption that super-Earths could have nitrogen-filled atmospheres on observations of 55 Cancri e that favour a scenario with a high-mean-molecular-weight atmosphere. We take Titan's elemental budget as our starting point …
The Hidden Past of M92: Detection and Characterization of a Newly Formed 17° Long Stellar Stream Using the Canada-France Imaging Survey
Jensen, Jaclyn; Navarro, Julio F.; Cuillandre, Jean-Charles +17 more
We present an analysis of the structure, kinematics, and orbit of a newly found stellar stream emanating from the globular cluster M92 (NGC 6341). This stream was discovered in an improved matched-filter map of the outer Galaxy, based on a "color-color-magnitude" diagram, created using photometry from the Canada-France Imaging Survey and the Pan-S…