Search Publications
Missions
Journals
Publication Years
DBSCAN Clustering Algorithm for the Detection of Nearby Open Clusters Based on Gaia-DR2two
Gao, Xin-hua; Wang, Chao; Xu, Shou-kun +1 more
In this paper, we attempt to use the DBSCAN (Density-Based Spatial Clustering of Applications with Noise) clustering algorithm to detect nearby open clusters based on the Gaia Data Release 2 (Gaia-DR2). We select 594284 stars (within a distance of 100 pc to the Sun) from the Gaia-DR2 catalog, and construct a five-dimensional phase space (three-dim…
A New Einstein Cross Gravitational Lens of a Lyman-break Galaxy
Corradi, Romano L. M.; Vulcani, Benedetta; Negrello, Mattia +5 more
We report the study of an “Einstein Cross” configuration first identified in a set of HST images by Cerny et al. Deep spectroscopic observations obtained at the Spanish 10.4 m Gran Telescopio Canarias telescope, allowed us to demonstrate the lens nature of the system, that consists of a Lyman-break galaxy (LBG), not a quasi-stellar object as is us…
Neural Network for Solar Irradiance Modeling (NN-SIM)
Mauceri, Steffen; Coddington, Odele; Lyles, Danielle +1 more
An understanding of solar variability over a broad range of wavelengths and timescales is needed by scientists studying Earth's climate. While the current understanding of solar irradiance from measurements and models is maturing, there remain notable areas of discrepancy that highlight a lack of understanding of the variability in solar spectral …
Unveiling the nature of candidate high-mass young stellar objects in the Magellanic Clouds with near-IR spectroscopy
Meixner, Margaret; Reiter, Megan; Nayak, Omnarayani +1 more
As nearby neighbours to the Milky Way, the Large and Small Magellanic Clouds (LMC and SMC) provide a unique opportunity to study star formation in the context of their galactic ecosystems. Thousands of young stellar objects (YSOs) have been characterized with large-scale Spitzer and Herschel surveys. In this paper, we present new near-IR spectrosc…
Discovery of an Outbursting 12.8 Minute Ultracompact X-Ray Binary
Udalski, Andrzej; Mróz, Przemek; Skowron, Jan +2 more
We report the discovery of OGLE-UCXB-01, a 12.8 minute variable object located in the central field of Galactic bulge globular cluster Djorg 2. The presence of frequent, short-duration brightenings at such an ultrashort period in long-term OGLE photometry together with the blue color of the object in Hubble Space Telescope images and the detection…
A catalogue of oxygen-rich pulsating giants in the Galactic halo and the Sagittarius stream
Kendall, T. R.; Mauron, N.; Maurin, L. P. A.
To construct a catalogue of oxygen-rich (M) asymptotic giant branch (AGB) stars in the halo, complementing the catalogues of carbon-rich (C) stars, previous lists of Miras and SRa semi-regulars located in the northern hemisphere are merged and cleaned of various defects. After putting aside known C stars, characteristics such as colours and period…
A distortion solution for the Bok telescope with four CCD chips
Wang, N.; Peng, Q. Y.; Zhou, X. +2 more
The Beijing-Arizona Sky Survey (BASS) is an imaging survey that uses the 2.3-m Bok telescope at Kitt Peak. In order to realize the astrometric potential of the Bok telescope and improve the astrometry of BASS, a distortion solution for the Bok telescope is needed. In the past, we used a single lookup table to correct all the positional errors. How…
Data-driven modelling of the Van Allen Belts: The 5DRBM model for trapped electrons
Kretschmar, Peter; Ness, Jan-Uwe; Kuulkers, Erik +10 more
The magnetosphere sustained by the rotation of the Earth's liquid iron core traps charged particles, mostly electrons and protons, into structures referred to as the Van Allen Belts. These radiation belts, in which the density of charged energetic particles can be very destructive for sensitive instrumentation, have to be crossed on every orbit of…
Soft and hard X-ray dips in the light curves of γ Cassiopeiae
Smith, M. A.; Lopes de Oliveira, R.
The available six archival XMM-Newton observations of the anomalous X-ray emitter γ Cas (B0.5 IVe) have been surveyed for the presence of soft X-ray `dips' in X-ray light curves. In addition to discovering such events in the soft band (≤2 keV), we show that sometimes they are accompanied by minor, nearly simultaneous dips in the hard X-ray band. H…
Survey of Saturn Whistler Mode Hiss Intensity
Kurth, W. S.; Averkamp, T. F.; Menietti, J. D.
We have conducted an extensive survey of whistler mode hiss emission at Saturn using nearly the complete data set from the Cassini Radio and Plasma Wave Science investigation. We distinguish the hiss emission by frequency and intensity threshold criteria. The survey includes all longitudes and latitudes >25° for r < 10 RS, limited…