Search Publications
Improved Empirical Backgrounds for JWST NIRISS Image/Wide-field Slitless Spectroscopy Data Reduction
Momcheva, Ivelina G.; Hviding, Raphael E.; Clarke, Leonardo
The Near Infrared Imager and Slitless Spectrograph (NIRISS) on the James Webb Space Telescope (JWST) is a versatile instrument for collecting imaging and wide-field slitless spectroscopy (WFSS) data for surveys of galaxy clusters, emission-line galaxies, stellar populations, and more. Dispersed zodiacal light imprints distinct structures on space-…
Mass, Density, and Radius of Asteroid (16) Psyche from High-precision Astrometry
Chesley, Steven R.; Farnocchia, Davide; Park, Ryan S. +2 more
We characterize asteroid (16) Psyche using high-precision astrometry, including the recent Gaia Focused Product Release. The gravitational perturbations of Psyche on other asteroids can be observable in the case of mutual encounters. Using a least squares approach, we estimate the mass of Psyche by fitting astrometric data of asteroids that come w…
Occurrence Rates of Exosatellites Orbiting 3–30 M Jup Hosts from 44 Spitzer Light Curves
Vanderburg, Andrew; Dai, Fei; Vos, Johanna M. +1 more
We conduct a comprehensive search for transiting exomoons and exosatellites within 44 archival Spitzer light curves of 32 substellar worlds with estimated masses ranging between 3 and 30 M Jup. This sample's median host mass is 16 M Jup, inclusive of 14 planetary-mass objects, among which one is a wide-orbit exoplanet. We sea…
The AllWISE Catalog as an Infrared Celestial Reference Frame in the Gaia Era
Liu, N.; Zhu, Z.; Liu, J. -C. +3 more
The launch of Gaia in 2013 December ushered in a new era of space astrometry, allowing for fundamental reference research at an unprecedented level of precision. The international celestial reference frames in the radio band and the Gaia celestial reference frame in the optical band have been established and are consistent within several microarcs…
Detecting New Visual Binaries in Gaia DR3 with Gaia and Two Micron All Sky Survey (2MASS) Photometry. II. Speckle Observations of 16 Low-separation Systems
Stassun, Keivan G.; Lépine, Sébastien; Medan, Ilija +1 more
Here we present speckle observations of 16 low-separation (s < 30 au) high-probability candidate binaries from the catalog by Medan et al., where secondaries typically lack astrometric solutions in Gaia. From these speckle observations, we find a second component is always detected within the field of view. To determine if the detection is cons…
The Radiative–Convective Gap: Fact or Fiction?
Brandner, Wolfgang; Röser, Siegfried; Schilbach, Elena +1 more
Gaia characterizes the stellar populations of nearby open clusters with unprecedented precision. We investigate the Böhm-Vitense gap, which has been found as a prominent feature in the stellar sequence of open clusters. Using PARSEC isochrone fitting, we derive astrophysical parameters for more than 1100 bona fide single stars each in Praesepe, id…
The K2 and TESS Synergy. III. Search and Rescue of the Lost Ephemeris for K2's First Planet
Vanderburg, Andrew; Bieryla, Allyson; Latham, David W. +13 more
K2-2 b/HIP 116454 b, the first exoplanet discovery by K2 during its Two-Wheeled Concept Engineering Test, is a sub-Neptune (2.5 ± 0.1 R ⊕, 9.7 ± 1.2 M ⊕) orbiting a relatively bright (K S = 8.03) K-dwarf star on a 9.1 day period. Unfortunately, due to a spurious follow-up transit detection and ephemeris degradati…
Search for Young Stellar Objects within 4XMM-DR13 Using CatBoost and SPE
Zhang, Jingyi; Zhang, Yanxia; Kang, Zihan +3 more
Classifying and summarizing large data sets from different sky survey projects is essential for various subsequent scientific research. By combining data from 4XMM-DR13, Sloan Digital Sky Survey (SDSS) DR18, and CatWISE, we formed an XMM-WISE-SDSS sample that included information in the X-ray, optical, and infrared bands. By cross matching this sa…
A Partial Near-infrared Guide Star Catalog for Thirty Meter Telescope Operations
Subramaniam, Annapurni; Subramanian, Smitha; Anupama, G. C. +10 more
At first light, the Thirty Meter Telescope (TMT) near-infrared (NIR) instruments will be fed by a multiconjugate adaptive optics instrument known as the Narrow Field Infrared Adaptive Optics System (NFIRAOS). NFIRAOS will use six laser guide stars to sense atmospheric turbulence in a volume corresponding to a field of view of 2', but natural guide…
Verification of Hypervelocity Bulge Red Clump Stars
Poleski, Radosław; Wojtkowska, Gabriela
We verify candidate hypervelocity red clump stars located in the Galactic bulge that were selected based on the VVV and the Gaia DR2 data by Luna et al. To do so, we analyze data from the OGLE-IV survey: difference images and astrometric time series. We have data for 30 stars out of 34 hypervelocity candidates. We confirmed the high proper motion …