Search Publications
NEOWISE Observations of Distant Active Long-period Comets C/2014 B1 (Schwartz), C/2017 K2 (Pan-STARRS), and C/2010 U3 (Boattini)
Masiero, Joseph R.; Milewski, Dave G.; Pittichová, Jana +3 more
Hyperactive comet activity typically becomes evident beyond the frost line (∼3–4 au) where it becomes too cold for water-ice to sublimate. If carbon monoxide (CO) and carbon dioxide (CO2) are the species that drive activity at sufficiently large distances, then detailed studies on the production rates of these species are extremely valu…
Magnetically Aligned Striations in the L914 Filamentary Cloud
Fang, Min; Gong, Yan; Chen, Xuepeng +6 more
We present CO(J = 1–0) multiline observations toward the L914 dark cloud in the vicinity of the Cygnus X region, using the 13.7 m millimeter telescope of the Purple Mountain Observatory. The CO observations reveal in the L914 cloud a long filament with an angular length of ∼3.°6, corresponding to approximately 50 pc at the measured distance of ∼ 7…
Search for Classical Cepheids in Galactic Open Clusters and Calibration of the Period–Wesenheit–Metallicity Relation in the Gaia Bands
Xu, Ye; Liu, Dejian; Hao, Chaojie +3 more
It is beneficial to calibrate the period–Wesenheit–metallicity relation (PWZR) of Delta Cephei stars (DCEPs), i.e., classical Cepheids, using accurate parallaxes of associated open clusters (OCs) from Gaia data release 3 (DR3). To this aim, we obtain a total of 43 OC–DCEPs (including 33 fundamental mode, 9 first overtone mode, and 1 multimode DCEP…
Revisit of 77 Clusters Candidates with Multiple Main Sequences using Gaia DR3
Li, Zhongmu; Chen, Jing; Zhang, Su +2 more
Gaia DR3 data provide the latest and full astrometric data for more than 1.5 billion sources, and these allow us to revisit the 77 special open cluster candidates collected from LISC star cluster catalog. According to their unclear color-magnitude-diagram (CMD) morphology, they are difficult to be ensured as real open clusters (OCs), and their clu…
Absolute Calibration. IV. Use of G-type Stars as Primary Calibrators
Rieke, G. H.; Willmer, Christopher; Proffitt, Charles R. +1 more
We demonstrate an approach to determine spectral energy distribution (SED) templates that are accurate to the 1% level from the visible through the infrared for nearby (unextincted) solar-type stars. Our approach is based only on measurements of T eff, log(g), and M/H and the use of standard theoretical SED models. The success of this a…
Short-period Variables in TESS Full-frame Image Light Curves Identified via Convolutional Neural Networks
Powell, Brian P.; Barclay, Thomas; Kruse, Ethan +9 more
The Transiting Exoplanet Survey Satellite (TESS) mission measured light from stars in ∼85% of the sky throughout its 2 yr primary mission, resulting in millions of TESS 30-minute-cadence light curves to analyze in the search for transiting exoplanets. To search this vast data set, we aim to provide an approach that is computationally efficient, pr…
Age Analysis of Extrasolar Planets: Insight from Stellar Isochrone Models
Narang, Mayank; Swastik, C.; Banyal, Ravinder K. +2 more
There is growing evidence from stellar kinematics and galactic chemical evolution suggesting that giant planets (M P ≥ 0.3M J ) are relatively young compared to the most commonly occurring population of small planets (M P < 0.3M J ). To further test the validity of these results, we analyzed the…
HST SHEL: Enabling Comparative Exoplanetology with HST/STIS
Sing, David K.; Stevenson, Kevin B.; López-Morales, Mercedes +12 more
The Hubble Space Telescope (HST) has been our most prolific tool to study exoplanet atmospheres. As the age of JWST begins, there are a wealth of HST archival data that are useful to strengthen our inferences from JWST. Notably, HST/Space Telescope Imaging Spectrograph (STIS), with its 0.3–1 µm wavelength coverage, extends past JWST's 0.6 &m…
High-resolution Spectroscopic Analysis of Four Unevolved Barium Stars
Pereira, C. B.; Holanda, N.; Drake, N. A. +4 more
A classical local thermodynamic equilibrium analysis, based on high-resolution spectroscopic data, is performed for a sample of three potential barium dwarf candidates and one star already recognized as such. We derived their atmospheric parameters, estimated their masses and luminosities, and determined chemical abundances for a set of 21 element…
JWST-TST DREAMS: Nonuniform Dayside Emission for WASP-17b from MIRI/LRS
Stevenson, Kevin B.; MacDonald, Ryan J.; Valenti, Jeff A. +23 more
We present the first spectroscopic characterization of the dayside atmosphere of WASP-17b in the mid-infrared using a single JWST MIRI/LRS eclipse observation. From forward-model fits to the 5–12 µm emission spectrum, we tightly constrain the heat redistribution factor of WASP-17b to be 0.92 ± 0.02 at the pressures probed by this data, indic…