A5017589506- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Astrophysics and Star Formation Studies
- Galaxies: Formation, Evolution, Phenomena
- Cosmology and Gravitation Theories
- Primary Care and Health Outcomes
- Astro and Planetary Science
- Global Cancer Incidence and Screening
- Economic and Financial Impacts of Cancer
- Hospital Admissions and Outcomes
- Healthcare Policy and Management
- Colorectal Cancer Screening and Detection
Florida State University
2025
Whalen Biomedical
2023
St. Francis College
2023
Johns Hopkins University
2016-2022
Lund University
2020
We present an expanded sample of 75 Milky Way Cepheids with Hubble Space Telescope (HST) photometry and Gaia EDR3 parallaxes which we use to recalibrate the extragalactic distance ladder refine determination constant. All HST observations were obtained same instrument (WFC3) filters (F555W, F814W, F160W) used for imaging in Type Ia supernova (SN Ia) hosts. The WFC3 spatial scanning mode mitigate saturation reduce pixel-to-pixel calibration errors, reaching a mean photometric error 5...
Abstract We present Hubble Space Telescope (HST) photometry of a selected sample 50 long-period, low-extinction Milky Way Cepheids measured on the same WFC3 F 555 W -, 814 and 160 -band photometric system as extragalactic in Type Ia supernova host galaxies. These bright were observed with spatial scanning mode optical near-infrared to mitigate saturation reduce pixel-to-pixel calibration errors reach mean error 5 mmag per observation. use new Gaia DR2 parallaxes HST simultaneously constrain...
We present new parallax measurements of 7 long-period (> 10 days) Milky Way Cepheids (SS CMa, XY Car, VY VX Per, WZ Sgr, X Pup and S Vul) using astrometry from spatial scanning WFC3 on HST. Observations were obtained at 6 month intervals over 4 years. The distances are 1.7--3.6 kpc with a mean precision 45 microarcseconds best 29 (SNR = 14). accuracy the parallaxes is demonstrated through independent analyses >100 reference stars. This raises to number significant measurements, 8 this...
Abstract We present Hubble Space Telescope (HST) photometry of 17 Cepheids in open clusters and their cluster mean parallaxes from Gaia EDR3. These are more precise than those individual ( G < 8 mag) previously used to measure the constant because they derived an average >300 stars per cluster. Cluster also have smaller systematic uncertainty lie range > 13 where parallax calibration is most comprehensive. Cepheid employed period–luminosity relation was measured using same HST...
ABSTRACT We present a high-precision measurement of the parallax for 12-day Cepheid SS Canis Majoris, obtained via spatial scanning with Wide Field Camera 3 (WFC3) on Hubble Space Telescope (HST) . Spatial enables astrometric measurements precision 20–40 μ as, an order magnitude better than pointed observations. CMa is second targeted HST and first sample 18 long-period (≳10 days) Cepheids selected in to improve calibration their period–luminosity relation eventually permit determination...
ABSTRACT We have investigated the possibilities to quantify how much stars move in Milky Way disc due diffuse processes (blurring) and influences from spiral arms bar (churning). assume that formation radius of a star can be inferred if we know its elemental abundances age metallicity profile interstellar medium at time star’s formation. use data for red giant branch APOGEE DR14, parallaxes Gaia, stellar ages based on C N abundances. In our sample, find half experienced some sort radial...