Presentations by Nic Scott

chara_meeting_2024

Mar 08, 2024 46 0

CHARA intro

Jan 29, 2024 69 0

Copy of deck

Nov 16, 2023 131 0

chara-update

Oct 31, 2023 92 0

deck

Sep 29, 2023 102 0

CHARA meeting 2023

Feb 22, 2023 215 0

speckle_retreat

Jun 08, 2022 349 0

public talk-skype-a-scientist

Mar 28, 2022 442 0

Exoplanets & how to find them

Aug 02, 2021 554 0

Exoplanets & how to find them

Jun 15, 2020 758 0

The Impact of EMCCDs on Speckle Imaging

Speckle imaging produces diffraction-limited images from ground-based telescopes in the optical wavebands. While the technique dates back almost 50 years, recent advancements in detectors such as electron-multiplying CCDs (EMCCDs) have spawned a resurgence of this technique. The use of EMCCDs has greatly improved sensitivity and observing efficiency for speckle instruments. The high angular resolution provided by speckle imaging can discern blended binary system contamination and validate suspected exoplanets discovered by the Kepler, K2, and TESS transit surveys. Three speckle instruments have been built to this purpose: one at the WIYN telescope, one at Gemini-North, and one at Gemini-South. These instruments are supported by NASA's Exoplanet Program Office and available for the community via the proposal process for each telescope. Multiplicity can be determined along with separation, position angle, photometry, and contrast ratio in a single observation. The speckle instruments can observe over a hundred targets per night and resolve binary systems only tens of milli-arcseconds apart in two wavebands simultaneously. In this way speckle imaging can validate even small, rocky planets like TRAPPIST-1 and constrain exoplanet radii and density. Observing in multiple wavelengths may further characterize observed systems. Furthermore, the high-speed capabilities and sensitivity of EMCCDs opens up new regimes for time-series photometry of rapidly varying astronomical sources. Objectives: 1) A brief history of speckle interferometry 2) Why EMCCDs have revitalized speckle techniques 3) Current speckle projects and science 4) Other benefits and uses of EMCCDs with speckle imagers. 5) Obtain overview of Andor camera solutions for high speed astronomical imaging

Apr 09, 2020 1,080 0

Coffee & Cosmos

Feb 25, 2020 718 0

public talk

Oct 24, 2019 935 0

Alopeke training

Oct 11, 2019 749 0

The Role of Speckle Imaging in Exoplanet Characterization

The majority of all stars exist in multiple-star systems. This can lead to false detections of transiting exoplanets or assigning them underestimated radii. High angular resolution imaging provides a means to de-blend these systems along with providing separations, position angles, photometry, and contrast ratios. Speckle imaging, utilizing recent advancements in detector technology, has enabled new instruments that can produce diffraction-limited images from ground-based telescopes with great efficiency. Discerning blended binary systems removes a major source of contamination and allows the characterization suspected exoplanets discovered by the Kepler, K2, and TESS transit surveys. These observations confirm small, rocky planets like TRAPPIST-1 and constrain exoplanet radii and density. Observing in multiple wavelengths further characterizes observed systems, confirming which star the exoplanet orbits in blended systems. Some of the developments leading to this technique will be discussed, along with recent significant papers, ongoing speckle imaging programs, and prospects for the future.

Sep 11, 2019 726 0