# Resolving Doubles: Diameters of the Nearest Visual Binary Stars

> **NSF 01002526DB NSF RESEARCH & RELATED ACTIVIT** · Georgia State University Research Foundation, Inc. (GA) · $415,315

## Abstract

This project will precisely measure the sizes and temperatures of stars in nearby double-star systems. These stars are important, because they orbit each other but are far enough apart that they evolve just like single stars. Unlike many close binary stars, which can be distorted by each other's gravity, these wide pairs offer a clearer picture of how stars change over time. The team will use a special kind of telescope called an interferometer to measure the stars’ angular diameters, which will then be combined with information about their brightness and distance to calculate their physical sizes and temperatures. The project includes strong education and outreach components: high school students will learn about stars and build their own telescopes, and undergraduate and graduate students will receive hands-on training in modern astronomy. 

The research team will conduct a program of high-precision interferometric observations using the CHARA Array to measure angular diameters of stars in 14 nearby visual binary systems. The targets are selected to be spatially resolvable, wide enough to avoid tidal interactions, and have existing or emerging dynamical mass constraints. By combining angular diameters with bolometric fluxes and precise parallaxes, the project will derive effective temperatures and physical radii to within 2% precision for at least 24 stars across a broad range of masses and metallicities. This dataset will provide critical tests of modern stellar evoluti

## Key facts

- **NSF award ID:** 2511438
- **Awardee organization:** Georgia State University Research Foundation, Inc. (GA)
- **SAM.gov UEI:** MNS7B9CVKDN7
- **PI:** Russel J White
- **Primary program:** 01002526DB NSF RESEARCH & RELATED ACTIVIT
- **All programs:** THEORETICAL & COMPUTATIONAL ASTROPHYSICS, OBSERVATIONAL ASTRONOMY
- **Estimated total:** $415,315
- **Funds obligated:** $415,315
- **Transaction type:** Standard Grant
- **Period:** 09/01/2025 → 08/31/2028

## Primary source

NSF Award Search: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2511438

## Citation

> US National Science Foundation, Award 2511438, Resolving Doubles: Diameters of the Nearest Visual Binary Stars. Retrieved via AI Analytics 2026-06-09 from https://api.ai-analytics.org/grant/nsf/2511438. Licensed CC0.

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