Fields spanning the full sky.
Overview
The MDW hydrogen-alpha (Hα) Sky Survey is a full-sky imaging survey in the narrowband Hα wavelength (656.3 nm), with the goal of producing a deep, high-resolution Hα view of the night sky. The survey operates using custom-modified Astro-Physics 130 mm f/6.3 refractors, an FLI ProLine 16803 CCD camera, and a 3 nm Astrodon Hα filter. Survey observations began in 2016, with observing completion confirmed in 2026, marking the ten-year span of the program.
History: The survey was founded by David Mittelman, Dennis di Cicco, and Sean Walker, with continuing support from the Michele and David Mittelman Family Foundation. Click here to learn more about the survey and its origins. Beginning in 2022, the Columbia team joined the project to support data analysis, reduction, calibration, and public dissemination.
Observation: AP1 and AP2 have been deployed in New Mexico since the beginning of the survey. In 2023, AP3 was added in Chile to extend coverage to southern exposures, and AP1 and AP2 later joined it in completing the southern half of the sky.
Data Release: DR0, released in January 2024, covered the region surrounding Orion as the initial public data release. DR1, released in January 2025, expanded coverage to the entire northern sky. DR2 is planned for the end of 2026 and is intended to provide the first full-sky public release.
Key Specifications
Approximate angular extent of each field.
Nominal sequence and total integration per field.
Image resolution across the survey products.
Sampling scale for the reduced images.
Narrowband Hα science band.
Astro-Physics refractor with FLI ProLine 16803 CCD.
Coordinated between NM and Chile.
Survey Progress Map
Click a field to reveal its information and status.
MDW DR1 data in the northern hemisphere, overlay with WHAM released data in the southern hemisphere. Citation: Haffner et al. 2003, ApJS, 149, 405-422.
Survey Progress Animation
Acknowledgements
Funding for the MDW Survey Project has been provided by the Michele and David Mittelman Family Foundation. David R. Mittelman, Dennis di Cicco, and Sean Walker are founding members of the survey and made possible the acquisition and reduction of the data. The Columbia University Astronomy Department is responsible for the final data reduction, calibration, and dissemination of the survey data.