A data processing pipeline for the WINTER near-infrared surveyor using the $\texttt{mirar}$ framework
Year: 2026
Type: preprint
Abstract: We present the data reduction and transient detection pipeline for the Wide-field Infrared Transient Explorer (WINTER) surveyor and report its on-sky performance. The WINTER camera utilizes cost-effective InGaAs sensors as alternatives to traditional IR sensors, and is mounted on a dedicated 1-m robotic telescope at Palomar Observatory. The WINTER camera has six detectors producing a combined field-of-view of 1.2 sq. deg. equipped with y, J, and shortened-H bands. WINTER saw first light in June 2023 and has been operating robotically since. The WINTER data processing pipeline ($\texttt{winterdrp}$) has been implemented within the broader framework $\texttt{mirar}$: a modular, open-source $\texttt{python}$ package developed for realtime processing of images from time-domain surveys. $\texttt{winterdrp}$ performs end-to-end data processing implementing data reduction and image subtraction to go from raw dithered WINTER images to transient alerts in the $\texttt{avro}$ format, which are then sent to $\texttt{SkyPortal}$ for vetting and follow-up. During a year of observations in 2024, WINTER achieved J-band median 5-$σ$ depths ranging from $18.1-18.8$ mag (AB) on its six detectors in 960 second integrations as part of its survey, with an astrometric accuracy of $\approx0.2$ arcsec (a fifth of a pixel) and a detector-performance limited photometric accuracy ranging from $\approx0.09-0.18$ mag for its six detectors. We present early science results from WINTER, which include the identification of a stellar merger in M31, dust-enshrouded outbursting young stellar objects and classical novae in the Galactic plane, NIR followup of known supernovae, and multi-messenger follow-up of neutrinos, gravitational waves, fast X-ray transients and gamma-ray bursts.
Source: arXiv (Cornell University)
Authors: Karambelkar, Viraj, Stein, Robert, Frostig, Danielle, Hall, Saarah, Kasliwal, Mansi M., Ahumada, Tomás, Coughlin, Michael W., Culino, Thomas, De, Kishalay, Kishore, Sulekha, Laz, Theophile Jegou du, Lourie, Nathan P., Mo, Geoffrey, Mohan, Tanishk, Rose, Sam, Roulston, Benjamin R., Saikia, Aditya Pawan, Sheshadri, Mallika, Simcoe, Robert A., Soon, Jamie, Suresh, Aswin
Institutions: Columbia University, Center for Astrophysics Harvard & Smithsonian, Northwestern University, California Institute of Technology, Cerro Tololo Inter-American Observatory, Flatiron Institute, Massachusetts Institute of Technology, Carnegie Institution for Science, Carnegie Observatories, Indian Institute of Technology Bombay, Clarkson University, Australian National University
Language: English
Subfield: Instrumentation
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, National Aeronautics and Space Administration, Gordon and Betty Moore Foundation, Research Corporation for Science Advancement, California Institute of Technology, Space Telescope Science Institute, Australian Government, Flatiron Health, Division of Astronomical Sciences
Awards: G1452811138, Postdoctoral Fellowship: AAPF: The explosive origins of heavy elements: systematic searches for r-process sites with WINTER, MRI: Development of a Wide-Field Infrared Camera for Robotic Surveys of the Dynamic Astronomical Sky, Extending the Teach of Gravitational-Wave Detectors through Low Latency Data Products, Unmodeled Searches, and Detector Characterization, G3234290369, G433322167, DFG-NSF Physics: Maximizing the Science Return of Target of Opportunity Observations Connected to Compact Binary Mergers, G58316358, G6273510985, HDR Institute: Accelerated AI Algorithms for Data-Driven Discovery, G7692557364
OpenAlex ID: W7212252289