A team using the VLA Low‑band Ionosphere and Transient Experiment (VLITE) produced the most sensitive 340 MHz image of the Hubble Ultra Deep Field (HUDF) yet. Welcoming 20 hours of data, the map covers 4 deg² with an angular resolution of 8.8 × 3.8 arcseconds and a central noise level of 158 µJy beam⁻¹.

The survey catalogues 671 radio sources. After correcting for incompleteness with injection‑recovery simulations based on a model radio continuum population, the source counts reproduce the sub‑milliJansky population of star‑forming galaxies seen in other deep fields at the same frequency.

Repeated observations over 45 days, spaced 1.3 years apart, allow a search for variability on roughly one‑year timescales. Eleven single‑component sources show flux changes between 1–100 mJy, with modulation indices from 6 % to 40 %. Six of these sources have peaked spectra, characteristic of compact active galactic nuclei. Most variability matches predictions for refractive interstellar scintillation; the three sources with modulation above 30 % probably flare intrinsically.

The data also reveal a compact symmetric object identified in follow‑up VLBA imaging, demonstrating VLITE’s ability to uncover young radio AGN through low‑frequency variability studies.

Although the image noise displays a non‑Gaussian tail beyond 3σ and systematic calibration errors contribute a ~15 % flux uncertainty, the high‑quality map still reliably measures sub‑milliJansky sources and identifies variable AGN candidates.