How Do You "See" a Magnetic Field You Can't Touch?
You look at starlight. Dust grains aligned by magnetic fields filter passing light just slightly, and that faint signature can reveal invisible fields stretching across galaxies.
Former KIPAC-affiliated researcher Mehrnoosh Tahani has proven a cost-effective way to capture it. Her project, DragonflyPol, transforms the Dragonfly Telephoto Array — 48 stacked Canon camera lenses — into a wide-field polarization camera. The team hand-calibrated 44 polarizing filters to sub-degree precision, then validated the system by measuring the polarization of the twilight sky itself, matching the predicted signal to within 1.6°.
DragonflyPol has already turned its lenses on the Perseus molecular cloud, galactic dust clouds, and nearby galaxies like M51 and M82, with much more observing time ahead.
A small grant, a big domino effect
The project traces back to a single KIPAC Innovation Grant, funded through the Kavli Foundation endowment. That early, flexible funding let Tahani test lenses, prove the concept, and launch international collaborations with researchers across Canada, Japan, and Europe. It also helped grow a team of postdocs, PhD students, and undergraduates, ultimately supporting her transition to a faculty position, where she continues this work today.
“This kind of research isn't always the flashiest, but mapping interstellar magnetic fields is essential to understanding how stars, planets, and galaxies form. Funding early-stage, interdisciplinary science — the kind that's hard to fund elsewhere — is exactly what makes breakthroughs like this possible,” said Tahani.
This is what donor support makes possible: a small, well-timed grant, and a project that goes from an idea at a conference to published results in the sky.
Read the paper: arxiv.org/pdf/2607.14258
