Polarized (sub)millimetre emission from dust grains in circumstellar disks was initially thought to be because of grains aligned with the magnetic field1,2. However, higher-resolution multi-wavelength observations3–5 and improved models6–10 found that this polarization is dominated by self-scattering at shorter wavelengths (for example, 870 µm) and by grains aligned with something other than magnetic fields at longer wavelengths (for example, 3 mm). Nevertheless, the polarization signal is expected to depend on the underlying substructure11–13, and observations until now have been unable to resolve polarization in multiple rings and gaps. HL Tau, a protoplanetary disk located 147.3 ± 0.5 pc away14, is the brightest class I or class II disk at millimetre–submillimetre wavelengths. Here we show deep, high-resolution polarization observations of HL Tau at 870 µm, resolving polarization in both the rings and
City crews will strengthen the dam, upgrade the spillway and improve flood protection to protect against the effects of climate change, such as more intense storms.
This week is Drinking Water Week, an opportunity for residents in Hampton Roads to know about how they get safe drinking water, and where it comes from.
In 2016, Barack Obama, the U.S. president at the time, made a proclamation: he would expand the protection of the Papahānaumokuākea Marine National Monument, a stretch of ocean fringing the islands and atolls of the Northwestern Hawaiian Islands that native Hawaiians consider to be sacred. Ten years earlier, his predecessor, George W. Bush had protected […]