On-sky Demonstration of Subdiffraction-limited Astronomical Measurement Using a Photonic Lantern
TL;DR
Scientists developed a new way to see incredibly fine details in space using a single telescope that normally wouldn't be possible due to physical limits. They tested this technique on a star and successfully measured tiny movements and features in the hot gas around it with precision 50 times better than what should theoretically be achievable.
Abstract Resolving fine details of astronomical objects provides critical insights into their underlying physical processes. This drives in part the desire to construct ever-larger telescopes and interferometer arrays and to observe at shorter wavelengths to lower the diffraction limit of angular resolution. Alternatively, one can aim to overcome the diffraction limit by extracting more information from a single telescope’s aperture. A promising way to do this is spatial-mode-based imaging, which projects a focal-plane field onto a set of spatial modes before detection, retaining focal-plane phase information that is crucial at small angular scales but typically lost in intensity imaging. However, the practical implementation of mode-based imaging in astronomy from the ground has been challenged by atmospheric turbulence. Here, we present the first on-sky demonstration of a subdiffraction-limited mode-based measurement, using a photonic-lantern-fed spectrometer installed on the Subaru Coronagraphic Extreme Adaptive Optics instrument at the Subaru Telescope. We introduce a novel calibration strategy that mitigates time-varying wave-front error and misalignment effects, leveraging simultaneously recorded focal-plane images and using a spectral-differential technique that self-calibrates the data. Observing the classical Be star β CMi, we detect spectral-differential spatial signals and reconstruct images of its H α -emitting disk. We achieve an unprecedented H α photocenter precision of ∼50 μ as in about 10 minutes of observation with a single telescope, measuring the disk’s nearside–farside asymmetry for the first time. This work demonstrates the high precision, efficiency, and practicality of photonic mode-based imaging techniques in recovering subdiffraction-limited information, opening new avenues for high-angular-resolution spectroscopic studies in astronomy.
- 1Achieved subdiffraction-limited imaging using a photonic lantern device attached to the Subaru Telescope, overcoming traditional resolution limits
- 2Measured the photocenter of a star's hydrogen-alpha disk with unprecedented precision of ~50 microarcseconds in just 10 minutes
- 3Successfully detected and imaged asymmetry between the near and far sides of the gas disk around the Be star β CMi for the first time
- 4Developed a novel self-calibrating technique that corrects for atmospheric turbulence and instrument misalignment using spectral-differential methods
- 5Demonstrated that a single telescope can extract more detailed information than previously thought possible by preserving phase information typically lost in standard imaging
Single-minus gluon tree amplitudes are nonzero
Imagine tiny particles called gluons are like spinning tops. Their spin can be in one of two directions, which physicists call 'plus' or 'minus'. For decades, the rulebook seemed to say that you could never have a situation where just one gluon was spinning 'minus' and all the others were spinning 'plus' — that outcome was thought to be zero. This paper found a loophole. Under very specific, purely mathematical conditions that don't exist in our physical reality but are useful for calculations, this interaction can happen. The researchers wrote down the exact recipe for it, fixing a small but important detail in our fundamental rulebook for how the universe works.
Sub-part-per-trillion test of the Standard Model with atomic hydrogen
Scientists made an incredibly precise measurement of light emitted by hydrogen atoms that tested one of physics' most fundamental theories - the Standard Model - to an accuracy of 0.7 parts per trillion. This measurement also resolved a long-standing disagreement about the size of protons by confirming the smaller value found in previous experiments with exotic atoms.
Rock art from at least 67,800 years ago in Sulawesi
Imagine finding a spray-painted handprint on a cave wall. Over thousands of years, a thin, glassy layer of minerals, like limescale in a kettle, grew on top of it. Scientists used a high-tech laser to analyze that mineral layer. By measuring the natural radioactive decay of elements within it, they figured out the layer is about 71,600 years old. Since the handprint is underneath that layer, it must be at least that old, with the most conservative estimate being 67,800 years. This makes it one of the oldest pieces of art ever found and proves that the early humans who lived on this Indonesian island, who had to cross the ocean to get there, were creating symbolic art.
An interstellar energetic and non-aqueous pathway to peptide formation
Imagine you have a box of LEGO bricks, which are like the basic molecules of life called amino acids. To build anything, you need to snap them together. Scientists used to think you needed a puddle of liquid water to make the bricks 'click'. This experiment is like discovering you can snap the LEGOs together inside a freezer. The researchers took the simplest amino acid, froze it onto a dust grain like you'd find in space, and zapped it with energy that mimics cosmic radiation. They found that the amino acids linked up to form a two-brick chain, the first step towards building a protein. This means the essential first chains for life could be forming all over space and delivered to new planets by comets and asteroids.