#astronomy The Hubble Area Telescope As Cosmic-Ray Detector – Sky & Telescope
Depiction of Earth’s geomagnetic subject NASA The Hubble Area Telescope requires little or no introduction. For greater than three many years, the telescope has stood on the forefront of astronomical analysis, whereas its visually gorgeous pictures have served as a paragon of awe and inspiration. However all this time, Hubble has additionally been secretly performing
Depiction of Earth’s geomagnetic subject
The Hubble Area Telescope requires little or no introduction. For greater than three many years, the telescope has stood on the forefront of astronomical analysis, whereas its visually gorgeous pictures have served as a paragon of awe and inspiration.
However all this time, Hubble has additionally been secretly performing as a particle detector. And a great one at that, as a staff of scientists demonstrated in a pilot examine to look in The Astrophysical Journal (preprint accessible right here).
Energetic charged particles, or cosmic rays, populate each nook of the photo voltaic system. A near-constant circulation of galactic particles originates from supernova remnants (and the stellar cinders at their cores). The Solar additionally sheds energetic particles, principally protons, throughout photo voltaic flares and coronal mass ejections.
These cosmic rays wiggle and push their approach by means of the photo voltaic system beneath the affect of the magnetized photo voltaic wind. Many find yourself at Earth, the place they threaten astronauts, disrupt satellites, and have an effect on atmospheric chemistry.
Cosmic rays are each astronomer’s nightmare. Neither floor nor area telescopes are resistant to the barrage of the energetic particles, and when a particle travels by means of a digicam, it leaves a pointy and brilliant hint on the ensuing picture. For sure, astronomers attempt to take away this air pollution from their knowledge.
However now scientists have demonstrated that one particular person’s rubbish is one other’s treasure.
Hubble’s Treasure Trove
“The thought for this undertaking began 5 or 6 years in the past at a convention about area climate,” says Susana Deustua (Ars Metrologia, previously Area Telescope Science Institute), who led the examine. A global group of astronomers, particle physicists, and planetary scientists put their heads collectively and got here up with a plan. “Cosmic rays work together with the geomagnetic subject,” Deustua provides. “We all know that Hubble collects charged particles on its detector, subsequently we must always be capable of glean details about the sphere from Hubble.”
The staff dug into Hubble’s wealthy knowledge archive. They seemed for calibration pictures that have been notably well-suited for his or her plan and ended up with virtually 100,000 pictures collected over the previous 25 years.
Algorithms for locating and eradicating cosmic-ray traces from astronomical pictures have been round for many years. However moderately than merely eliminating the traces, the staff needed to study as a lot as potential in regards to the cosmic rays that triggered them. “For instance, we needed to know what number of pixels on the digicam every cosmic ray affected and the way a lot vitality the particle misplaced within the course of,” explains graduate scholar Nathan Miles (College of California), who’s first creator on the examine.
Miles developed software program to extract such info, utilizing cloud computing providers to hold out the time-demanding computations. His algorithm harvested greater than 1 billion cosmic rays from the pictures.
Map of cosmic ray traces in one of many Hubble’s pictures. Traces might have completely different shapes and have an effect on completely different variety of pixels on the digicam.
A Cosmic-ray Picture of Earth’s Magnetic Discipline
The outcomes present an essential proof of idea with encouraging outcomes. The cosmic ray properties from Hubble knowledge match these detected by the PAMELA experiment, a defunct particle detector in low-Earth orbit. The staff additionally noticed of their knowledge the South Atlantic Anomaly, the well-known dip within the Earth’s geomagnetic subject. And so they noticed the anticipated response of cosmic rays to the photo voltaic cycle.
Claudio Corti (College of Hawai‘i at Manoa), who was not concerned within the examine, was pleasantly stunned by the work. “There’s all the time curiosity in a greater understanding of the geomagnetic subject and the impact it has on the particle radiation for astronauts and electronics on the satellites,” he says. The information might show beneficial to know cosmic ray populations within the photo voltaic system.
The evaluation to date has solely scratched the floor. The staff is trying ahead to unleashing the complete energy of the info to higher perceive the relation between galactic cosmic rays, the Solar, and Earth’s atmosphere. “Considered one of our pursuits is to look if we are able to discover delicate secular modifications within the geomagnetic subject,” Deustua says. “We additionally need to make comparisons with geophysical observatories.”
Hubble’s uninterrupted monitoring of cosmic rays over 1 / 4 of a century properly enhances different cosmic ray detectors. “From one single-point measurement, it’s exhausting to get info on the worldwide area atmosphere,” Corti says. “The extra factors you’ve gotten, the higher it’s.”