Nearly 6000 exoplanets have been detected to date, showing a great diversity in planetary system architectures that is substantially advancing our knowledge of planet formation and evolution. However, the majority of these discoveries come from systems that have their birth environments dissipated, precluding the exploration of the early stages of planetary systems. In contrast, direct imaging of protoplanets – the most effective means to probe these formation stages – remains extremely rare, with less than 5 such planets imaged so far. Meanwhile, the images of over 100 circumstellar disks in the past decade hint the existence of such elusive protoplanets. The SPICES project is designed to bridge the gap between high quality direct imaging datasets and the current limitation of data analysis methods. By refining and advancing applied mathematical methods for astronomical imaging, SPICES remarks an interdisciplinary exploration on the earliest stages of planet formation.
To push the boundaries of planet formation through direct imaging, the SPICES project is built around two synergistic objectives that drive our quest to understand the genesis of planetary systems:
1. SAFFRON (Spiral Arm Formation From mOtion aNalysis) Survey: Illuminating Hidden Worlds
By re-imaging spiral features in protoplanetary disks, the SAFFRON survey is dedicated to unearthing the subtle signatures of hidden planets residing within circumstellar environments. With a temporal separation of nearly 5 years, we can extract spiral motion signals that suggest the presence of nascent planetary bodies. The results then guide targeted direct imaging follow-up, facilitating the imaging of the next protoplanets.
2. Spectroscopic Characterization of Circumstellar Disks: Decoding the Building Blocks' Mineralogy
The imaging of circumstellar disks at multiple wavelengths, i.e. spectroscopy, informs their mineralogical composition. With current high-contrast imaging data reduction facing inherent computational compromises, advanced data imputation techniques can provide authentic disk images. This can enable a precise characterization of dust properties and opens the possibility to detect water ice tracers—key indicators of water reservoirs that might foster Earth analogs. With a systematic extraction of spectroscopy for circumstellar disks, we can explore the compositional trends for the building blocks of planetary formation sites. This not only informs the bulk composition of potential planets, but also facilitates a full exploration of the integral field spectrograph instruments in current and future high-contrast imagers.
