Planets embedded in disks
Although our Sun dominates the mass of the Solar System, it is Jupiter that is in charge of the angular momentum in our Solar System. Similarly, giant planets at more than 5 au from their host stars could dominate the angular momentum of planetary systems. Such planets, when they are young and self-luminous, are best accessible using high-contrast imaging.
Despite hundreds of night spent on the quest for such planets (e.g., Gemini Planet Imager [GPI] on the Gemini Observatory, see Nielsen et al. 2019; Spectro-Polarimetric High-contrast Exoplanet REsearch [SPHERE] on the Very Large Telescope [VLT], see Vigan et al. 2021; NIRC2 Vortex Coronagraph on the Keck Observatory, Wallack et al. 2022), only a handful of them are imaged. In the meantime, there are nearly a hundred of circumstellar disks discovered in these surveying efforts. Theoretical and hydrosimulation studies show that these sites are the places that planets exist. My effort has been trying to pull our such planets -- the planets that are embedded in disks.
1. Foundation: total intensity imaging of PDS 70 c
Direct imaging of a protoplanetary disk system -- the PDS 70 system. This system is the first and only system which shows ongoing planet formation (Keppler et al. 2018), planet-disk interaction (Bae et al. 2019), with two planets (Haffert et al. 2019) and exo-moon formation (Benisty et al. 2021). These aspects make PDS 70 the ideal space laboratory to test such theories, and inform planet formation and planet-disk interaction. Although PDS 70 b is discovered back in 2018, the fact that PDS 70 c colocates with the disk makes it hard to verify its existence -- until when we are in (Wang, Ginzburg, Ren et al. 2020; AJ, arxiv, ADS).
Technical highlight: I modeled the PDS 70 disk to reveal the planet c (while ignoring the contribution from c) using the DebrisDiskFM framework constructed here.
Scientific highlight: we imaged the PDS 70 system in Keck/NIRC2 L'-band, and performed an astrometric and spectral analysis for the two planets. See Keck, NSF, etc. webpages.
Scientific implications: this effort paves the way for imaging planets that are embedded in disks.
Project timescale: 2019 October to 2020 March.
2. Application: planet imaging around HD 34282
Are there more PDS 70 c–like planets? We applied the technique to HD 34282, a protoplanetary disk system that shows evidence of planet-disk interaction, to find out. As the research project advisor, I recruited and worked with Juan Quiroz who modeled the observed disk structure for HD 34282 using DebrisDiskFM.
Technical highlight: Juan modeled the HD 3482 disk in Keck/NIRC2 L'-band to reveal possible planets as a blind-search of such planets.
Scientific highlight: After comparing with SPHERE data, we determined that a blob in the NIRC2 data is infact an inner disk. Although we do not find hidden planets, we do obtain better planet-detection limits after disk modeling.
Scientific implications: Despite a non-detection, our new limits can better constrain planet formation and planet-disk interaction models.
Project timescale: 2021 May to 2021 December.
3. Ongoing efforts: targeted search of planets that are embedded in disks.
Timescale: 2022 and beyond.