PDS 70 is a young T Tauri star located about 370 light-years away in the constellation Centaurus. It is surrounded by a protoplanetary disk with a large gap extending from around 65 to 140 AU. Image also shows the PDS 70 cexoplanets.
Planetary System
- PDS 70b: A gas giant planet with a mass a few times that of Jupiter, orbiting at around 20.8 AU from the star. It has a temperature of around 1,200K. It is observationally confirmed to have its own circumplanetary disk.
- PDS 70c: Another gas giant planet with a mass around 7.5 Jupiter masses, orbiting at 34.3 AU in a near 1:2 orbital resonance with PDS 70b. Its radius is estimated to be around 2 Jupiter radii.
Protoplanetary Disk
- The disk has an inner cavity extending out to around 65 AU, with larger dust grains cleared out to 80 AU.
- Observations with ALMA have detected emission from 12 different molecular species (CO, H2CO, C2H, HCN, etc.) primarily originating from a bright ring outside the planets’ orbits, indicating a chemically rich environment.
- The molecular emission shows radial variations.
- The high C2H/13CO ratio and lower limits on N(CS)/N(SO) indicate the disk likely has a C/O ratio greater than 1.
- Water vapor has been detected in the inner disk region inside the cavity using JWST, indicating the conditions may be suitable for terrestrial planet formation.
The PDS 70 system provides a rare opportunity to study ongoing planet formation and the chemical links between a planet’s birth environment and its atmospheric composition.
References:
Water in the terrestrial planet-forming zone of the PDS 70 disk
Perotti, G., Christiaens, V., Henning, T. et al. Water in the terrestrial planet-forming zone of the PDS 70 disk. Nature 620, 516–520 (2023). https://doi.org/10.1038/s41586-023-06317-9
Accretion Properties of PDS 70b with MUSE*
Jun Hashimoto1,2,3, Yuhiko Aoyama4,5,6, Mihoko Konishi7, Taichi Uyama2,8,9, Shinsuke Takasao10, Masahiro Ikoma4,11, and Takayuki Tanigawa12
Published 2020 April 22 • © 2020. The Author(s). Published by the American Astronomical Society.
The Astronomical Journal, Volume 159, Number 5Citation Jun Hashimoto et al 2020 AJ 159 222DOI 10.3847/1538-3881/ab811e
https://iopscience.iop.org/article/10.3847/1538-3881/ab811e
The Chemical Inventory of the Planet-hosting Disk PDS 70
Stefano Facchini1, Richard Teague2, Jaehan Bae8,3, Myriam Benisty4,5, Miriam Keppler6, and Andrea Isella7
Published 2021 August 11 • © 2021. The American Astronomical Society. All rights reserved.
The Astronomical Journal, Volume 162, Number 3Citation Stefano Facchini et al 2021 AJ 162 99DOI 10.3847/1538-3881/abf0a4
https://iopscience.iop.org/article/10.3847/1538-3881/abf0a4
Circular Astronomy 