Colloquium by Jackie Faherty, AMNH
While the future of comparative planetology lies in obtaining direct spectroscopic measurements of distant giant planets, they remain an observational challenge even for the James Webb Space Telescope (JWST). That said, JWST has recently been used to directly detect two temperate 250K - 275K gas giant worlds orbiting solar type stars (Epsilon Ind and 14 Her). There are also a handful of other JWST GO programs that are targeting cold worlds directly but the results are pending. While the detection of temperate worlds demands a celebration of JWST’s capabilities, these measurements are challenging, high risk and – at this point – only photometric detections. Interpreting planets’ photometric and low-resolution data will rely heavily on atmospheric model predictions in a largely untested regime. Comparable high-resolution spectral anchors are needed. Luckily, cold brown dwarfs (500K > Teff > 250K) are isolated and bright enough that they make ideal spectral targets that can be studied as a population with the precision of JWST TODAY. Our team has been gathering all archival data on ultracool dwarfs obtained thus far with any NIRSpec or MIRI set-up to create near complete spectral energy distributions (SEDs) for every cold brown dwarf observed to date (~14 objects). These SED’s can be used to probe (1) pressure-dependent abundances for key tracers of clouds, (2) disequilibrium chemistry, (3) vertical mixing, (4) auroral processes, and (5) formation pathway. On top of archival data, our team has been awarded a JWST cycle 4 large GO program to fill in the coldest ultra cool dwarf temperature bins with high resolution spectral data. In this talk I will present the state of this “cold worlds spectral library” using and the scientific advancements we have made thus far in understanding atmosphere diversity outside the solar system.
Cookies will be available, starting at 3:45.
Host: Marcel Agüeros