Detecting Solar Activity Signatures in High-Resolution Spectra

At Penn State, we are using high-resolution solar spectra in conjunction with solar satellite data to determine what parts of spectra are sensitive to various aspects of Solar activity.

pilot study lead by Nicole Hao (a student I supervised): Detecting and Classifying Flares in High-resolution Solar Spectra with Supervised Machine Learning

Substellar Accretion

We are using HST and JWST to look at young, accreting sub-stellar objects to understand how they form.

papers on Cha 1107-7626:

Flagg+2025, Detection of Hydrocarbons in the Disk around an Actively Accreting Planetary-mass Object

Almendros-Abad+2025, Discovery of an Accretion Burst in a Free-floating Planetary-mass Object

paper on J0844: Panzera+2025, Accretion Properties of the Young Brown Dwarf 2MASS J08440915-7833457

Characterizing Exoplanet Atmospheres with High-Resolution, Optical Transmission Spectra

ExoGemS is using spectra from Gemini-GRACES to characterize exoplanets with a wide range of properties. One highlight from our survey is the detection of CrH in WASP-31b.

paper: https://ui.adsabs.harvard.edu/abs/2023ApJ…953L..19F/abstract

twitter thread: https://twitter.com/lauraflaggastro/status/1679488708473651201

a student I supervised, Yasmine Meziani, lead another paper: The Effect of Offsets from True Orbital Parameters on Exoplanet High-resolution Transmission Spectra

Characterizing Young Exoplanets

We used high-resolution spectroscopy from IGRINS to detect CO in the atmosphere of CI Tau b, a planet initially discovered by the radial velocity method in 2016. Our detection confirms the existence of CI Tau b, making it the youngest confirmed hot Jupiter. It is also the first planet around a T Tauri star with a dynamic mass measurement.

Paper: https://ui.adsabs.harvard.edu/abs/2019ApJ…878L..37F/abstract

Gas Dispersal Timescales in Circumstellar Disks

Planet formation hinges on the gas present in the disk. We have looked for (and found!) small amounts of warm molecular hydrogen in disks previously thought to not have warm gas.

Paper on AU Mic: https://ui.adsabs.harvard.edu/abs/2022ApJ…934….8F/abstract

twitter thread on AU Mic: https://twitter.com/lauraflaggastro/status/1534218411387002881

Paper on TWA 7: https://ui.adsabs.harvard.edu/abs/2021ApJ…921…86F/abstract

poster: https://lauraflagg.github.io/files/coolstars21_poster_new.pdf