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IR STIG Webinar

Infrared Science and Technology Integration Group

DATE

Nov 06, 2023

TIME

3:00 pm EST

COMMUNITY

IR STIG

TYPE

Webinar

Characterizing the Near-infrared Spectra of Flares from TRAPPIST-1 During JWST Transit Spectroscopy Observations

Ward Howard (University of Colorado Boulder | CASA)

We present the first analysis of near-infrared JWST spectroscopy of stellar flares from TRAPPIST-1 during transits of rocky exoplanets. Four flares were observed with NIRISS and NIRSpec during transit spectroscopy observations of TRAPPIST-1b, f, and g. Flares emit across the entire electromagnetic spectrum and must be considered as a key source of stellar contamination. Although not previously observed at wavelengths of 1-5µm, continuum emission is expected to be the dominant source of flare contamination. We strongly detect continuum in all four flares across the wavelength range of the instruments. We also characterize the He I infrared triplet and Paschen and Brackett series lines and discover a reversed Paschen decrement from Pα-Py. We model the NIR flare emission with the non-LTE RADYN code to explore the relative sizes of the kernel and flare ribbon. The degree of flare contamination is quantified as a function of flare size and wavelength, with contamination levels at 2µm of 2100±400 and 500±450 ppm observed for the TRAPPIST-1f and b transits, respectively. We model the line and continuum emission of the flares to discover that up to 80% of flare contamination can be removed, with mitigation most effective from 1-2.4µm. Our results suggest flare mitigation is a viable pathway to increase the scientific impact of transit observations of small planets around active stars.

An Exoplanet Hunting & Characterization Spectrograph for the Giant Magellan Telescope

Colby Jurgenson (Center for Astrophysics | Harvard & Smithsonian)

The GMT-Consortium Large Earth Finder (G-CLEF) is a fiber-fed, optical echelle spectrograph (350 to 950 nm) that will be a first light instrument for the Giant Magellan Telescope (GMT). G-CLEF is a general-purpose echelle spectrograph (23k ≤ R ≤ 110k) with precision radial velocity (PRV) capability. The PRV goal of 10 cm/sec is necessary for detection of Earth-sized exoplanets orbiting Solar-type stars in their habitable zone. This imposes challenging stability requirements on the spectrograph optical performance and optomechanical support structure especially when considering the instrument’s operational environment. This presentation will provide an overview of G-CLEF and the current assembly, integration, and testing activities that have begun to take place. An emphasis will be placed on the 7-element “red” camera assembly testing as well as the assembly and alignment of the 3-facet R4 echelle grating.