JWST COMPASS: NIRSpec/G395H Transmission Observations of the Super-Earth TOI-836b

We present two transit observations of the ∼870 K, 1.7 R ⊕ super-Earth TOI-836b with JWST NIRSpec/G395H, resulting in a 2.8–5.2 μ m transmission spectrum. Using two different reduction pipelines, we obtain a median transit depth precision of 34 ppm for Visit 1 and 36 ppm for Visit 2, leading to a combined precision of 25 ppm in spectroscopic channels 30 pixels wide (∼0.02 μ m). We find that the transmission spectrum from both visits is well fit by a zero-sloped line, by fitting zero-sloped and sloped lines as well as step functions to our data. Combining both visits, we are able to rule out atmospheres with metallicities