0 Assigned ID: 3856 ----- Attempting Submission 1 (Fri Oct 21 22:09:18 GMT 2022) ----- Swapped two targets after instrument team approval. Removed visits 05 and 06, and replaced with visits 07 and 08. 1014601386 ----- Attempting Submission 1 (Thu Dec 29 21:40:38 GMT 2022) ----- ----- Attempting Submission 2 (Mon May 15 23:12:53 GMT 2023) ----- Revealing the Nature of Five Potential Bright Galaxies at z > 10 Galaxies at the earliest epoch of the Universe are excellent laboratories for the physics of galaxy formation. Using photometry in the 24deg^2 Spitzer-HETDEX Large Area Exploratory survey, we find 5 candidates of galaxies at z>10, characterized by a sharp discontinuity of emission at ~1.5 micron, indicative of a Lyman break at z>10. We propose observations using WFC3 F125W and F160W imaging to reveal the high redshift nature of the five promising z>10 galaxy candidates. The F125W imaging will be able to conclusively rule out a lower redshift model, while the F160W band imaging will constrain the location of the Lyman break. Confirmation of our candidates will challenge models of galaxy formation at high redshift. We will obtain F125W and F160W imaging for 5 candidate bright galaxies at z>10 to confirm the Lyman break and constrain their photometric redshift. For each target, we will observe with 1 visit of 1 orbit, splitting the orbit between F125W and F160W. We center the source at the optimal point using the "IR" aperture. We employ the "BLOB" dither pattern with a two pint "LINE" sub-dither pattern for each source, resulting in 4 exposures per band per source. We selected exposures with SPARS25 and NSAMP=12 or 13 based on experience in previous programs and in consultation with the contact scientist. PI Gene Leung is an expert on galaxy evolution at high redshift, and the indentification of high redshift galaxies using photometric selection. He is a member of the SHELA survey team and has led the extraction of photometry for the new SHELA photometric catalog. He also has extensive experience with SED modeling of galaxies at high redshift through studies of galaxy properties in the MOSDEF and HETDEX surveys. Co-I Steven Finkelstein is an expert on galaxy evolution at high redshift, including identifying galaxies from deep ground and space-based imaging and spectroscopic surveys, and studying their physical properties via SED fitting. His main interests involve studying the evolution of galaxy properties, reionization, and the onset of galaxy quenching. Co-I Micaela Bagley has extensive experience with observations and interpretations of Lyman break galaxies at high redshift. M. Bagley is also an expert in HST data reduction and is leading the NIRCam reduction efforts for the CEERS ERS Survey. Co-I Aaron Yung is an expert on using semi-analytic methods to model galaxy formation and cosmic reionization. He also creates predictions for observable and physical properties for high-z galaxies and AGN. Co-I Rachel Somerville is an expert on theoretical simulations of galaxy formation, with a focus on high redshift galaxies. She is the lead developer of the Santa Cruz semi-analytic modeling code. Co-I Seiji Fujimoto, Casey Papovich, Robin Ciardullo, Caryl Gronwall, Shardha Jogee, Rebecca Larson, Alexa Morales, Oscar A. Chavez Ortiz, Jennifer Lotz, Stephen Wilkins, Katherine Chworowsky and Eric Gawiser are experts on galaxy evolution. 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