{"OA_place":"publisher","file_date_updated":"2024-10-21T11:05:11Z","date_updated":"2024-10-21T11:06:04Z","publisher":"IOP Publishing","scopus_import":"1","citation":{"ista":"Oza AV, Seidel JV, Hoeijmakers HJ, Unni A, Kesseli AY, Schmidt CA, Sivarani T, Bello-Arufe A, Gebek A, Meyer Zu Westram M, Sousa SG, Lopes RMC, Hu R, De Kleer K, Fisher C, Charnoz S, Baker AD, Halverson SP, Schneider NM, Psaridi A, Wyttenbach A, Torres Rodriguez S, Bhatnagar I, Johnson RE. 2024. Redshifted sodium transient near exoplanet transit. Astrophysical Journal Letters. 973(2), L53.","apa":"Oza, A. V., Seidel, J. V., Hoeijmakers, H. J., Unni, A., Kesseli, A. Y., Schmidt, C. A., … Johnson, R. E. (2024). Redshifted sodium transient near exoplanet transit. <i>Astrophysical Journal Letters</i>. IOP Publishing. <a href=\"https://doi.org/10.3847/2041-8213/ad6b29\">https://doi.org/10.3847/2041-8213/ad6b29</a>","ama":"Oza AV, Seidel JV, Hoeijmakers HJ, et al. Redshifted sodium transient near exoplanet transit. <i>Astrophysical Journal Letters</i>. 2024;973(2). doi:<a href=\"https://doi.org/10.3847/2041-8213/ad6b29\">10.3847/2041-8213/ad6b29</a>","ieee":"A. V. Oza <i>et al.</i>, “Redshifted sodium transient near exoplanet transit,” <i>Astrophysical Journal Letters</i>, vol. 973, no. 2. IOP Publishing, 2024.","short":"A.V. Oza, J.V. Seidel, H.J. Hoeijmakers, A. Unni, A.Y. Kesseli, C.A. Schmidt, T. Sivarani, A. Bello-Arufe, A. Gebek, M. Meyer Zu Westram, S.G. Sousa, R.M.C. Lopes, R. Hu, K. De Kleer, C. Fisher, S. Charnoz, A.D. Baker, S.P. Halverson, N.M. Schneider, A. Psaridi, A. Wyttenbach, S. Torres Rodriguez, I. Bhatnagar, R.E. Johnson, Astrophysical Journal Letters 973 (2024).","chicago":"Oza, Apurva V., Julia V. Seidel, H. Jens Hoeijmakers, Athira Unni, Aurora Y. Kesseli, Carl A. Schmidt, Thirupathi Sivarani, et al. “Redshifted Sodium Transient near Exoplanet Transit.” <i>Astrophysical Journal Letters</i>. IOP Publishing, 2024. <a href=\"https://doi.org/10.3847/2041-8213/ad6b29\">https://doi.org/10.3847/2041-8213/ad6b29</a>.","mla":"Oza, Apurva V., et al. “Redshifted Sodium Transient near Exoplanet Transit.” <i>Astrophysical Journal Letters</i>, vol. 973, no. 2, L53, IOP Publishing, 2024, doi:<a href=\"https://doi.org/10.3847/2041-8213/ad6b29\">10.3847/2041-8213/ad6b29</a>."},"intvolume":"       973","license":"https://creativecommons.org/licenses/by/4.0/","article_number":"L53","ddc":["520"],"abstract":[{"text":"Neutral sodium (Na i) is an alkali metal with a favorable absorption cross section such that tenuous gases are easily illuminated at select transiting exoplanet systems. We examine both the time-averaged and time-series alkali spectral flux individually, over 4 nights at a hot Saturn system on a ∼2.8 day orbit about a Sun-like star WASP-49 A. Very Large Telescope/ESPRESSO observations are analyzed, providing new constraints. We recover the previously confirmed residual sodium flux uniquely when averaged, whereas night-to-night Na i varies by more than an order of magnitude. On HARPS/3.6 m Epoch II, we report a Doppler redshift at vΓ,NaD = + 9.7 ± 1.6 km s−1 with respect to the planet's rest frame. Upon examining the lightcurves, we confirm night-to-night variability, on the order of ∼1%–4% in NaD, rarely coinciding with exoplanet transit, not readily explained by stellar activity, starspots, tellurics, or the interstellar medium. Coincident with the ∼+10 km s−1 Doppler redshift, we detect a transient sodium absorption event dFNaD/F⋆ = 3.6% ± 1% at a relative difference of ΔFNaD(t) ∼ 4.4% ± 1%, lasting ΔtNaD ≳ 40 minutes. Since exoplanetary alkali signatures are blueshifted due to the natural vector of radiation pressure, estimated here at roughly ∼−5.7 km s−1, the radial velocity is rather at +15.4 km s−1, far larger than any known exoplanet system. Given that the redshift magnitude vΓ is in between the Roche limit and dynamically stable satellite orbits, the transient sodium may be a putative indication of a natural satellite orbiting WASP-49 A b.","lang":"eng"}],"author":[{"full_name":"Oza, Apurva V.","first_name":"Apurva V.","last_name":"Oza"},{"last_name":"Seidel","first_name":"Julia V.","full_name":"Seidel, Julia V."},{"first_name":"H. Jens","last_name":"Hoeijmakers","full_name":"Hoeijmakers, H. Jens"},{"full_name":"Unni, Athira","first_name":"Athira","last_name":"Unni"},{"full_name":"Kesseli, Aurora Y.","last_name":"Kesseli","first_name":"Aurora Y."},{"full_name":"Schmidt, Carl A.","last_name":"Schmidt","first_name":"Carl A."},{"first_name":"Thirupathi","last_name":"Sivarani","full_name":"Sivarani, Thirupathi"},{"full_name":"Bello-Arufe, Aaron","last_name":"Bello-Arufe","first_name":"Aaron"},{"full_name":"Gebek, Andrea","first_name":"Andrea","last_name":"Gebek"},{"full_name":"Meyer Zu Westram, Moritz","last_name":"Meyer Zu Westram","first_name":"Moritz"},{"last_name":"Sousa","first_name":"Sérgio G.","full_name":"Sousa, Sérgio G."},{"first_name":"Rosaly M.C.","last_name":"Lopes","full_name":"Lopes, Rosaly M.C."},{"last_name":"Hu","first_name":"Renyu","full_name":"Hu, Renyu"},{"full_name":"De Kleer, Katherine","last_name":"De Kleer","first_name":"Katherine"},{"full_name":"Fisher, Chloe","first_name":"Chloe","last_name":"Fisher"},{"full_name":"Charnoz, Sébastien","first_name":"Sébastien","last_name":"Charnoz"},{"first_name":"Ashley D.","last_name":"Baker","full_name":"Baker, Ashley D."},{"full_name":"Halverson, Samuel P.","first_name":"Samuel P.","last_name":"Halverson"},{"full_name":"Schneider, Nick M.","last_name":"Schneider","first_name":"Nick M."},{"last_name":"Psaridi","first_name":"Angelica","full_name":"Psaridi, Angelica"},{"last_name":"Wyttenbach","first_name":"Aurélien","full_name":"Wyttenbach, Aurélien"},{"full_name":"Torres Rodriguez, Santiago","id":"a8df4360-4328-11ee-8f1a-e502d0c83fc2","orcid":"0000-0002-3150-8988","last_name":"Torres Rodriguez","first_name":"Santiago"},{"first_name":"Ishita","last_name":"Bhatnagar","full_name":"Bhatnagar, Ishita"},{"full_name":"Johnson, Robert E.","last_name":"Johnson","first_name":"Robert E."}],"_id":"18306","tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"volume":973,"year":"2024","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","article_processing_charge":"Yes","quality_controlled":"1","DOAJ_listed":"1","language":[{"iso":"eng"}],"file":[{"creator":"dernst","date_updated":"2024-10-21T11:05:11Z","relation":"main_file","success":1,"access_level":"open_access","file_id":"18456","content_type":"application/pdf","file_name":"2024_AstrophysicalJourn_Oza.pdf","date_created":"2024-10-21T11:05:11Z","file_size":1249747,"checksum":"23eea2a6a0519694a84998957ad7b7fb"}],"doi":"10.3847/2041-8213/ad6b29","has_accepted_license":"1","external_id":{"arxiv":["2409.19844"]},"OA_type":"gold","date_published":"2024-10-01T00:00:00Z","publication_identifier":{"issn":["2041-8205"],"eissn":["2041-8213"]},"article_type":"original","publication":"Astrophysical Journal Letters","oa_version":"Published Version","month":"10","status":"public","date_created":"2024-10-13T22:01:49Z","oa":1,"day":"01","issue":"2","title":"Redshifted sodium transient near exoplanet transit","publication_status":"published","acknowledgement":"The research described in this Letter was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics Space Administration, © 2024. California Institute of Technology. Government sponsorship acknowledged. A.V.O. and J.V.S. thank M. Lendl for constraints and discussions on the mass of WASP-49 A b. S.G.S acknowledges the support from FCT through Investigador FCT contract nr. CEECIND/00826/2018 and POPH/FSE (EC).","department":[{"_id":"LiBu"}],"type":"journal_article"}