The First Habitable Zone Earth-Sized Planet From TESS II: Spitzer Confirms TOI-700 d

• Published in: The Astronomical Journal
• Main Authors: Rodriguez, Joseph E., Vanderburg, Andrew, Zieba, Sebastian, Kreidberg, Laura, Morley, Caroline V., Kane, Stephen R., Spencer, Alton, Quinn, Samuel N., Eastman, Jason D., Cloutier, Ryan, Huang, Chelsea X., Collins, Karen A., Mann, Andrew W., Gilbert, Emily, Schlieder, Joshua E., Quintana, Elisa V., Barclay, Thomas, Suissa, Gabrielle, Kopparapu, Ravi kumar, Dressing, Courtney D., Ricker, George R., Vanderspek, Roland K., Latham, David W., Seager, Sara, Winn, Joshua N., Jenkins, Jon M., Berta-Thompson, Zachory, Boyd, Patricia T., Charbonneau, David, Caldwell, Douglas A., Chiang, Eugene, Christiansen, Jessie L., Ciardi, David R., Colón, Knicole D., Doty, John, Gan, Tianjun, Guerrero, Natalia, Günther, Maximilian N., Lee, Eve J., Levine, Alan M., Lopez, Eric, Muirhead, Philip S., Newton, Elisabeth, Rose, Mark E., Twicken, Joseph D., Villaseñor, Jesus Noel
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Astronomical Society 2020
• Subjects: Exoplanets; Habitable planets; Habitable zone; Low mass stars; Antarctic observatories; Exoplanet astronomy; Exoplanet detection methods; Exoplanet systems; Antarctic; Kavli; Sagan; Antarc*
• Online Access: https://doi.org/10.3847/1538-3881/aba4b3

We present Spitzer 4.5 μm observations of the transit of TOI-700 d, a habitable-zone Earth-sized planet in a multiplanet system transiting a nearby M-dwarf star (TIC 150428135, 2MASS J06282325–6534456). TOI-700 d has a radius of 1.144^(+0.062)_(-0.061) R⊕ and orbits within its host star's conservative habitable zone with a period of 37.42 days (T_(eq) ~ 269 K). TOI-700 also hosts two small inner planets (R_b = 1.037^(+0.0065)_(-0.064) R⊕ and R_c = 2.65^(+0.16)_(-0.15) R⊕) with periods of 9.98 and 16.05 days, respectively. Our Spitzer observations confirm the Transiting Exoplanet Survey Satellite (TESS) detection of TOI-700 d and remove any remaining doubt that it is a genuine planet. We analyze the Spitzer light curve combined with the 11 sectors of TESS observations and a transit of TOI-700 c from the LCOGT network to determine the full system parameters. Although studying the atmosphere of TOI-700 d is not likely feasible with upcoming facilities, it may be possible to measure the mass of TOI-700 d using state-of-the-art radial velocity (RV) instruments (expected RV semiamplitude of ~70 cm sâ»Â¹). © 2020 The American Astronomical Society. Received 2019 December 20; revised 2020 May 22; accepted 2020 May 26; published 2020 August 14. A.V.'s work was performed under contract with the California Institute of Technology (Caltech)/Jet Propulsion Laboratory (JPL) funded by NASA through the Sagan Fellowship Program executed by the NASA Exoplanet Science Institute. M.N.G. acknowledges support from MIT's Kavli Institute as a Juan Carlos Torres Fellow. C.D.D. acknowledges support from the NASA TESS Guest Investigator Program through grant 80NSSC18K1583. E.D.L. is thankful for support from GSFC Sellers Exoplanet Environments Collaboration (SEEC), which is funded by the NASA Planetary Science Divisions Internal Scientist Funding Model. J.N.W. thanks the Heising-Simons Foundation for support. E.A.G. thanks the LSSTC Data Science Fellowship Program, which is funded by LSSTC, NSF Cybertraining grant #1829740, the ...