http://arxiv.org/abs/2001.00954
We present $Spitzer$ 4.5$\mu$m 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 $1.220^{+0.073}{-0.063}R\oplus$ and orbits within its host star’s conservative habitable zone with a period of 37.42 days ($T_\mathrm{eq} \sim 269$ K). TOI-700 also hosts two small inner planets (R$b$=$1.044^{+0.065}{-0.063}R_\oplus$ & R$c$=$2.64^{+0.16}{-0.14}R_\oplus$) with periods of 9.98 and 16.05 days, respectively. Our $Spitzer$ observations confirm the 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. With an expected RV semi-amplitude of $\sim$80 cm/s, it may be possible to measure the mass of TOI-700 d using state-of-the-art radial velocity instruments.
J. Rodriguez, A. Vanderburg, S. Zieba, et. al.
Tue, 7 Jan 20
55/71
Comments: 13 Pages, 3 Figures, 2 Tables, Submitted to the AAS Journals (12/22/2019), Some revisions from minor referee report