HD 21520 b: a warm sub-Neptune transiting a bright G dwarf
2024
Online
report
Zugriff:
We report the discovery and validation of HD 21520 b, a transiting planet found with TESS and orbiting a bright G dwarf (V=9.2, $T_{eff} = 5871 \pm 62$ K, $R_{\star} = 1.04\pm 0.02\, R_{\odot}$). HD 21520 b was originally alerted as a system (TOI-4320) consisting of two planet candidates with periods of 703.6 and 46.4 days. However, our analysis supports instead a single-planet system with an orbital period of $25.1292\pm0.0001$ days and radius of $2.70 \pm 0.09\, R_{\oplus}$. Three full transits in sectors 4, 30 and 31 match this period and have transit depths and durations in agreement with each other, as does a partial transit in sector 3. We also observe transits using CHEOPS and LCOGT. SOAR and Gemini high-resolution imaging do not indicate the presence of any nearby companions, and MINERVA-Australis and CORALIE radial velocities rule out an on-target spectroscopic binary. Additionally, we use ESPRESSO radial velocities to obtain a tentative mass measurement of $7.9^{+3.2}_{-3.0}\, M_{\oplus}$, with a 3-$\sigma$ upper limit of 17.7 $M_{\oplus}$. Due to the bright nature of its host and likely significant gas envelope of the planet, HD 21520 b is a promising candidate for further mass measurements and for atmospheric characterization.
Comment: Submitted to MNRAS
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HD 21520 b: a warm sub-Neptune transiting a bright G dwarf
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Autor/in / Beteiligte Person: | Nies, Molly ; Mireles, Ismael ; Bouchy, François ; Dragomir, Diana ; Nicholson, Belinda A. ; Eisner, Nora L. ; Sousa, Sergio G. ; Collins, Karen A. ; Howell, Steve B. ; Ziegler, Carl ; Hellier, Coel ; Addison, Brett ; Ballard, Sarah ; Bowler, Brendan P. ; Briceño, César ; Clark, Catherine A. ; Conti, Dennis M. ; Dumusque, Xavier ; Edwards, Billy ; Gnilka, Crystal L. ; Hobson, Melissa ; Horner, Jonathan ; Kane, Stephen R. ; Kielkopf, John ; Lavie, Baptiste ; Law, Nicholas ; Lendl, Monika ; Littlefield, Colin ; Liu, Huigen ; Mann, Andrew W. ; Mengel, Matthew W. ; Oddo, Dominic ; Okumura, Jack ; Palle, Enric ; Plavchan, Peter ; Psaridi, Angelica ; Santos, Nuno C. ; Schwarz, Richard P. ; Shporer, Avi ; Wittenmyer, Robert A. ; Wright, Duncan J. ; Zhang, Hui ; Watanabe, David ; Medina, Jennifer V. ; Villaseñor, Joel ; Ting, Eric B. ; Christiansen, Jessie L. ; Winn, Joshua N. ; Stassun, Keivan G. ; Seager, S. ; Latham, David W. ; Ricker, George R. |
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Veröffentlichung: | 2024 |
Medientyp: | report |
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