_version_ 1866929385714483200
author 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.
author_facet 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.
contents 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-$σ$ 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.
format Preprint
id arxiv_https___arxiv_org_abs_2406_09595
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle HD 21520 b: a warm sub-Neptune transiting a bright G dwarf
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.
Earth and Planetary Astrophysics
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-$σ$ 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.
title HD 21520 b: a warm sub-Neptune transiting a bright G dwarf
topic Earth and Planetary Astrophysics
url https://arxiv.org/abs/2406.09595