51. GJ 3929: High-precision Photometric and Doppler Characterization of an Exo-Venus and Its Hot, Mini-Neptune-mass Companion
- Author
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Corey Beard, Paul Robertson, Shubham Kanodia, Jack Lubin, Caleb I Cañas, Arvind F Gupta, Rae Holcomb, Sinclaire Jones, Jessica E Libby-Roberts, Andrea S J Lin, Suvrath Mahadevan, Guđmundur Stefánsson, Chad F Bender, Cullen H Blake, William D Cochran, Michael Endl, Mark Everett, Eric B Ford, Connor Fredrick, Samuel Halverson, Leslie Hebb, Dan Li, Sarah E Logsdon, Jacob Luhn, Michael W McElwain, Andrew J Metcalf, Joe P Ninan, Jayadev Rajagopal, Arpita Roy, Maria Schutte, Christian Schwab, Ryan C Terrien, John Wisniewski, and Jason T Wright
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Astronomy - Abstract
We detail the follow-up and characterization of a transiting exo-Venus identified by TESS, GJ 3929b (TOI-2013b), and its nontransiting companion planet, GJ 3929c (TOI-2013c). GJ 3929b is an Earth-sized exoplanet in its star’s Venus zone (Pb = 2.616272 ± 0.000005 days; Sb = 17.3+0.8-0.7 S⊕) orbiting a nearby M dwarf. GJ 3929c is most likely a nontransiting sub-Neptune. Using the new, ultraprecise NEID spectrometer on the WIYN 3.5 m Telescope at Kitt Peak National Observatory, we are able to modify the mass constraints of planet b reported in previous works and consequently improve the significance of the mass measurement to almost 4σ confidence (Mb = 1.75 ± 0.45 M⊕). We further adjust the orbital period of planet c from its alias at 14.30 ± 0.03 days to the likely true period of 15.04 ± 0.03 days, and we adjust its minimum mass to m sin i = 5.71 ± 0.92 M⊕. Using the diffuser-assisted ARCTIC imager on the ARC 3.5 m telescope at Apache Point Observatory, in addition to publicly available TESS and LCOGT photometry, we are able to constrain the radius of planet b to Rp = 1.09 ± 0.04 R⊕. GJ 3929b is a top candidate for transmission spectroscopy in its size regime (TSM = 14 ± 4), and future atmospheric studies of GJ 3929b stand to shed light on the nature of small planets orbiting M dwarfs.
- Published
- 2022
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