The young HD 73583 (TOI-560) planetary system: two 10-M mini-Neptunes transiting a 500-Myr-old, bright, and active K dwarf

O. Barragán, D. J. Armstrong, D. Gandolfi, I. Carleo, A. A. Vidotto, C. Villarreal D'Angelo, A. Oklopčić, H. Isaacson, D. Oddo, K. Collins, M. Fridlund, S. G. Sousa, C. M. Persson, C. Hellier, S. Howell, A. Howard, S. Redfield, N. Eisner, I. Y. Georgieva, D. DragomirD. Bayliss, L. D. Nielsen, B. Klein, S. Aigrain, M. Zhang, J. Teske, J. D. Twicken, J. Jenkins, M. Esposito, V. Van Eylen, F. Rodler, V. Adibekyan, J. Alarcon, D. R. Anderson, J. M. Akana Murphy, D. Barrado, S. C.C. Barros, B. Benneke, F. Bouchy, E. M. Bryant, R. P. Butler, J. Burt, J. Cabrera, S. Casewell, P. Chaturvedi, R. Cloutier, W. D. Cochran, J. Crane, I. Crossfield, N. Crouzet, K. I. Collins, F. Dai, H. J. Deeg, A. Deline, O. D.S. Demangeon, X. Dumusque, P. Figueira, E. Furlan, C. Gnilka, M. R. Goad, E. Goffo, F. Gutiérrez-Canales, A. Hadjigeorghiou, Z. Hartman, A. P. Hatzes, M. Harris, B. Henderson, T. Hirano, S. Hojjatpanah, S. Hoyer, P. Kabáth, J. Korth, J. Lillo-Box, R. Luque, M. Marmier, T. Močnik, A. Muresan, F. Murgas, E. Nagel, H. L.M. Osborne, A. Osborn, H. P. Osborn, E. Palle, M. Raimbault, G. R. Ricker, R. A. Rubenzahl, C. Stockdale, N. C. Santos, N. Scott, R. P. Schwarz, S. Shectman, M. Raimbault, S. Seager, D. Ségransan, L. M. Serrano, M. Skarka, A. M.S. Smith, J. Šubjak, T. G. Tan, S. Udry, C. Watson, P. J. Wheatley, R. West, J. N. Winn, S. X. Wang, A. Wolfgang, C. Ziegler

Research output: Contribution to journalArticlepeer-review


The study presents the discovery and characterization of two exoplanets observed by NASA's TESS (Transiting Exoplanet Survey Satellite) in the light curves of the young and bright star HD73583, also known as TOI-560. Extensive follow-up observations, including spectroscopic and photometric measurements from space and ground-based instruments, were conducted to confirm and understand the properties of this planetary system.

The star HD73583 is relatively young, estimated to be around 500 million years old, and exhibits activity with a rotational period of approximately 12.08 days. It has a mass of about 0.73 times that of the Sun and a radius of about 0.65 times that of the Sun.

The first planet, HD 73583 b, has an orbital period of about 6.4 days. It has a mass of approximately 10.2 times that of Earth and a radius of about 2.79 times that of Earth, resulting in a density of about 2.58 grams per cubic centimeter. This suggests that it likely has a solid core surrounded by a volatile envelope.

The second planet, HD 73583 c, has a longer orbital period of approximately 18.88 days. It has a mass of about 9.7 times that of Earth and a radius of about 2.39 times that of Earth, with a density of about 3.88 grams per cubic centimeter, again indicating a solid core with a volatile envelope.

Both planets are considered suitable candidates for future transmission spectroscopy studies due to their youth and the brightness of their host star. The study also suggests that ongoing atmospheric mass-loss is expected for both planets due to the intense stellar radiation they receive. Detecting signs of evaporating atmospheres composed of hydrogen and helium would be challenging but achievable with current and upcoming astronomical instruments.
Original languageEnglish
Pages (from-to)1606-1627
Number of pages22
JournalMonthly Notices of the Royal Astronomical Society
Issue number2
StatePublished - Aug 1 2022

ASJC Scopus Subject Areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


  • planets and satellites: individual: HD 73583 (TOI-560)
  • stars: activity
  • techniques: photometric
  • techniques: radial velocities

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