The compositions of rocky planets in close-in orbits tend to be earth-like

Hundreds of exoplanets between 1 and 1.8 times the size of Earth have been discovered on close-in orbits. However, these planets show such a diversity in densities that some appear to be made entirely of iron, while others appear to host gaseous envelopes. To test this diversity in composition, we u...

Full description

Saved in:
Bibliographic Details
Main Authors: Brinkman, Casey (Author) , Weiss, Lauren M. (Author) , Huber, Daniel (Author) , Lee, Rena A. (Author) , Kolecki, Jared (Author) , Tenn, Gwyneth (Author) , Zhang, Jingwen (Author) , Narayanan, Suchitra (Author) , Polanski, Alex S. (Author) , Dai, Fei (Author) , Bean, Jacob L. (Author) , Beard, Corey (Author) , Brady, Madison (Author) , Brodheim, Max (Author) , Brown, Matt (Author) , Chontos, Ashley (Author) , Deich, William (Author) , Edelstein, Jerry (Author) , Fulton, Benjamin J. (Author) , Giacalone, Steven (Author) , Gibson, Steven R. (Author) , Gilbert, Gregory J. (Author) , Halverson, Samuel (Author) , Handley, Luke (Author) , Hill, Grant M. (Author) , Holcomb, Rae (Author) , Holden, Bradford (Author) , Householder, Aaron (Author) , Howard, Andrew W. (Author) , Isaacson, Howard (Author) , Kaye, Stephen (Author) , Laher, Russ R. (Author) , Lanclos, Kyle (Author) , Ong, J. M. Joel (Author) , Payne, Joel (Author) , Petigura, Erik A. (Author) , Pidhorodetska, Daria (Author) , Poppett, Claire (Author) , Roy, Arpita (Author) , Rubenzahl, Ryan (Author) , Saunders, Nicholas (Author) , Schwab, Christian (Author) , Seifahrt, Andreas (Author) , Shaum, Abby P. (Author) , Sirk, Martin M. (Author) , Smith, Chris (Author) , Smith, Roger (Author) , Stefánsson, Guđmundur (Author) , Stürmer, Julian (Author) , Thorne, Jim (Author) , Turtelboom, Emma V. (Author) , Tyler, Dakotah (Author) , Valliant, John (Author) , Van Zandt, Judah (Author) , Walawender, Josh (Author) , Yee, Samuel W. (Author) , Yeh, Sherry (Author) , Zink, Jon (Author)
Format: Article (Journal)
Language:English
Published: 2025 August
In: The astronomical journal
Year: 2025, Volume: 170, Issue: 2, Pages: 1-16
ISSN:1538-3881
DOI:10.3847/1538-3881/ade677
Online Access:Verlag, kostenfrei, Volltext: https://doi.org/10.3847/1538-3881/ade677
Verlag, kostenfrei, Volltext: https://iopscience.iop.org/article/10.3847/1538-3881/ade677
Get full text
Author Notes:Casey L. Brinkman, Lauren M. Weiss, Daniel Huber, Rena A. Lee, Jared Kolecki, Gwyneth Tenn, Jingwen Zhang, Suchitra Narayanan, Alex S. Polanski, Fei Dai, Jacob L. Bean, Corey Beard, Madison Brady, Max Brodheim, Matt Brown, Ashley Chontos, William Deich, Jerry Edelstein, Benjamin J. Fulton, Steven Giacalone, Steven R. Gibson, Gregory J. Gilbert, Samuel Halverson, Luke Handley, Grant M. Hill, Rae Holcomb, Bradford Holden, Aaron Householder, Andrew W. Howard, Howard Isaacson, Stephen Kaye, Russ R. Laher, Kyle Lanclos, J.M. Joel Ong, Joel Payne, Erik A. Petigura, Daria Pidhorodetska, Claire Poppett, Arpita Roy, Ryan Rubenzahl, Nicholas Saunders, Christian Schwab, Andreas Seifahrt, Abby P. Shaum, Martin M. Sirk, Chris Smith, Roger Smith, Guđmundur Stefánsson, Julian Stürmer, Jim Thorne, Emma V. Turtelboom, Dakotah Tyler, John Valliant, Judah Van Zandt, Josh Walawender, Samuel W. Yee, Sherry Yeh, and Jon Zink
Description
Summary:Hundreds of exoplanets between 1 and 1.8 times the size of Earth have been discovered on close-in orbits. However, these planets show such a diversity in densities that some appear to be made entirely of iron, while others appear to host gaseous envelopes. To test this diversity in composition, we update the masses of five rocky exoplanets (HD 93963 A b, Kepler-10 b, Kepler-100 b, Kepler-407 b, and TOI-1444 b) and present the confirmation of a new planet (TOI-1011) using 187 high-precision radial velocities from Gemini/MAROON-X and Keck/KPF. Our updated planet masses suggest compositions closer to that of Earth than previous literature values for all planets in our sample. In particular, we report that two previously identified “super-Mercuries” (Kepler-100 b and HD 93963 A b) have lower masses that suggest less iron-rich compositions. We then compare the ratio of iron to rock-building species with the abundance ratios of those elements in their host stars. These updated planet compositions do not suggest a steep relationship between planet and host star compositions, contradictory to previous results, and suggest that planets and host stars have similar abundance ratios.
Item Description:Online verfügbar: 23. Juli 2025
Gesehen am 17.12.2025
Physical Description:Online Resource
ISSN:1538-3881
DOI:10.3847/1538-3881/ade677