_version_ 1866908902848724992
author Li, Yiting
Meyer, Michael R.
D'Angiolillo, Skylar
Kane, Stephen R.
Butler, R. Paul
Shectman, Stephen A.
Mamajek, Eric E.
Teske, Johanna
Lubin, Jack
Robertson, Paul
Christiansen, Jessie L.
Isaacson, Howard
Harada, Caleb K.
Holden, Bradford
Cochran, William D.
Endl, Michael
Burt, Jennifer
Becker, Juliette
Jankowski, Alyssa
Tuthill, Peter
Clark, Catherine A.
Roettenbacher, Rachael M.
Nielsen, Eric
Bendek, Eduardo
Tokadjian, Armen
Roberson, William
Kratter, Kaitlin M.
Bergin, Edwin
Osip, Dave
Crane, Jeffrey D.
Davis, Alex
Vasisht, Gautam
author_facet Li, Yiting
Meyer, Michael R.
D'Angiolillo, Skylar
Kane, Stephen R.
Butler, R. Paul
Shectman, Stephen A.
Mamajek, Eric E.
Teske, Johanna
Lubin, Jack
Robertson, Paul
Christiansen, Jessie L.
Isaacson, Howard
Harada, Caleb K.
Holden, Bradford
Cochran, William D.
Endl, Michael
Burt, Jennifer
Becker, Juliette
Jankowski, Alyssa
Tuthill, Peter
Clark, Catherine A.
Roettenbacher, Rachael M.
Nielsen, Eric
Bendek, Eduardo
Tokadjian, Armen
Roberson, William
Kratter, Kaitlin M.
Bergin, Edwin
Osip, Dave
Crane, Jeffrey D.
Davis, Alex
Vasisht, Gautam
contents At a distance of 5.1 pc, the 70 Oph AB binary star system is one of the most favorable targets for future direct imaging and astrometry missions surveying mature, terrestrial planets. We present new radial velocities (RVs) obtained with the Planet Finder Spectrograph (PFS) on the 6.5\,m Magellan II Clay Telescope in Chile. We collected 499 measurements of 70 Oph A and 334 measurements of 70 Oph B during 2023--2025. Combining these data with decades of archival RVs and astrometry, we derive an updated orbital solution for the binary and dynamical masses of $0.88 \pm 0.004\,M_\odot$ and $0.73 \pm 0.003\,M_\odot$ for the primary and secondary components, respectively. We find that the long-term RV variability of both components is consistent with stellar activity modulated by rotation periods, and we detect no coherent planetary signals in either component. We place upper limits on any planets orbiting in the plane of the binary. The 27 yr RV baseline for 70 Oph A excludes Jupiter-mass planets interior to 5 au and reaches a sensitivity of $0.3\,M_{\rm Jup}$ at 1 au or $0.5\,M_{\rm Jup}$ at 2 au. For 70 Oph B, with PFS data we rule out planets more massive than $0.25$--$0.3\,M_{\rm Jup}$ inside 0.5 au. We show that stable S-type orbits around 70 Oph A extend to $\sim2.5$ au, covering the habitable zone. Thus, Saturn-mass planets or smaller on stable orbits in the habitable zone of 70 Oph A are allowed. Overall, our results provide important guidance for future planet searches around this stellar system.
format Preprint
id arxiv_https___arxiv_org_abs_2603_20044
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle A Century of Radial Velocity and Astrometric Monitoring of 70 Oph AB: New PFS Data and Constraints on Planetary Companions
Li, Yiting
Meyer, Michael R.
D'Angiolillo, Skylar
Kane, Stephen R.
Butler, R. Paul
Shectman, Stephen A.
Mamajek, Eric E.
Teske, Johanna
Lubin, Jack
Robertson, Paul
Christiansen, Jessie L.
Isaacson, Howard
Harada, Caleb K.
Holden, Bradford
Cochran, William D.
Endl, Michael
Burt, Jennifer
Becker, Juliette
Jankowski, Alyssa
Tuthill, Peter
Clark, Catherine A.
Roettenbacher, Rachael M.
Nielsen, Eric
Bendek, Eduardo
Tokadjian, Armen
Roberson, William
Kratter, Kaitlin M.
Bergin, Edwin
Osip, Dave
Crane, Jeffrey D.
Davis, Alex
Vasisht, Gautam
Earth and Planetary Astrophysics
Solar and Stellar Astrophysics
At a distance of 5.1 pc, the 70 Oph AB binary star system is one of the most favorable targets for future direct imaging and astrometry missions surveying mature, terrestrial planets. We present new radial velocities (RVs) obtained with the Planet Finder Spectrograph (PFS) on the 6.5\,m Magellan II Clay Telescope in Chile. We collected 499 measurements of 70 Oph A and 334 measurements of 70 Oph B during 2023--2025. Combining these data with decades of archival RVs and astrometry, we derive an updated orbital solution for the binary and dynamical masses of $0.88 \pm 0.004\,M_\odot$ and $0.73 \pm 0.003\,M_\odot$ for the primary and secondary components, respectively. We find that the long-term RV variability of both components is consistent with stellar activity modulated by rotation periods, and we detect no coherent planetary signals in either component. We place upper limits on any planets orbiting in the plane of the binary. The 27 yr RV baseline for 70 Oph A excludes Jupiter-mass planets interior to 5 au and reaches a sensitivity of $0.3\,M_{\rm Jup}$ at 1 au or $0.5\,M_{\rm Jup}$ at 2 au. For 70 Oph B, with PFS data we rule out planets more massive than $0.25$--$0.3\,M_{\rm Jup}$ inside 0.5 au. We show that stable S-type orbits around 70 Oph A extend to $\sim2.5$ au, covering the habitable zone. Thus, Saturn-mass planets or smaller on stable orbits in the habitable zone of 70 Oph A are allowed. Overall, our results provide important guidance for future planet searches around this stellar system.
title A Century of Radial Velocity and Astrometric Monitoring of 70 Oph AB: New PFS Data and Constraints on Planetary Companions
topic Earth and Planetary Astrophysics
Solar and Stellar Astrophysics
url https://arxiv.org/abs/2603.20044