Direct imaging and astrometric detection of a gas giant planet orbiting an accelerating star

Creators: Currie, Thayne; Brandt, G. Mirek; Brandt, Timothy D.; Lacy, Brianna; Burrows, Adam; Guyon, Olivier; Tamura, Motohide; Liu, Ranger Y.; Sagynbayeva, Sabina; Tobin, Taylor; Chilcote, Jeffrey; Groff, Tyler D.; Marois, Christian; Thompson, William; Murphy, Simon J.; Kuzuhara, Masayuki; Lawson, Kellen; Lozi, Julien; Deo, Vincent; Vievard, Sébastien; Skaf, Nour; Uyama, Taichi; Jovanovic, Nemanja; Martinache, Frantz; Kasdin, N. Jeremy; Kudo, Tomoyuki; McElwain, Michael W.; Janson, Markus; Wisniewski, John P.; Hodapp, Klaus; Nishikawa, Jun; Hełminiak, Krzysztof; Kwon, Jungmi; Hayashi, Masahiko

Abstract

Direct imaging of gas giant exoplanets provides information on their atmospheres and the architectures of planetary systems. However, few planets have been detected in blind surveys with direct imaging. Using astrometry from the Gaia and Hipparcos spacecraft, we identified dynamical evidence for a gas giant planet around the nearby star HIP 99770. We confirmed the detection of this planet with direct imaging using the Subaru Coronagraphic Extreme Adaptive Optics instrument. The planet, HIP 99770 b, orbits 17 astronomical units from its host star, receiving an amount of light similar to that reaching Jupiter. Its dynamical mass is 13.9 to 16.1 Jupiter masses. The planet-to-star mass ratio [(7 to 8) × 10⁻³] is similar to that of other directly imaged planets. The planet's atmospheric spectrum indicates an older, less cloudy analog of the previously imaged exoplanets around HR 8799.

Additional Information

© 2023 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. This is an article distributed under the terms of the Science Journals Default License. We thank the three anonymous referees for their helpful comments and suggestions, which improved the quality of this paper. We thank the Subaru Time Allocation committee, NASA-Keck Time Allocation Committee, and recent Subaru Director Michitoshi Yoshida for their support of this program through Open Use and Director's Discretionary Time allocations. This research is based on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan. The authors acknowledge the very important cultural role and reverence that the summit of Maunakea holds within the Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. We thank J. Gagne, E. Mamajek, R. Gray, and J. Jones for extensive and helpful conversations regarding HIP 99770's properties. This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. The development of SCExAO was supported by the Japan Society for the Promotion of Science (Grant-in-Aid for Research 23340051, 26220704, 23103002, 19H00703, and 19H00695), the Astrobiology Center of the National Institutes of Natural Sciences, Japan, the Mt Cuba Foundation, and the director's contingency fund at Subaru Telescope. T.C. was funded under NASA–XRP program NNX17AF88G and NASA-Keck Principal Investigator Award (Program 2020A_N027). B.L. is supported by a 51 Pegasi Postdoctoral Fellowship. C.M. acknowledges the support of the Natural Sciences and Engineering Research Council of Canada (NSERC). S.J.M. was supported by the Australian Research Council (ARC) through Future Fellowship FT210100485. V.D. acknowledges support from NASA grant 80NSSC19K0336 and Heising-Simons Foundation grant no. 2020-1823. M.T. is supported by JSPS KAKENHI grant 18H05442. Author contributions: T.C. proposed and conducted the observations, reduced data, and led writing of the paper. G.M.B. and T.D.B. assisted with target selection and performed the joint direct imaging and astrometry analysis. B.L. and A.B. generated planet atmosphere models. R.Y.L. and S.S. performed separate data reductions; T.T. contributed to data reduction. O.G., J.L., V.D., S.V., N.S., J.C., T.G., and T.K. operated Subaru's facility AO system, SCExAO, and CHARIS during observations. C.M. and W.T. reduced and analyzed archival Gemini data. S.J.M. performed astroseismology analysis. M.K., T.U., M.M., M.J., J.W., K.H., J.N., K.H., and J.K. contributed to proposals and draft comments. N.J., F.M., N.J.K., and M.H. developed, commissioned, and maintained SCExAO and CHARIS and contributed to paper comments. M.T. oversaw group collaboration, proposals, and draft circulation. Data and materials availability: The raw CHARIS data are available from the Subaru SMOKA archive at https://smoka.nao.ac.jp/. The Keck data are available from the Keck Observatory Archive at https://koa.ipac.caltech.edu/cgi-bin/KOA/nph-KOAlogin. The archival data we used from the WISE mission, Spitzer Space Telescope, and Herschel Space Observatory are available from the NASA/IPAC Infrared Science Archive https://irsa.ipac.caltech.edu/applications/Gator/; the Spitzer data we used are from the Spitzer Enhanced Imaging Products data set. The Gemini data are available from the Gemini Observatory archive at https://archive.gemini.edu/searchform. The TESS data are available from the Mikulski Archive for Space Telescopes at https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html. In all cases, data can be found by searching for "HIP 99770" or "HIP99770." The measured spectrum of HIP 99770 b is available as data S1. The Lacy/Burrows atmospheric models that we used to interpret the spectrum are available as data S2. The derived properties of the host star and the planet are listed in tables S1 and S4, respectively. The measured relative astrometric is reported in table S3. The authors declare no competing interests.

Additional details

Views

Downloads

	All versions	This version
Views	0	0
Downloads	0	0
Data volume	0 Bytes	0 Bytes

More info on how stats are collected....

Resource type: Journal Article
Publisher: American Association for the Advancement of Science
Published in: Science, 380(6641), 198-203, ISSN: 0036-8075.