Detection and Bulk Properties of the HR 8799 Planets with High-resolution Spectroscopy

Wang, Jason; Ruffio, Jean-Baptiste; Morris, Evan; Delorme, Jacques Robert; Jovanović, Nemanja; Pezzato, Jacklyn; Echeverri, Daniel; Finnerty, Luke; Hood, Callie E.; Zanazzi, J. J.; Bryan, M.; Bond, C.; Cetre, Sylvain; Martin, Emily C.; Mawet, Dimitri; Skemer, Andrew J.; Baker, Ashley; Xuan, Jerry W.; Wallace, J. Kent; Wang, Ji; Bartos, Randall; Blake, Geoffrey A.; Boden, A. F.; Buzard, Cam; Calvin, Benjamin; Chun, Mark; Doppmann, Greg; Dupuy, Trent J.; Duchêne, Gaspard; Feng, Y. Katherina; Fitzgerald, Michael P.; Fortney, Jonathan J.; Freedman, Richard; Knutson, Heather A.; Konopacky, Quinn; Lilley, Scott; Liu, Mengmeng; López, Ronald; Lupu, Roxana; Marley, Mark S.; Meshkat, Tiffany; Miles, Brittany; Millar‐Blanchaer, Maxwell A.; Ragland, Sam; Roy, Arpita; Ruane, Garreth; Sappey, Ben; Schofield, Tobias; Weiss, Lauren M.; Wetherell, Edward; Wizinowich, Peter; Ygouf, Marie

doi:10.3847/1538-3881/ac1349

Cited by 65 publications

(54 citation statements)

References 127 publications

(222 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An important step toward understanding the origins of the coldest directly imaged planets like 51 Eri b will include spectroscopic measurements to probe its composition with existing (e.g., Keck/KPIC; Mawet et al 2017;Wang et al 2021b) and upcoming ground-based facilities (e.g., Subaru/REACH; Kotani et al 2020;and VLT/HiRISE;Vigan et al 2018), as well as JWST. On a similar time horizon, we expect to see some improvement in the measured mass of 51 Eri b with future Gaia data releases.…”

Section: Discussionmentioning

confidence: 99%

Limits on the mass and initial entropy of 51 Eri b from Gaia EDR3 astrometry

Dupuy

Brandt

2021

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

51 Eri b is one of the only young planets consistent with a wide range of possible initial entropy states, including the cold-start scenario associated with some models of planet formation by core accretion. The most direct way to constrain the initial entropy of a planet is by measuring its luminosity and mass at a sufficiently young age that the initial conditions still matter. We present the tightest upper limit on 51 Eri b’s mass yet (M < 11 MJup at 2σ) using a cross-calibration of Hipparcos and Gaia EDR3 astrometry and the orbit-fitting code orvara. We also reassess its luminosity using a direct, photometric approach, finding $\log (\rm{L_{\rm bol}}/\rm{\mathrm{L}_{\odot }}) = -5.5\pm 0.2$ dex. Combining this luminosity with the 24 ± 3 Myr age of the β Pic moving group, of which 51 Eri is a member, we derive mass distributions from a grid of evolutionary models that spans a wide range of initial entropies. We find that 51 Eri b is inconsistent with the coldest-start scenarios, requiring an initial entropy of >8 kB baryon−1 at 97 per cent confidence. This result represents the first observational constraint on the initial entropy of a potentially cold-start planet, and it continues the trend of dynamical masses for directly imaged planets pointing to warm- or hot-start formation scenarios.

show abstract

Section: Discussionmentioning

confidence: 99%

Limits on the mass and initial entropy of 51 Eri b from Gaia EDR3 astrometry

Dupuy

Brandt

2021

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

show abstract

“…With a median rotation period of ∼ 12 hr for young free-floating and companion objects, this work highlights the importance of long duration observations in order to measure a full period. For ground-based observations with the E-ELT, TMT and/or GMT multiple nights of observations may be necessary to capture the periodicity, however the fastest rotators could be prioritized by measuring v sin(i) values prior to variability searches (Wang et al 2021). Finally, ongoing variability surveys of Y dwarfs will be critical in revealing the potential for detecting variability in the coldest exoplanets (Cushing, M. C. et al, in preparation).…”

Section: Lessons For Variability Monitoring Of Directly-imaged Exopla...mentioning

confidence: 99%

Let the Great World Spin: Revealing the Stormy, Turbulent Nature of Young Giant Exoplanet Analogs with the Spitzer Space Telescope

Vos,

Faherty,

Gagné

et al. 2022

Preprint

View full text Add to dashboard Cite

We present a survey for photometric variability in young, low-mass brown dwarfs with the Spitzer Space Telescope. The 23 objects in our sample show robust signatures of youth and share properties with directly-imaged exoplanets. We present three new young objects: 2MASS J03492367+0635078, 2MASS J09512690 −8023553 and 2MASS J07180871−6415310. We detect variability in 13 young objects, and find that young brown dwarfs are highly likely to display variability across the L2-T4 spectral type range. In contrast, the field dwarf variability occurrence rate drops for spectral types >L9. We examine the variability amplitudes of young objects and find an enhancement in maximum amplitudes compared to field dwarfs. We speculate that the observed range of amplitudes within a spectral type may be influenced by secondary effects such as viewing inclination and/or rotation period. We combine our new rotation periods with the literature to investigate the effects of mass on angular momentum evolution. While high mass brown dwarfs (> 30M Jup ) spin up over time, the same trend is not apparent for lower mass objects (< 30M Jup ), likely due to the small number of measured periods for old, low-mass objects. The rotation periods of companion brown dwarfs and planetary-mass objects are consistent with those of isolated objects with similar ages and masses, suggesting similar angular momentum histories. Within the AB Doradus group, we find a high variability occurrence rate and evidence for common angular momentum evolution. The results are encouraging for future variability searches in directly-imaged exoplanets with facilities such as the James Webb Space Telescope and 30-meter telescopes.

show abstract

“…The atmospheres of directly imaged planets are generally similar to higher mass brown dwarfs of the same effective temperature (e.g., Chilcote et al 2017).Planets of the L and T spectral type have redder spectra in the near-infrared than the higher-mass brown dwarfs, which could be due to having thicker clouds (e.g., De Rosa et al 2016). For the four super-Jupiters orbiting HR 8799 (Marois et al 2008(Marois et al , 2010, we have accumulated a diverse set of photometry and spectra that point to a complex cloud model (Bowler et al 2010; Barman et al 2011;Konopacky et al 2013;Currie et al 2014;Ingraham et al 2014;Skemer et al 2014;Zurlo et al 2016;Bonnefoy et al 2016;Greenbaum et al 2018;Mollière et al 2020;Ruffio et al 2021;Wang et al 2020Wang et al , 2021. In particular, the temperature of the four planets lie around the transition between the L and T spectral types, where partly cloudy atmospheres are thought to induce the enhanced photometric variability (> 2% in J band) we see in free-floating substellar objects at this temperature range (Radigan et al 2014).…”

Section: Introductionmentioning

confidence: 99%

Atmospheric Monitoring and Precise Spectroscopy of the HR 8799 Planets with SCExAO/CHARIS*

Wang

Chilcote

Lozi³

et al. 2022

Self Cite

View full text Add to dashboard Cite

The atmospheres of gas giant planets are thought to be inhomogeneous due to weather and patchy clouds. We present two full nights of coronagraphic observations of the HR 8799 planets using the CHARIS integral field spectrograph behind the SCExAO adaptive optics system on the Subaru Telescope to search for spectrophomometric variability. We did not detect significant variability signals, but placed the lowest variability upper limits for HR 8799c and d. Based on injection-recovery tests, we expected to have a 50% chance to detect signals down to 10% H-band photometric variability for HR 8799c and down to 30% H-band variability for HR 8799d. We also investigated spectral variability and expected a 50% chance to recover 20% variability in the H/K flux ratio for HR 8799c. We combined all the data from the two nights to obtain some of the most precise spectra obtained for HR 8799c, d, and e. Using a grid of cloudy radiative–convective–thermochemical equilibrium models, we found all three planets prefer supersolar metallicity with effective temperatures of ∼1100 K. However, our high signal-to-noise spectra show that HR 8799d has a distinct spectrum from HR 8799c, possibly preferring more vertically extended and uniform clouds and indicating that the planets are not identical.

show abstract

Detection and Bulk Properties of the HR 8799 Planets with High-resolution Spectroscopy

Cited by 65 publications

References 127 publications

Limits on the mass and initial entropy of 51 Eri b from Gaia EDR3 astrometry

Limits on the mass and initial entropy of 51 Eri b from Gaia EDR3 astrometry

Let the Great World Spin: Revealing the Stormy, Turbulent Nature of Young Giant Exoplanet Analogs with the Spitzer Space Telescope

Atmospheric Monitoring and Precise Spectroscopy of the HR 8799 Planets with SCExAO/CHARIS*

Contact Info

Product

Resources

About