High surface magnetic field in red giants as a new signature of exoplanet engulfment?

High surface magnetic field in red giants as a new signature of planet engulfment?

Authors:

Privitera et al

Abstract:

Context.

Red-giant stars may engulf planets. This may increase the rotation rate of their convective envelope, which could lead to strong dynamo-triggered magnetic fields. Aims. We explore the possibility of generating magnetic fields in red giants that have gone through the process of a planet engulfment. We compare them with similar models that evolve without any planets. We discuss the impact of stellar wind magnetic braking on the evolution of the surface velocity of the parent star.

Methods.

With rotating stellar models with and without planets and an empirical relation between the Rossby number and the surface magnetic field, we deduce the evolution of the surface magnetic field along the red-giant branch. The effects of wind magnetic braking is explored using a relation deduced from MHD simulations.

Results.

The stellar evolution model of a 1.7 M⊙ without planet engulfment and that has a time-averaged rotation velocity during the Main-Sequence equal to 100 km s−1, shows a surface magnetic field triggered by convection larger than 10 G only at the base of the red giant branch, that means for gravities log g>3. When a planet engulfment occurs, such magnetic field can also appear at much lower gravities, i.e. at much higher luminosities along the red giant branch. Typically the engulfment of a 15 MJ planet produces a dynamo triggered magnetic field larger than 10 G for gravities between 2.5 and 1.9. We show that for reasonable wind magnetic braking laws, the high surface velocity reached after a planet engulfment may be maintained sufficiently long for being observable.

Conclusions.

High surface magnetic fields for red giants in the upper part of the red giant branch is a strong indication of a planet engulfment or of an interaction with a companion. Our theory can be tested by observing fast rotating red giants and check whether they show magnetic fields.

HAT-P-65b and HAT-P-66b: Two Transiting Inflated Hot Jupiters and Observational Evidence for the Re-Inflation of Close-In Giant Planets

HAT-P-65b and HAT-P-66b: Two Transiting Inflated Hot Jupiters and Observational Evidence for the Re-Inflation of Close-In Giant Planets

Authors:

Hartman et al

Abstract:

We present the discovery of the transiting exoplanets HAT-P-65b and HAT-P-66b, with orbital periods of 2.6055 d and 2.9721 d, masses of 0.527±0.083 MJ and 0.783±0.057 MJ and inflated radii of 1.89±0.13 RJ and 1.59+0.16−0.10 RJ, respectively. They orbit moderately bright (V=13.145±0.029, and V=12.993±0.052) stars of mass 1.212±0.050 M⊙ and 1.255+0.107−0.054 M⊙. The stars are at the main sequence turnoff. While it is well known that the radii of close-in giant planets are correlated with their equilibrium temperatures, whether or not the radii of planets increase in time as their hosts evolve and become more luminous is an open question. Looking at the broader sample of well-characterized close-in transiting giant planets, we find that there is a statistically significant correlation between planetary radii and the fractional ages of their host stars, with a false alarm probability of only 0.0041%. We find that the correlation between the radii of planets and the fractional ages of their hosts is fully explained by the known correlation between planetary radii and their present day equilibrium temperatures, however if the zero-age main sequence equilibrium temperature is used in place of the present day equilibrium temperature then a correlation with age must also be included to explain the planetary radii. This suggests that, after contracting during the pre-main-sequence, close-in giant planets are re-inflated over time due to the increasing level of irradiation received from their host stars. Prior theoretical work indicates that such a dynamic response to irradiation requires a significant fraction of the incident energy to be deposited deep within the planetary interiors.

HD 175370b: A Gas Giant in a 349.5 day Orbit Around an K Giant Star

The discovery of a planetary candidate around the evolved low-mass Kepler giant star HD 175370

Authors:

Hrudková et al

Abstract:

We report on the discovery of a planetary companion candidate with a minimum mass Msini = 4.6 M_J orbiting the K2 III giant star HD 175370 (KIC 007940959). This star was a target in our program to search for planets around a sample of 95 giant stars observed with Kepler. This detection was made possible using precise stellar radial velocity measurements of HD 175370 taken over five years and four months using the coude echelle spectrograph of the 2-m Alfred Jensch Telescope and the fibre-fed echelle spectrograph HERMES of the 1.2-m Mercator Telescope. Our radial velocity measurements reveal a periodic (349.5 days) variation with a semi-amplitude K = 133 m/s, superimposed on a long-term trend. A low-mass stellar companion with an orbital period of ~88 years in a highly eccentric orbit and a planet in a Keplerian orbit with an eccentricity e = 0.22 are the most plausible explanation of the radial velocity variations. However, we cannot exclude the existence of stellar envelope pulsations as a cause for the low-amplitude radial velocity variations and only future continued monitoring of this system may answer this uncertainty. From Kepler photometry we find that HD 175370 is most likely a low-mass red-giant branch or asymptotic-giant branch star.

EPIC 211351816.01: A (Re-?)Inflated Planet Orbiting a Red Giant Star

EPIC 211351816.01: A (Re-?)Inflated Planet Orbiting a Red Giant Star

Authors:

Grunblatt et al

Abstract:

Giant planets with high incident fluxes have been observed with radii larger than thermal evolution models would allow. Although these inflated planets have been known for almost two decades, it is unclear whether their inflation is caused by deposition of energy from the host star, or inhibited cooling of the planet. These processes can be distinguished if the planet becomes highly irradiated only when the host star evolves onto the red giant branch. We report the discovery of EPIC 211351816.01, a 1.27 +/- 0.09 RJ, 1.10 +/- 0.11 MJ planet orbiting a 4.20 +/- 0.14 Rsun, 1.16 +/- 0.12 Msun red giant star with an orbital period of 8.4 days. We precisely constrained stellar and planetary parameters by combining asteroseismology, spectroscopy, and granulation noise modeling along with transit and radial velocity measurements. Our calculations suggest the incident flux on this planet was ~200 +/- 100 times the flux on Earth while the star was on the main sequence, comparable to the suggested threshold flux for planet inflation. This suggests the planet was significantly less inflated in the past, and its current measured planet radius is inconsistent with delayed cooling since formation. Thus, this system provides the first clear evidence that planets are inflated directly from a process dependent on the incident stellar radiation rather than by delayed loss of heat from formation. Further studies of planets around red giant branch stars will confirm or contradict this inflation hypothesis, and may reveal a new class of re-inflated planets.

final paper with the exoplanet renamed K2-97b.

Fundamental Parameters for 164 Evolved Stars

The Pan-Pacific Planet Search V. Fundamental Parameters for 164 Evolved Stars

Authors:

Wittenmyer et al

Abstract:

We present spectroscopic stellar parameters for the complete target list of 164 evolved stars from the Pan-Pacific Planet Search, a five-year radial velocity campaign using the 3.9m Anglo-Australian Telescope. For 87 of these bright giants, our work represents the first determination of their fundamental parameters. Our results carry typical uncertainties of 100 K, 0.15 dex, and 0.1 dex in Teff, logg, and [Fe/H] and are consistent with literature values where available. The derived stellar masses have a mean of 1.31+0.28−0.25 Msun, with a tail extending to ∼2 Msun, consistent with the interpretation of these targets as "retired" A-F type stars.

HABITABLE ZONES OF POST-MAIN SEQUENCE STARS

HABITABLE ZONES OF POST-MAIN SEQUENCE STARS

Authors:

Ramirez et al

Abstract:

Once a star leaves the main sequence and becomes a red giant, its Habitable Zone (HZ) moves outward, promoting detectable habitable conditions at larger orbital distances. We use a one-dimensional radiative-convective climate and stellar evolutionary models to calculate post-MS HZ distances for a grid of stars from 3700 to 10,000 K (~M1 to A5 stellar types) for different stellar metallicities. The post-MS HZ limits are comparable to the distances of known directly imaged planets. We model the stellar as well as planetary atmospheric mass loss during the Red Giant Branch (RGB) and Asymptotic Giant Branch (AGB) phases for super-Moons to super-Earths. A planet can stay between 200 million years up to 9 Gyr in the post-MS HZ for our hottest and coldest grid stars, respectively, assuming solar metallicity. These numbers increase for increased stellar metallicity. Total atmospheric erosion only occurs for planets in close-in orbits. The post-MS HZ orbital distances are within detection capabilities of direct imaging techniques.

Close-in Planetary Systems Around Giant Stars Lack Hot Jupiters

Close-in planets around giant stars. Lack of hot-Jupiters and prevalence of multi-planetary systems

Authors:

Lillo-Box et al

Abstract:

Extrasolar planets abound in almost any possible configuration. However, until five years ago, there was a lack of planets orbiting closer than 0.5 au to giant or subgiant stars. Since then, recent detections have started to populated this regime by confirming 13 planetary systems. We discuss the properties of these systems in terms of their formation and evolution off the main sequence. Interestingly, we find that 70.0±6.6 % of the planets in this regime are inner components of multiplanetary systems. This value is 4.2σ higher than for main-sequence hosts, which we find to be 42.4±0.1 %. The properties of the known planets seem to indicate that the closest-in planets (a less than 0.06 au) to main-sequence stars are massive (i.e., hot Jupiters) and isolated and that they are subsequently engulfed by their host as it evolves to the red giant branch, leaving only the predominant population of multiplanetary systems in orbits 0.06 less than a less than 0.5 au. We discuss the implications of this emerging observational trend in the context of formation and evolution of hot Jupiters.

TYC 3667-1280-1b: a Warm Jupiter Around a Massive Red Giant Star

TAPAS IV. TYC 3667-1280-1 b - the most massive red giant star hosting a warm Jupiter

Authors:

Niedzielski et al

Abstract:

We present the latest result of the TAPAS project that is devoted to intense monitoring of planetary candidates that are identified within the PennState-Toru\'n planet search.

We aim to detect planetary systems around evolved stars to be able to build sound statistics on the frequency and intrinsic nature of these systems, and to deliver in-depth studies of selected planetary systems with evidence of star-planet interaction processes.

The paper is based on precise radial velocity measurements: 13 epochs collected over 1920 days with the Hobby-Eberly Telescope and its High-Resolution Spectrograph, and 22 epochs of ultra-precise HARPS-N data collected over 961 days.

We present a warm-Jupiter (Teq=1350K, m2sini=5.4±0.4MJ) companion with an orbital period of 26.468 days in a circular (e=0.036) orbit around a giant evolved (logg=3.11±0.09, R=6.26±0.86R⊙) star with M⋆=1.87±0.17M⊙. This is the most massive and oldest star found to be hosting a close-in giant planet. Its proximity to its host (a=0.21au) means that the planet has a 13.9±2.0% probability of transits; this calls for photometric follow-up study.

This massive warm Jupiter with a near circular orbit around an evolved massive star can help set constraints on general migration mechanisms for warm Jupiters and, given its high equilibrium temperature, can help test energy deposition models in hot Jupiters.

High Metalicity Stars Preferentially Form Gas Giants

Four new planets around giant stars and the mass-metallicity correlation of planet-hosting stars

Authors:

Jones et al

Abstract:

CONTEXT.

Exoplanet searches have demonstrated that giant planets are preferentially found around metal-rich stars and that their fraction increases with the stellar mass. AIMS. During the past six years, we have conducted a radial velocity follow-up program of 166 giant stars, to detect substellar companions, and characterizing their orbital properties. Using this information, we aim to study the role of the stellar evolution in the orbital parameters of the companions, and to unveil possible correlations between the stellar properties and the occurrence rate of giant planets.

METHODS.

Using FEROS and CHIRON spectra, we have computed precision radial velocities and we have derived atmospheric and physical parameters for all of our targets. Additionally, velocities computed from UCLES spectra are presented here. By studying the periodic radial velocity signals, we have detected the presence of several substellar companions.

RESULTS.

We present four new planetary systems around the giant stars HIP8541, HIP74890, HIP84056 and HIP95124. Additionally, we find that giant planets are more frequent around metal-rich stars, reaching a peak in the detection of f = 16.7+15.5−5.9% around stars with [Fe/H] ∼ 0.35 dex. Similarly, we observe a positive correlation of the planet occurrence rate with the stellar mass, between M⋆ ∼ 1.0 -2.1 M⊙, with a maximum of f = 13.0+10.1−4.2%, at M⋆ = 2.1 M⊙.

CONCLUSIONS.

We conclude that giant planets are preferentially formed around metal-rich stars. Also, we conclude that they are more efficiently formed around more massive stars, in the mass range of M⋆ ∼ 1.0 - 2.1 M⊙. These observational results confirm previous findings for solar-type and post-MS hosting stars, and provide further support to the core-accretion formation model.

Did Lithium Rich Giant Stars eat Their hot Jupiters?

The Gaia-ESO Survey: A simple explanation for the Li-rich giant problem

Authors:

Casey et al

Abstract:

The discovery of lithium-rich giants contradicts expectations from canonical stellar evolution. Although multiple scenarios have been proposed to preserve or produce Li, no model can explain the ensemble properties of Li-rich giants. We report on the serendipitous discovery of 20 Li-rich giants observed through the Gaia-ESO Survey. Our sample is one of the largest in the literature, and includes nine towards the CoRoT fields. We explore all mechanisms proposed to explain Li-rich giants. While the planet accretion scenario was presented to reconcile observations of Li-rich giants across the RGB/AGB, this is inconsistent with recent studies of close-in giant planets. We highlight recent observations of the difference in hot Jupiter occurrence rates around dwarf and sub-giant stars as evidence for their tidal destruction when the convective envelope expands. Therefore any close-in giant planet is likely to be engulfed well before the host evolves up the RGB/AGB. When this occurs, simulations indicate a giant planet will provide a small reservoir of unburnt Li to replenish the stellar photospheric abundance, and subsequently induce deep mixing to produce additional Li. We argue these two independent lines of evidence actually predict the existence of Li-rich giants, and suggests they should be preferentially found before the luminosity bump at near-solar metallicities, consistent with observations. This scenario explains (indeed, predicts) the majority properties of Li-rich giants, leaving a minority population of evolved metal-poor Li-rich giants which are explainable by internal mixing processes associated with late evolutionary stages, or mass transfer from more evolved AGB stars.

Hunting for Exoplanets in the Habitable Zones of Evolved Stars

All throughout the universe, there are stars in varying phases and ages. The oldest detected Kepler planets (exoplanets found using NASA's Kepler telescope) are about 11 billion years old, and the planetary diversity suggests that around other stars, such initially frozen worlds could be the size of Earth and could even provide habitable conditions once the star becomes older. Astronomers usually looked at middle-aged stars like our sun, but to find habitable worlds, one needs to look around stars of all ages.

In their work, Ramses M. Ramirez, research associate at Cornell's Carl Sagan Institute and Lisa Kaltenegger, associate professor of astronomy and director of the Carl Sagan Institute, have modeled the locations of the habitable zones for aging stars and how long planets can stay in it. Their research, "Habitable Zones of Post-Main Sequence Stars," is published in the Astrophysical Journal May 16.

The "habitable zone" is the region around a star in which water on a planet's surface is liquid and signs of life can be remotely detected by telescopes.

link.

Simulating the Interactions of a Giant Host Star and a 10 Jupiter Mass Exoplanet

Hydrodynamic Simulations of the Interaction between Giant Stars and Planets

Authors:

Staff et al

Abstract:

We present the results of hydrodynamic simulations of the interaction between a 10 Jupiter mass planet and a red or asymptotic giant branch stars, both with a zero-age main sequence mass of 3.5 M⊙. Dynamic in-spiral timescales are of the order of few years and a few decades for the red and asymptotic giant branch stars, respectively. The planets will eventually be destroyed at a separation from the core of the giants smaller than the resolution of our simulations, either through evaporation or tidal disruption. As the planets in-spiral, the giant stars' envelopes are somewhat puffed up. Based on relatively long timescales and even considering the fact that further in-spiral should take place before the planets are destroyed, we predict that the merger would be difficult to observe, with only a relatively small, slow brightening. Very little mass is unbound in the process. These conclusions may change if the planet's orbit enhances the star's main pulsation modes. Based on the angular momentum transfer, we also suspect that this star-planet interaction may be unable to lead to large scale outflows via the rotation-mediated dynamo effect of Nordhaus and Blackman. Detectable pollution from the destroyed planets would only result for the lightest, lowest metallicity stars. We furthermore find that in both simulations the planets move through the outer stellar envelopes at Mach-3 to Mach-5, reaching Mach-1 towards the end of the simulations. The gravitational drag force decreases and the in-spiral slows down at the sonic transition, as predicted analytically.

Evolved stars and the origin of abundance trends in planet hosts

Evolved stars and the origin of abundance trends in planet hosts

Authors:

Maldonado et al

Abstract:

Tentative evidence that the properties of evolved stars with planets may be different from what we know for MS hosts has been recently reported. We aim to test whether evolved stars with planets show any chemical peculiarity that could be related to the planet formation process. We determine in a consistent way the metallicity and individual abundances of a large sample of evolved (subgiants and red giants) and MS stars with and without known planetary companions. No differences in the [X/Fe] vs. condensation temperature (Tc) slopes are found between the samples of planet and non-planet hosts when all elements are considered. However, if the analysis is restricted to only refractory elements, differences in the Tc-slopes between stars with and without known planets are found. This result is found to be dependent on the stellar evolutionary stage, as it holds for MS and subgiant stars, while there seem to be no difference between planet and non-planet hosts among the sample of giants. A search for correlations between the Tc-slope and the stellar properties reveals significant correlations with the stellar mass and the stellar age. The data also suggest that differences in terms of mass and age between MS planet and non-planet hosts may be present. Our results are well explained by radial mixing in the Galaxy. The sample of giant contains stars more massive and younger than their MS counterparts. This leads to a sample of stars possibly less contaminated by stars not born in the solar neighbourhood, leading to no chemical differences between planet and non planet hosts. The sample of MS stars may contain more stars from the outer disc (specially the non-planet host sample) which might led to the differences observed in the chemical trends.

HD 5583 and BD+15 2375: Two Evolved Giant Stars With Warm Jupiters

Tracking Advanced Planetary Systems (TAPAS) with HARPS-N. III. HD 5583 and BD+15 2375 - two cool giants with warm companions

Authors:

Niedzielski et al

Abstract:

Evolved stars are crucial pieces to understand the dependency of the planet formation mechanism on the stellar mass and to explore deeper the mechanism involved in star-planet interactions. Over the past ten years, we have monitored about 1000 evolved stars for radial velocity variations in search for low-mass companions under the Penn State - Torun Centre for Astronomy Planet Search program with the Hobby-Eberly Telescope. Selected prospective candidates that required higher RV precision measurements have been followed with HARPS-N at the 3.6 m Telescopio Nazionale Galileo under the TAPAS project.

We aim to detect planetary systems around evolved stars to be able to build sound statistics on the frequency and intrinsic nature of these systems, and to deliver in-depth studies of selected planetary systems with evidence of star-planet interaction processes. For HD 5583 we obtained 14 epochs of precise RV measurements collected over 2313 days with the Hobby-Eberly Telescope (HET), and 22 epochs of ultra-precise HARPS-N data collected over 976 days. For BD+15 2375 we collected 24 epochs of HET data over 3286 days and 25 epochs of HARPS-S data over 902 days.

We report the discovery of two planetary mass objects orbiting two evolved Red Giant stars: HD~5583 has a m sin i = 5.78 MJ companion at 0.529~AU in a nearly circular orbit (e=0.076), the closest companion to a giant star detected with the RV technique, and BD+15~2735 that with a m sin i= 1.06 MJ holds the record of the lightest planet found so far orbiting an evolved star (in a circular e=0.001, 0.576~AU orbit). These are the third and fourth planets found within the TAPAS project, a HARPS-N monitoring of evolved planetary systems identified with the Hobby-Eberly Telescope.

The Evolution of Exoplanet Systems After Their Host Star Leaves to Main Sequence

Post-main-sequence planetary system evolution

Author:

Veras

Abstract:

The fates of planetary systems provide unassailable insights into their formation and represent rich cross-disciplinary dynamical laboratories. Mounting observations of post-main-sequence planetary systems necessitate a complementary level of theoretical scrutiny. Here, I review the diverse dynamical processes which affect planets, asteroids, comets and pebbles as their parent stars evolve into giant branch, white dwarf and neutron stars. This reference provides a foundation for the interpretation and modelling of currently known systems and upcoming discoveries.

Radio Emission from Red-Giant Hot Jupiters

Radio Emission from Red-Giant Hot Jupiters

Authors:

Fuji et al

Abstract:

When planet-hosting stars evolve off the main sequence and go through the red-giant branch, the stars become orders of magnitudes more luminous and at the same time lose mass at much higher rates than their main-sequence counterparts. Accordingly, planetary companions around them at orbital distances of a few AU, if they exist, will be heated up to the level of canonical hot Jupiters and also subjected to a dense stellar wind. Given that magnetized planets interacting with stellar winds emit radio waves, such "Red-Giant Hot Jupiters" (RGHJs) may also be candidate radio emitters. We estimate the spectral auroral radio intensity of RGHJs based on the empirical relation with the stellar wind as well as a proposed scaling for planetary magnetic fields. RGHJs might be intrinsically as bright as or brighter than canonical hot Jupiters, and about 100 times brighter than equivalent objects around main-sequence stars. We examine the capabilities of low-frequency radio observatories to detect this emission and find that the signal from a RGHJ may be detectable at distances up to a few hundred parsecs with the Square Kilometer Array.

Sharpest View Ever of Dusty Disk Around Evolved Host Star IRAS 08544-4431

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Gas Giants HD 47366b & HD 47366c Have Potentially Weird Orbits Around Their K Giant Star

A Pair of Giant Planets around the Evolved Intermediate-Mass Star HD 47366: Multiple Circular Orbits or a Mutually Retrograde Configuration

Authors:

Sato et al

Abstract:

We report the detection of a double planetary system around the evolved intermediate-mass star HD 47366 from precise radial-velocity measurements at Okayama Astrophysical Observatory, Xinglong Station, and Australian Astronomical Observatory. The star is a K1 giant with a mass of 1.81+-0.13M_sun, a radius of 7.30+-0.33R_sun, and solar metallicity. The planetary system is composed of two giant planets with minimum mass of 1.75^{+0.20}_{-0.17}Mjup and 1.86^{+0.16}_{-0.15}Mjup, orbital period of 363.3^{+2.5}_{-2.4} d and 684.7^{+5.0}_{-4.9} d, and eccentricity of 0.089^{+0.079}_{-0.060} and 0.278^{+0.067}_{-0.094}, respectively, which are derived by a double Keplerian orbital fit to the radial-velocity data. The system adds to the population of multi-giant-planet systems with relatively small orbital separations, which are preferentially found around evolved intermediate-mass stars. Dynamical stability analysis for the system revealed, however, that the best-fit orbits are unstable in the case of a prograde configuration. The system could be stable if the planets were in 2:1 mean-motion resonance, but this is less likely considering the observed period ratio and eccentricity. A present possible scenario for the system is that both of the planets have nearly circular orbits, namely the eccentricity of the outer planet is less than ~0.15, which is just within 1.4sigma of the best-fit value, or the planets are in a mutually retrograde configuration with a mutual orbital inclination larger than 160 degree.

8 Giant Stars Discovered to Have Exoplanets

Precise radial velocities of giant stars VIII. Testing for the presence of planets with CRIRES Infrared Radial Velocities

Authors:

Trifonov et al

Abstract:

We have been monitoring 373 very bright (V less than 6 mag) G and K giants with high precision optical Doppler spectroscopy for more than a decade at Lick Observatory. Our goal was to discover planetary companions around those stars and to better understand planet formation and evolution around intermediate-mass stars. However, in principle, long-term, g-mode nonradial stellar pulsations or rotating stellar features, such as spots, could effectively mimic a planetary signal in the radial velocity data. Our goal is to compare optical and infrared radial velocities for those stars with periodic radial velocity patterns and to test for consistency of their fitted radial velocity semiamplitudes. Thereby, we distinguish processes intrinsic to the star from orbiting companions as reason for the radial velocity periodicity observed in the optical. Stellar spectra with high spectral resolution have been taken in the H-band with the CRIRES near-infrared spectrograph at ESO's VLT for 20 stars of our Lick survey. Radial velocities are derived using many deep and stable telluric CO2 lines for precise wavelength calibration. We find that the optical and near-infrared radial velocities of the giant stars in our sample are consistent. We present detailed results for eight stars in our sample previously reported to have planets or brown dwarf companions. All eight stars passed the infrared test. We conclude that the planet hypothesis provides the best explanation for the periodic radial velocity patterns observed for these giant stars.

Observing the Circumstellar Disks of B[e] Supergiants in the Magellanic Clouds

Disk tracing for B[e] supergiants in the Magellanic Clouds

Authors:

Maravelias et al

Abstract:

B[e] supergiants are evolved massive stars with a complex circumstellar environment. A number of important emission features probe the structure and the kinematics of the circumstellar material. In our survey of Magellanic Cloud B[e] supergiants we focus on the [OI] and [CaII] emission lines, which we identified in four more objects.