Application Form for (Subaru Keck) Telescope Time

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1 (Page 1) Subaru Telescope National Astronomical Observatory of Japan Semester S10B Received 03/12/2010 Application Form for (Subaru Keck) Telescope Time 1. Title of Proposal Search for Outer Massive Bodies around Special Transiting Planetary Systems 2. Principal Investigator Name: Narita Norio Institute: Mailing Address: Address: National Astronomical Observatory of Japan Osawa, Mitaka, Tokyo , Japan Phone: Fax: Scientific Category Solar System Normal Stars Extrasolar Planets Star and Planet Formation Compact Objects and SNe Milky Way Local Group ISM Nearby Galaxies AGN and QSO Activity QSO Abs. Lines and IGM Clusters of Galaxies Large-Scale Structure Gravitational Lenses High-z Galaxies Cosmological Parameters Miscellaneous 4. Abstract (approximately 200 words) Recent progress in observations of extrasolar planets have dramatically pushed our understanding of orbital evolutions of planetary systems. In particular, eccentric planets or highly tilted planets (namely, the planetary orbital axis is tilted relative to the stellar spin axis) in transiting planetary systems are very important targets to test planetary migration theories by observations. Since eccentric planets and highly tilted planets should have outer massive bodies (giant planets, brown dwarfs, or binary stars) based on planetary migration theories, these special targets are very promising to find massive bodies in outer region. To detect or constrain such outer massive bodies, we propose 1 night direct imaging observation for 5 special transiting planetary systems with the Keck/NIRC2. Combined with theoretical calculations of Kozai migration models, detections of any massive bodies or even no detection of a stellar companion (certainly achievable) will provide us conclusive information to discriminate migration mechanisms of the target planets. 5. Co-Investigators Name Institute Name Institute Ryo Kandori NAOJ Bun ei Sato Tokyo Institute of Technology Tomoyuki Kudo NAOJ Ryuji Suzuki Subaru Telescope Masayuki Kuzuhara NAOJ Yasuhiro Takahashi NAOJ Motohide Tamura NAOJ 6. List of Applicants Related Publications (last 5 years) 1. Narita, N., et al. 2010, PASJ in press 2. Narita, N., et al. 2009b, PASJ Letters, vol. 61, L35-L40 3. Narita, N., et al. 2009a, PASJ, vol. 61, Narita, N., et al. 2008, PASJ Letters, vol. 60, L1-L5 5. Narita, N., et al. 2007, PASJ, vol. 59, Narita, N., et al. 2005, PASJ, vol. 57, Tamura, M., et al. 2006, SPIE, vol Sato, B., et al ApJ, vol. 703, Sato, B., et al PASJ, vol. 60, Sato, B., et al PASJ, vol. 60, Sato, B., et al ApJ, vol. 661, Sato, B., et al ApJ, vol. 633,

2 (Page 2) Pages 2 and 3 will be used for technical review by observatory staff. Please provide here clear and detailed information for these purposes. The entire proposal including scientific justification will be passed to support astronomers for preparation of observations upon acceptance. 7. Title of Proposal Search for Outer Massive Bodies around Special Transiting Planetary Systems 8. Observing Run Instrument # Nights Moon Preferred Dates Acceptable Dates Observing Modes NIRC2/NGS-AO 1 Gray Jan middle-late Jan H band, ADI Total Requested Number of Nights 1 Minimum Acceptable Number of Nights 1 9. List of Targets (Use an additional sheet if this space is not sufficient) Target Name RA Dec Equinox Magnitude (Band) XO J H = 8.85 CoRoT J H = HAT-P J H = GJ J H = WASP J H = Scheduling Requirements Late January (January 25-30) is most favorable since we will be able to observe all the targets for a few hours with sufficient field rotation angles, which are critically important for the angular differential imaging technique (ADI). Middle-late January is still acceptable, but we may not be able to observe WASP-14 with a sufficient field rotation angle. In bright lunar phase, one or two of our targets may be severely affected by the Moon, since the separation angle is less than 30 degrees. Thus near full moon phase is inconvenient for our observation. 11. Instrument Requirements Request Remote Observation 12. Experience Our team has extensive experience for the data acquisition and analysis for the proposed observation based on the SEEDS project. 13. Backup Proposal in Poor Conditions (specify object names) Since our target stars are fairly bright, we will be able to conduct our observations even if the weather is poor (minimal goal will be achieved). We will also observe some standard stars for magnitude and PSF reference. In addition, if any new transiting exoplanets with significant eccentricities or spin-orbit alignment angles are discovered before the observing date, we hope to observe them in unoccupied hours.

3 (Page 3) 14. Observing Method and Technical Details Please describe in detail about instrument configuration, exposure time, required sensitivity, and so on. We aim to search for outer massive bodies (massive planets, brown dwarfs, or binary stars) around 5 transiting planetary systems. For the purpose, we will use the angular differential imaging (ADI, Marois et al. 2006) technique for the proposed observation. Since the ADI technique is most powerful if we can observe around the meridian passage of target stars, we plan to observe each target star for a few hours around its meridian passage time. We also plan to use the locally optimized combination of images algorithm (LOCI, Lafreniere et al. 2007) to maximize the efficiency of the ADI technique. We request to use the NGS-AO for our observation. The target stars are point sources and we will use our target stars themselves as guide stars. We expect that we can obtain enough Strehl ratio for all the target stars. We will use H band filter, no coronagraphic mask, and the circular rotating pupil mask for all the targets. Also, we will also use the J and K band filters to obtain multi-colar images for one of the targets. We will employ the narrow camera for XO-3, CoRoT-1, HAT-P-13, and WASP-14, and the medium camera for GJ436. Although it is of no matter even if the center region of stellar images is saturated, we limit exposure times within sec to avoid that the bright stellar halo contaminates the important outer region. As a result, we estimate that the total exposure time of the target stars would be min (corresponding contrast-ratio of from 10 5 to 10 4 ). In the beginning and the end of each target observation, we will take the PSF of each target star without saturation using a ND filter or by a short exposure. We will also observe some standard stars for reference of H band magnitude and PSF. 15. Condition of Closely-Related Past Observations Please fill in here, if this proposal is a continuation of (or inextricably related with) the previously accepted proposals. This is to describe what kind of relevant/similar proposals have existed in the past and how such previous observations were carried out. Proposal ID Title (may be abbreviated) Observational condition Achievement (%) 16. Post-Observation Status and Publications Please report the status or outcome of your main Subaru observations carried out in the past. All observations relevant to this proposal (e.g., those enumerated in the above entry 15) must be included here; otherwise, only those within last 3 years suffice. Year/Month Proposal ID PI name Status: data reduction/analysis Status: publication 2007/Jul S07A-007 Norio Narita reduced Narita et al in press 2007/Sep S07B-091 Norio Narita reduced Johnson et al /May S08A-021 Norio Narita reduced Narita et al. 2009b 2008/Nov S08B-087 Norio Narita reduced Narita et al. 2009a 2009/Jul S09A-096 Norio Narita working 2009/Jun S09A-097 Norio Narita working 2009/Nov S09B-088 Norio Narita working 2009/Nov S09B-089 Norio Narita working 17. Thesis Work This proposal is linked to the thesis preparation of 18. Subaru Open Use Intensive Programs This is a proposal for Intensive Programs.

4 Search for Outer Massive Bodies around Special Transiting Planetary Systems by Narita et al. Backgrounds and Motivation: The discoveries of over 400 extrasolar planets and the diversity of their orbital distributions dramatically changed our perception of planetary systems in the last 15 years. Especially, the existence of exoplanets in very close-in or eccentric orbits stimulated theorists to develop various models for planetary migration during planetary formation epoch. To explain the whole orbital distribution of known exoplanets, a number of planetary migration models have been proposed so far, including disk-planet interaction models (i.e., Type I and Type II migration models; e.g., Lin et al. 1996; Ida & Lin 2004), planetplanet scattering models considering gravitational interaction among multiple giant planets (i.e., jumping Jupiter models; e.g., Nagasawa et al. 2008; Chatterjee et al. 2008), or Kozai migraion models considering perturbation by a distant massive companion and coinstantaneous tidal evolution (e.g., Wu & Murray 2003; Fabrycky & Tremaine 2007). Then, how can we distinguish these planetary migration mechanisms by observations? There are 2 useful sources to discriminate migration mechanisms: the orbital eccentricity and the spin-orbit alignment angle. The orbital eccentricity of an exoplanet can be measured by radial velocity observations or secondary eclipse observations, while the spin-orbit alignment angle can be measured by observations of the Rossiter-McLaughlin effect (hereafter the RM effect: Rossiter 1924; McLaughlin 1924) for transiting planetary systems (see e.g., Ohta et al. 2005; Gaudi & Winn 2007; Hirano et al for theoretical discriptions). The information of the orbital eccentricity and the spin-orbit alignment angle is very useful to differentiate the planet-planet scattering models and the Kozai migration models from the disk-planet interaction models. It is because the planet-planet scattering models and the Kozai migration models predict a wider range of eccentricities and spin-orbit alignment angles for migrated planets, whereas the disk-planet interaction models predict that migrated planets would have only small eccentricities and spin-orbit alignment angles. Therefore, an observation of a significant eccentricity or a highly tilted orbit for a specific planet is strong evidence of a planet-planet scattering process or perturbation by an outer companion in its migration history. Indeed, very recently several transiting exoplanets reported to have significant orbital eccentricities or highly tilted orbits (e.g., Narita et al and Winn et al for HAT-P-7b). This fact leads an interesting prediction. Namely, around these eccentric or spin-orbit misaligned exoplanets, other massive bodies (e.g., massive planets, brown dwarfs, or binary stars) should exist based on the planet-planet scattering models and the Kozai migration models. In addition, since one cannot tell the planet-planet scattering models and the Kozai migration models by orbital eccentricities nor spin-orbit alignment angles alone, direct imaging of such massive bodies gives us conclusive additional information to distinguish between the two migration mechanisms of eccentric or highly tilted planets (e.g., Wu & Murray 2003 for HD80606b) Our Previous Study: Motivated by these facts, we started to search for such outer massive bodies around known transiting planetary systems with the Subaru HiCIAO (High Contrast Instrument for the Subaru next generation Adaptive Optics; Tamura et al. 2006), as part of the SEEDS project (Strategic Explorations of Exoplanets and Disks with Subaru, PI: Motohide Tamura) since 2009 November. We first targeted the transiting planetary system HAT-P-7, which was reported to have the highly tilted planet HAT-P-7b (Narita et al. 2009; Winn et al. 2009). Thus massive planets, brown dwarfs, or binary stars are expected to exist around this planetary system. Consequently, we discovered that there are 2 candidates of faint stellar companions to HAT-P-7 based on the Subaru HiCIAO observation (see figure 1). Based on the discovery, we modeled the Kozai migration for this system and constrained realizable migration mechanisms of HAT-P-7b. As a reuslt, we found that the Kozai migration scenario was realizable only in a very limited condition. We concluded that planet-planet scattering was particularly favored for HAT-P-7b, given that there is an additional giant planet in this system as is reported by Winn et al. (2009). The result will be submitted soon (Narita et al. 2010, to be submitted). By the experience for the HAT-P-7 system, we proved that high-contrast direct imaging is especially useful to discriminate planetary migration mechanisms of eccentric or highly tilted transiting planetary systems, and we established a methodology to constrain migration mechanisms of such special transiting planetary systems by combined information of the RM effect and direct imaging. We note that not only detections of planets or brown dwarfs, but also detections or even no detection of binary stars are very useful to constrain migration mechanisms of special transiting planets like HAT-P-7b. Thus we are confident that we can study other transiting planetary systems by applying the methodology and that it is a very promising scientific project. Indeed, such observational information is quite important for planetary migraion theorists to check their simulated results of orbital distributions of extrasolar planets (M. Nagasawa, private communication). In addition, no other group has started a similar direct imaging project for eccentric or highly tilted transiting planetary systems to our knowledge. Targets and Feasibility: Based on our previous experience, we have selected 5 higher priority targets for this kind of study. All of our targets have eccentric or highly tilted transiting planets, and their migration mechanisms have not yet been discriminated. The targets are sufficiently bright for our purpose (H magnitude = ). Their meridian passage times are not overlapping each other, and thus we can observe the targets for a few hours each around meridian passage times with sufficient field rotation angles, which are critically important for the angular differential imaging technique (ADI, Marois et al. 2006). We also plan to use the locally optimized combination of images algorithm (LOCI, Lafreniere et al. 2007) to maximize the efficiency of the ADI technique. Due to the longer observing times for respective targets (than those expected to be allocated within the SEEDS project), we estimate that the total exposure times for target stars would be min (corresponding contrast ratio of from 10 5 to 10 4 ). With the sensitivity, we would be able to detect or refute brown drarf mass objects (planetary mass objects) around 4 target stars (around GJ436).

5 Figure 1: An ADI image of HAT-P-7 in H band taken with the Subaru HiCIAO on UT 2009 August 6. 2 candidates of faint stellar companions are clearly detected (Narita et al. 2010, to be submitted). Figure 2: An ADI/LOCI image of one of the proposing targets here taken with the Subaru HiCIAO. A few high SNR regions (brown dwarfs by some chance) can be seen around the central star. Furthermore, we already observed one of the 5 targets (anonymous here) in the SEEDS project in the S09B semester. The ADI/LOCI image is shown in figure 2. As a result, we found that there were a few high signal-to-noise ratio (SNR) regions around the central star (the circles in the figure). We could not confirm natures of these interesting objects, since we only observed one epoch and need to check common proper motions of the objects. Using the Keck/NIRC2, it is feasible to confirm the Subaru/HiCIAO detection, and this planetary system is the highest priority target in the proposing observations. Special Need for Time-Exchange Program: We note that referees or TACs would wonder why we cannot conduct these observations in the SEEDS project at the Subaru telescope. It is because at least some of these targets will not be observed in the SEEDS project in the S10B semester due to a severe overlap of numbers of targets coordinate (namely, optimal observing times for the ADI technique), caused by the 9-month delay of the project due to the malfunction of the Subaru AO188. Also, due to the halt of the SEEDS project, we could not observe a part of the proposing targets in S10A semester, and early restart of the SEEDS project is not surely guaranteed. However, we hope to observe these targets as early as possible (within the 10B semester), since it is a very promising scientific theme and other survey groups may start similar projects in the near future. For the above reason, we propose to observe these targets using 1 night of the Keck telescope through the time-exchenge program. Scientific Benefits: The prime scientific merit of this proposal is that we can certainly answer the migration mechanism of each eccentric or highly tilted transiting exoplanet. Even no detection or detection of only companion stars (very easy with a high contrast imager like the Keck/NIRC2) has important scientific meanings. Also, since these target systems would have massive planets or brown dwarfs with a high rate based on theoretical predictions, detections or stringent constraints of such massive bodies would be indeed interesting. Furthermore, with the proposing observation, we will be able to confirm or refute the possible detection of massive bodies around one of our targets (see figure 2). This is a quite important task and we would like to conduct a follow-up observation in the S10B semester with the Keck/NIRC2, as the SEEDS project may not be able to follow-up this target in the S10B semester. References: Chatterjee, S. et al. 2008, ApJ, 686, 580 Fabrycky, D. & Tremaine, S. 2007, ApJ, 669, 1298 Gaudi, B. S. & Winn, J. N. 2007, ApJ, 655, 550 Hirano, T. et al. 2010, ApJ, 709, 458 Ida, S. & Lin, D. N. C. 2004, ApJ, 616, 567 Lafreniere, D. et al. 2007, ApJ, 660, 770 Lin, D. N. C. et al. 1996, Nature, 380, 606 Marois, C. et al. 2006, ApJ, 641, 556 McLaughlin, D. B. 1924, ApJ, 60, 22 Nagasawa, M. et al. 2008, ApJ, 678, 498 Narita, N. et al. 2009, PASJ Letters, 61, L35 Narita, N. et al. 2010, PASJ Letters, to be submitted Ohta, Y. et al. 2005, ApJ, 622, 1118 Rasio, F. A. & Ford, E. B. 1996, Science, 274, 954 Rossiter, R. A. 1924, ApJ, 69, 15 Tamura, M. et al. 2006, SPIE, 6269 Weidenschilling, S. J. & Marzari, F. 1996, Nature, 384, 619 Winn, J. N. et al. 2009, ApJL, 703, L99 Wu. Y. & Murray, N. 2003, ApJ, 589, 605