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ADDITIONAL SCIENCE POTENTIAL for COROT W. W. Weiss1,2, C

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ADDITIONAL SCIENCE POTENTIAL for COROT W. W. Weiss1,2, C ADDITIONAL SCIENCE POTENTIAL FOR COROT 1;2 1 1 1 1 1 1 W. W. Weiss , C. Aerts , S. Aigrain , G. Alecian ,E.Antonello , A. Baglin , M. Bazot , 1 1 1 1 1 1 A. Collier-Cameron , St. Charpinet ,A.Gamarova , G. Handler , A. Hatzes , A.-M. Hub ert , 1 1 1 1 1 1 1 H. Lammer , T. Lebzelter , C. Maceroni , M. Marconi , D. de Martino , E. Janot-Pacheco ,I.Pagano , 1 1 1 1 1 1 1 1 E. Paunzen , F.J.G. Pinheiro ,E.Poretti ,I.Ribas , V. Rip epi ,F.Roques , R. Silvotti , J. Surdej , 1 1 1 G. Vauclair ,S.Vauclair , and K. Zwintz 1 COROT Additional Program Working Group 2 Department of Astronomy, University Vienna, Tuerkenschanzstrasse 17, A-1180 Wien, Austria Abstract { archival data. Successful prop osals will have to address science outside the primary goals and will get access Space exp eriments which are aiming towards astero- to sp eci c archival data for proprietary use, but ex- seismology and the detection of exoplanets, like corot or clusively in the context of the science addressed in the most, eddington and kepler, are designed to deliver prop osal. high precision photometric data. Obviously, the they can { short runs ( 5to20days) devoted to sp eci c target b e used also for other purp oses than the primary science elds. goals and in addition many other targets can or will be { long runs (up to 130 days). Ab out 100 windows of the automatically observed simultaneously with the primary exoplanet elds will b e available for additional science. targets. As a consequence, fascinating p ossibilities for ad- { windows. During short runs of the core program, it ditional (parallel, secondary) science pro jects emerge. For will also b e p ossible to apply for sp eci c windows in corot a dedicated working group was thus established the exoplanet elds. with the goal to contribute any useful information which Asteroseismological programs using the exoplanetary CCDs may optimize the scienti c output of the mission. are considered to b e part of the AP, as are exoplanetary programs using the seismology CCDs. Key words: COROT { Stars: variable, pulsating { Aster- In order to prepare the AO mentioned ab ove and to oseismology { Exoplanets help de ning the corot science, an Additional Program Working Group (APWG) was established. All resp onse to the AOwillbeevaluated bythecorot Scienti c Committee, whichwillbeincharge for the selec- tion, taking into account the quality of the prop osed sci- 1. Introduction ence. A successful prop oser will obtain status of a Guest COROT (COnvection, ROtation and planetary Transits) Investigator and will have exclusive data rights for the is based on ultra high precision, wide eld, relativestellar science describ ed in his prop osal. The corot Scienti c photometry for very long continuous observing runs in the Committee, however, will have the rights to use the same same eld of view. data for any other science. It has two main scienti c programs working simultane- One year after the rst release of data to the Co- ously on adjacent regions of the sky: asteroseismology and/or Guest-Investigators the data will b e available for & extrasolar planet search. the public. The corot instrument is a white-light wide- eld pho- tometer with an entrance pupil of 27 cm and a set of 4 3. The additional science frame-transfer CCDs as detectors. Two CCDs are devoted to asteroseismology (defo cussed, un ltered light), resp ec- In the context of the Additional Program various asp ects tively to exoplanet search (fo cussed, color information). of variabilitywere discussed. In the following subsections corot will b e launched in mid of 2006 on a low-earth p o- we describ e with some arbitrarily chosen examples the lar inertial orbit, allowing it to monitor continuously stel- corot additional science p otential. For some of the pre- lar elds near the pole of the orbit for ab out 5 months. sented target groups no members are yet known within The mission lifetime will b e nominally 3 years. the visibility region of corot, but dedicated surveys may change this situation. Many of the ideas outlined in the following, are elab o- 2. The Additional Program (AP) concept rated in more detail by memb ers of the corot Additional Program Working Group in the p oster section of these The Additional Program (AP) section of corot will be pro ceedings and the reader is encouraged to browse the available to the community after an AnnouncementofOp- table of content for authors name and/or topic. Further p ortunity(AO) and has the goal to maximize the scienti c information can b e found at return of the mission. This will b e achieved by using Pro c. 2nd Eddington workshop \Stel lar Structure and Habitable Planet Finding",Palermo, 9{11 April 2003 (ESA SP-538, July 2003, F. Favata, S. Aigrain eds.) a) b) http://www.astrsp-mrs.fr/pro jets/corot/ selecting the link "meetings" and further the contributions to the various corot Science Weeks. All science addressed in the following will b ene t from or b e made p ossible by the high photometric quality of the data obtained during power long and uninterrupted observing sequences provided by normalised flux corot. ariability not caused by pulsation 3.1. V time (days) frequency (micro Hz) 3.1.1. Kuiper belt objects, Exo-comets transits Figure1. a): Total solar irradiance light curve from PMO6 The discovery of hundreds of transneptunian ob jects has data, covering the period 1996-2001. b): Power spectrum of the light curve, with a multiple powerlaw t with threecomponents con rmed the hyp othesis of a residual protoplanetary disk (active regions, meso-granulation and granulation) overlaid. beyond Neptune. The knowledge of the structure of this residual disk is a key element to reconstruct the history of the Solar System, but the large distance (up to 100 AU (Ro dono et al. 1995, Lanza et al. 1998), and to measure ro- and even b eyond) excludes the direct detection of ob jects tation and stellar di erential rotation. This information is smaller than some tens of kilometers. Moreover, the ob- fundamental to test the available hydromagnetic dynamo jects already detected show a steep size distribution with mo dels. the consequence that most of the disk mass is in the small, Variability on time scales of hours to days is thought hitherto undetectable ob jects. to be due to distributed networks of smaller structures, Ro ques & Moncuquet (2000) demonstrated that seren- rather than a few active regions or sp ots. This is the range dipitous stellar o ccultations could be a powerful to ol to of time scales that is most critical for planetary transit de- detect these small ob jects orbiting b eyond Neptune if they tection, as it corresp onds to the duration of a typical tran- are dense enough in the sky plane. A dedicated program sit. The identi cation and characterisation of the surface with corot will allow the detection of very small ob jects structures involved is underway for the Sun using soho and will constrain their size distribution. data (Fligge et al. 2000). corot data will allowthistobe A by-pro duct of the exoplanet search program could done for the entire range of stars observed, yielding the b e the detection of exo-comets. In the Pictoris system, relative coverage, contrast, rotation of the various typ es comet-like ob jects falling onto the star have b een detected of structures. These will b e included in irradiance mo dels by their signature in the stellar sp ectrum. Such ob jects currently applicable to the Sun only (Unruh et al 1999, could also b e discovered by the comet tail transit in front Krivova et al. 2003). of the star. corot data and the improved knowledge of intrinsic stellar variabilitywe will gain from it will b e used to test 3.1.2. Pre-main-sequence stars and re ne ltering to ols designed to minimise the e ect of stellar activity on transit detections ahead of missions The photometric study of TTauri stars, a subgroup of suchaseddington and kepler (Carpano et al. 2003). PMS stars, provides valuable information on p erio dic phe- Finally, the monitoring of a few dMe are stars in the nomena, such as the rotational mo dulation due to hot/cold seismology channel could help in shedding some lighton sp ots on the stellar surface, or non-p erio dic, like accretion the mechanisms of coronal heating by investigating the events and ares. The characterisation of such photomet- statistics of white-light stellar micro/nano- ares and re- ric variabilities will help to determine the conditions which lated precursor phenomena and assessing the power law may cause pulsation in solar-typ e PMS stars. distribution of very low energy events. 3.1.3. Stellar activity and flares 3.1.4. Stellar rotation The activitylevel and the characteristic time scales of the It is now observationally well established that stars with luminosity variations of magnetic active late-typ e stars masses similar to or b elow that of the Sun initiate their will b e monitored by corot b etter than ever b efore what lives at the main sequence as relatively fast rotators, with will improve signi cantly our knowledge of stellar intrinsic asso ciated strong high-energy chromospheric and coronal variability on all time scales (Fig. 1). Studying the bright- emissions resulting from magnetic pro cesses. In addition, ness variations on time scales of days to weeks will al- observations suggest that young stars exhibit high rates of low us to detect small solar-like sp ots, derive the lifetimes powerful are events and have dense stellar winds.
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